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Vol.21 Post COVID-19 tests: Suggested Tests After Recovering from Coronavirus

Last Updated 16 July 2021. Cellspect Co., Ltd.

Normally, a COVID-19 patient as mild case usually takes around 2 weeks, while a serious infected takes about a month. According to CDC, adults with mild to moderate COVID-19 remain infectious no longer than 10 days after symptom onset. Most adults with more severe to critical illness or severe immunocompromised likely remain infectious no longer than 20 days after symptom onset.


Even though COVID-19 recovery rate is above 90 per cent, various studies and report shows that many patients who recovered from COVID-19 and tested negative for the virus later tested positive again. Many patients, who recover from COVID-19 disease, suffer post-covid complications and it became difficult for them to live the same old life. It has been observed that the SARS-COV-2 virus can leave long-lasting, lingering side effects long after the viral load has depleted. The virus can also affect the functioning of the many vital organs of the body and hamper immune response. At this time, no laboratory test can definitively distinguish post-COVID conditions from other etiologies, in part due to the heterogeneity of post-COVID conditions. 


Doctors and scientists reveal that recovered patients should also get themselves vaccinated and do activities to maintain their health. Meanwhile, there are several markers inside our blood and immune system which can reveal to what extent the body is affected by the virus. Even though a person recovers from COVID-19, he/she still needs to be cautious and hence, instead of simply testing negative, post-recovery tests are recommended for patients. Post-recovery tests do not focus on viral test (i.e., RT-PCR or antigen test can help assess for current infection.) If you have recovered from Covid-19, here are a few tests and scans suggested to avoid severe health complications later.

7 Suggested Tests Post Recovery from Covid-19

   1. IgG antibody tests: The proteins created by our body’s immune system soon after we have been infected or vaccinated are

      known as antibodies. The IgG antibody tests look for antibodies in your blood to determine if you had a past infection with the

      virus that causes COVID-19. According to experts, after defeating the infection, the body produces helpful antibodies that

      prevent future infections. By knowing the level of antibodies, you will get an idea of how immune-protected you are and

      whether you should donate your plasma or not. To donate plasma, get your IgG test done within a month of recovery.

   2. Complete Blood Count (CBC) tests: CBC tests are being done to measures the different types of blood cells (RBCs, WBCs,

     Platelets). Through this test, you will get to know how well you have responded to a COVID infection. This also gives you a

     guidance about the additional measures that you may need to take post-recovery.

   3. Glucose, cholesterol tests: The virus can also cause fluctuation in the glucose and blood pressure levels of a COVID-19

     positive patient. Hence, this test is considered as crucial if you have pre-existing conditions such as Type-1, Type-2 diabetes,

     cholesterol or are prone to cardiac complications.

   4. Vitamin D test: It is proven that Vitamin D is an important nutrient that supports our immune function. Vitamin D

     supplementation could be crucial during recovery from Covid-19. The Vitamin-D test would give you a fair idea about any

     deficiency in the body that may have been caused due to COVID-19.

   5. Neuro-function tests: Weeks and months after recovery, many patients report neurological and psychological problems and

     hence brain and neurological function tests are suggested to patients, weeks after recovery. It is observed that women over the

     age of 40 are more prone to brain fog, anxiety, tremors, dizziness and hence, they may need priority testing as well.

   6. Chest scans: Many people who have been recovering from COVID-19 are complaining about problems related to lung.

     Hence, HRCT (high-resolution computerized tomography) scans are advised to know accuracy in detecting disease severity

     and knowing the level of lung involvement caused by COVID-19.

   7. Heart imaging and cardiac screenings: Experts believe that COVID-19 infection triggers widespread inflammation in the body,

     causing damage of heart muscles, arrhythmias and lead to complications such as myocarditis, which is one of the most

     common post-COVID recovery problems reported in people. Getting proper imaging scans and heart function tests should be a

     priority for people, especially if they suffered from a moderate or severe infection. People who complain of chest pain as their

     COVID symptom should take special precautions and schedule tests, warn doctors.


  1. CDC: Evaluating and Caring for Patients with Post-COVID Conditions: Interim Guidance

  2. The pathology specialist: Recovered from COVID? Post COVID care and health tests you must take. Jun 01, 2021. Metropolis Healthcare

  3. Post COVID-19 Care: Tests You Must Take After Recovering from Coronavirus. May 13, 2021. News 18.

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Vol.22 Post COVID-19 tests: Suggested Tests After Recovering from Coronavirus

Last Updated 30 July 2021. Cellspect Co., Ltd.

Scientists of University of Fukui in Japan found or the first time that short chain fatty acids can be used to reduce susceptibility to SARS-CoV-2 infection and mortality from COVID-19.

It is now well known that SARS-CoV-2 uses “spike proteins” to get inside our cells by binding to a protein called angiotensin-converting enzyme 2 (ACE2) that is found in our cells. The nasal mucosa has the highest expression of ACE2 in all human organs, and therefore is the critical target of initial infection of SARS-CoV-2. Interestingly, recent studies have shown that patients with COVID-19 who have rhinosinusitis (i.e., inflammation of the nose) have a low risk of hospitalization. Moreover, the expression of ACE2 was reduced in patients with rhinosinusitis. Coincidentally, another study has shown that short-chain fatty acids (SCFA), produced by bacteria in the gut have beneficial effects in allergy and viral infections. 

These separate findings prompted an investigation of the effect that SCFAs in the nasal cavity against SARS-CoV-2 infection by scientists from the University of Fukui, Japan, led by Dr. Tetsuji Takabayashi. They have found that nasal inflammation can influence susceptibility to SARS-CoV-2. They also identified the use of short chain fatty acids as a potential COVID-19 management strategy. This study was published in the American Journal of Rhinology & Allergy. “This is the first report that short-chain fatty acids (SCFAs) effectively reduce the ACE2 levels in human airway epithelial cells,” remarks Dr. Takabayashi. 

To understand the status of ACE2 expression in patients with allergies, the researchers studied the levels of ACE2 in the inner lining of the nose in patients with seasonal allergic rhinitis induced by Japanese cedar pollen (SAR-JCP) and chronic rhinosinusitis (CRS). Using techniques like real time-PCR to quantify the expression of ACE2, the researchers found that there was no increase in ACE2 expression in in patients with SAR-JCP, whereas it was decreased in patients with CRS.

To better understand the effect of SCFAs on ACE2 expression, the researchers cultured nasal epithelial cells and exposed them to either SFCA and double-stranded RNA (similar to the nuclear material found in some viruses and known to enhance ACE2 expression). Upon examining the expression of ACE2, the researchers saw that the SFCAs had suppressed ACE2 expression in the presence of the RNA as well.

A previous study has similar results in support of the current findings. Researchers of University of Campinas (UNICAMP) in the state of São Paulo, Brazil, shows that viral load wasn't reduced in cells and tissue treated with SCFAs and in untreated samples. However, treated intestinal biopsy samples displayed a significant decrease in expression of the protein TMPRSS2, which is another important protein for viral cell entry. Moreover, it also reduced the expression of a gene that plays a key role in viral cell entry and a cytokine receptor that favors inflammation.

These results suggest that SFCAs has potential therapeutic applications against COVID-19. Therefore, the development of strategies to downregulate ACE2 expression, such as using SFCA in nasal epithelial cells, could reduce SARS-CoV-2 transmission and be useful as a novel therapeutic approach.”


  1. “Short Chain Fatty Acids: An “ACE in the Hole” Against SARS-CoV-2 Infection” News from University of Fukui

  2. Tetsuji Takabayashi et al. Jun 7, 2021. “Regulation of the Expression of SARS-CoV-2 Receptor Angiotensin-Converting Enzyme 2 in Nasal Mucosa” American Journal of Rhinology & Allergy

  3. Lívia Bitencourt Pascoal et al. Feb 28, 2021. “Microbiota-derived short-chain fatty acids do not interfere with SARS-CoV-2 infection of human colonic samples” Gut Microbes

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Vol.23 Immunogenicity bridging? Japan's Daiichi Sankyo mRNA vaccine phase III clinical trial will be compared with Pfizer or Moderna 

Last Updated 20 August 2021. Cellspect Co., Ltd.

Japan currently does not have an approved domestic COVID-19 vaccine, and the vaccination of its citizens are completely dependent on the government's active ordering of foreign manufacturers. However, Japan has not neglected the development of domestic vaccines, and the progress has continued to move forward steadily. At present, there are already four manufacturers in Japan, and a total of five COVID-19 vaccines are undergoing clinical trials.

As the number of people who have not received the COVID-19 vaccine decreases, drug regulatory agencies in the United Kingdom and Japan are promoting the use of test platforms to conduct second-generation COVID-19 vaccine-related trials. In an online seminar organized by the International Coalition of Medicines Regulatory Authorities (ICMRA) on June 24, representatives from the Japan Pharmaceuticals and Medical Devices Agency (PMDA) and the British Medicines and Healthcare products Regulatory Agency (MHRA) proposed to use the "new platform" new study design, or through several single active comparators, to evaluate the efficacy of the COVID-19 vaccine. Participants said that due to the continuous expansion of the scale of vaccination, it has become more and more difficult to conduct traditional placebo-controlled studies. Therefore, it is necessary to seek alternative clinical trial designs through these "non-inferiority" trials. 

As for assessing the effectiveness of vaccine, there was consensus that immunogenicity bridging studies may be needed for assessing effectiveness of second-generations COVID-19 vaccines if clinical endpoint efficacy studies are no longer feasible. In such trial design, the selection of immune markers to predict effectiveness, and comparison with the population matched with the previous vaccination, age and sex, is a key factor to confirm that the trial vaccine is consistent with the comparison group.

Currently, Daiichi Sankyo announced that the Phase III clinical trial of its COVID-19 mRNA vaccine (DS-5670) will adopt a "non-inferiority" trial this autumn, that is, to prove that the efficacy of this candidate vaccine can be equivalent to that of Pfizer/BioNTech and Modena's vaccines, or even better.

Although Daiichi Sankyo has not announced the detailed test details, the following may some points needed to pay attention to.
 1. The non-inferiority comparison trial may only be carried out among vaccines with the same technology platform. For example,  Daiichi Sankyo is an mRNA vaccine, and the comparison object will be Pfizer/Moderna, etc. If people want to use this method  with protein subunit vaccines in the future, the comparison object may be quite limited.
 2. The trial is a phase III clinical trial, so it must reach a sufficient trial scale (thousands to tens of thousands of participants)
 3. The end-to-end comparison targets with Pfizer or Moderna vaccines, according to the Phase 2 clinical trials of the Daiichi  Sankyo, is very likely to be neutralizing antibodies and IgG antibody titers. Therefore, the selection of control group, the standard  of neutralizing antibody/IgG titers, and how to set the clinical trial endpoint will be critical. In addition, how to track the duration of  vaccine protection is also an important problem.

So far, Japan's Daiichi Sankyo mRNA Covid-19 vaccine (DS-5670) has shown good safety and effectiveness in clinical data. In the long run, the development of DS-5670 can ensure that Japan has the ability to respond to new or variant pathogens more quickly.

In addition, the recombinant protein vaccine candidate "S-268019" of Shionogi & Co., Ltd. are also planning to conduct large-scale Phase III trials in Southeast Asia and other regions. Moreover, Shionogi has signed a license agreement with HanaVax, a drug discovery and innovation company from the University of Tokyo, to use HanaVax's cationic nanogel delivery system (cCHP) to develop a new nasal vaccine candidate for COVID-19. cCHP is HanaVax's unique delivery technology using pullulan with cationic cholesterol groups. Intranasal administration can effectively induce respiratory mucosa and systemic immunity without the pain caused by conventional injections.

With the escalating pandemic everywhere, people all over the world sincerely hope that the pandemic can be ended with these vaccines.


  1. Jul 19, 2021 “Global regulators promote platform trials to assess new COVID vaccines” Regulatory Affairs Professionals Society

  2. Jun 24, 2021. “ICMRA COVID-19 Vaccine development: Future steps Workshop” ICMRA

  3. KENYA AKAMA et al., Jun 13, 2021. “Japan nears homegrown vaccine with Daiichi Sankyo Phase 3 trials” Nikkei Asia

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Vol.24 Will virtual primary care become a new model of healthcare delivery? The future vision of virtual care

Last Updated 27 August 2021. Cellspect Co., Ltd.

During the pandemic, the telehealth becomes a viable long-term option for consumers. Telehealth services help provide necessary care to patients while minimizing the transmission risk of SARS-CoV-2 to healthcare personnel (HCP) and patients. In the United States, the number of people using telemedicine has grown from 11% in 2019 to 46% in 2021. Providers have rapidly scaled offerings and are seeing 50 to 175 times the number of patients via telehealth than they did before. A recent survey by Social Sciences Research Solutions found 90% of patients in the US were satisfied with their telehealth care and would use the service again, with 80% saying their medical issue was resolved as a result of the virtual visit. Telemedicine, which enables video or phone appointments between a patient and their health care practitioner, benefits both health and convenience. More health care providers are offering to “see” patients by computer and smartphone. 


Recently, however, a new term "virtual care" has appeared, and what is the difference between virtual care and telehealth?


The term telemedicine or telehealth refers specifically to the treatment of various medical conditions without seeing the patient in person. Healthcare providers may use telehealth platforms like live video, audio, or instant messaging to address a patient’s concerns and diagnose their condition remotely. This may include giving medical advice, walking them through at-home exercises, or recommending them to a local provider or facility. On the other hand, virtual care (or VPC, virtual primary care) is a broad term that encompasses all the ways healthcare providers remotely interact with their patients. In addition to treating patients via telemedicine, providers may use live video, audio, and instant messaging to communicate with their patients remotely. This includes checking in after an in-person visit, monitoring vitals after surgery, or responding to any questions about their diagnosis, condition or treatment plan. 


Simply put, the term virtual care is a way of talking about all the ways patients and doctors can use digital tools to communicate in real-time. While telemedicine refers to long-distance patient care, virtual care is a much broader term that refers to a variety of digital healthcare services. Therefore, although people sometimes mix use these terms, when discussing the digitization of healthcare, it’s usually best to use the term virtual care instead of telemedicine. The latter has a more limited definition, while virtual care paints a more comprehensive picture of the modern healthcare landscape, which includes telemedicine as well.


According to statistics from Fair Health, a non-profit medical promotion agency in the United States, although the number of COVID-19 cases has gradually declined and many patients have gradually returned to t in-person consultation, but the number of telehealth has stabilized in May and has not been significantly reduced. From April to May this year, the utilization rate of private insurance for telemedicine increased by 2% (measured as a percentage of overall medical insurance claims).


The virtual health/telehealth boom has also fueled a burst of M&A activity. Earlier this year, Cigna's Evernorth health services business acquired telehealth provider MDLive for an undisclosed sum. The insurer plans to sell MDLive's telehealth offerings to third-party clients and offer it to beneficiaries. At-home testing company Everlywell expanded their business into telehealth by purchasing PWNHealth and another at-home lab testing company. Teladoc itself paid $18.5 billion last year to buy chronic care manager Livongo. In July, Amwell, a telemedicine platform, also acquired SilverCloud Health and Coversa Health for US$320 million to improve the follow-up treatment and care of its telemedicine clinics. Amazon is also expanding its virtual care pilot program, Amazon Care, to employees and outside companies nationwide beginning this summer, offering preventative care like annual vaccinations, to urgent care including COVID-19 testing, to services like family planning.


Apparently, virtual primary care has become a new model of healthcare delivery. But there is another important issue that how to support and sustain virtual care?


Virtual primary care can reduce costs for health plans by providing proactive care rather than reactive, and by encouraging recommended screenings and closing gaps in care. This is especially important considering the fact that during COVID-19, one in five adults delayed care in the first year of the pandemic. Moreover, as is commonly said in healthcare, “no margin, no mission.” Health systems are challenged to develop business models that can sustain their virtual services. Most health systems derive the bulk of their revenue through fee-for-service (FFS) reimbursement which, prior to the pandemic, was quite limited for virtual care. Virtual care may fit better under alternative (non-FFS) risk-based payment models, which create incentives and increase flexibility to redesign care in ways that best meet patient needs. To further decrease costs, virtual primary care programs can help health plans keep care in network and drive members toward other in-network services and on-formulary medications, all of which are associated with cost savings and improved coordination for health plans and employers. For example, physicians should have access to a list of preferred laboratories, formularies and in-network providers in real time during the patient visit, making it easier for them to direct patients to preferred providers that are lower in cost for patients as well as health plans.


Irrespective of the revenue model, virtual care may enable health systems to reduce costs. Though it may initially require as much or even more staff time than in-person care, efficiency should improve over time, and a shift to more self-service could drive productivity. Likewise, systems that move enough in-person care to virtual may be able to reduce their footprint, or at least reconfigure their space to be more flexible and less costly.


The pandemic forced healthcare systems to rapidly expand their virtual care offerings. As the pandemic stabilizes and eventually recedes, many will be tempted to completely roll back to traditional in-person care. However, virtual care is no longer just an optional but a basic expectation and a much-needed opportunity to advance high-value, technology-enabled, person-centered care. Although change is never easy and the benefits may be delayed, health systems must continue to build and implement useful and usable virtual solutions, then integrate them into their broader care and operational models in ways that benefit their organizations and the communities they serve.


  1. Spencer D. Dorn, 2021 “Backslide or forward progress? Virtual care at U.S. healthcare systems beyond the COVID-19 pandemic” npj digital medicine

  2.  “Using Telehealth to Expand Access to Essential Health Services during the COVID-19 Pandemic” CDC Guideline

  3. Rebecca Pifer, March 17 2021, “Amazon Care goes nationwide with telehealth, courts outside employers” Healthcaredive

  4. Susan Kelly, August 11 2021, “CVS Health's Aetna unveils nationwide primary care telehealth service” Healthcaredive

  5. Bill Siwicki, May 24 2021, “Will virtual primary care become a new model of healthcare delivery?” HIMSS

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Vol.25 Summary of COVID-19 pathogenesis and potential for cell therapies

Last Updated 10 September 2021. Cellspect Co., Ltd.

On August 11th, George Church, who is known as the father of synthetic biology, and a number of scientists published a review article in "Science Advances", explaining the harm caused by the novel coronavirus to the human body, and the potential of cell therapy on severe and sequelae. According to the research team's statistics, as of January 1, 2021, there are 89 cell therapy clinical trials for the novel coronavirus over the world. 88% of them are still in clinical phase 1 or phase 2, only 1 trial entered phase 2/3 and the other 1 trial entered phase 3, suggesting that cell therapy for Covid-19 is still in its early stages.

SARS-CoV-2, virus causing COVID-19, initially emerged as a pathogen causing mainly viral pneumonias and then the disease manifests throughout the body in the proceeding months, leading to pathologies of the immune, renal, cardiac, and nervous systems, among others. While most patients have a mild course, over 15% develop severe illness, leading to a substantial number of patients requiring prolonged hospitalization with intensive care services and potentially facing subsequent chronic manifestations related to pathological injuries from the disease process. In addition, mortality can be as high as 61.5% in critically ill patients with the disease. Even if patients recover, them may still face long-term sequelae caused by virus damage to your body's tissues in the future.

Binding to the ACE2 receptor on the cell surface is the most important way for the virus to invade the cell. The highest position of ACE2 in the respiratory tract is the epithelial cells of the nasal cavity, which is also the starting point for infection of the human body. As the virus spreads, it gradually infects the alveoli. However, in addition to the lungs, the intestines, kidneys, bladder, and heart are also organs with high ACE2 expression. Therefore, the impact of new coronary pneumonia on patients is not only the respiratory system, but also a wide range of other system injuries, including cardiovascular, nervous, immune, kidney and other organ systems. In addition, current treatments for Covid-19 are nonspecific and have not focused on long-term sequela of the disease such as pulmonary fibrosis, demyelination, and ischemic organ damage. Cell therapies may thus be promising due to their customizability and regeneration ability of damaged tissue structures and functions.

Among the respiratory symptoms, mesenchymal stem cell (MSC) is the most expected in the relief of pneumonia and acute respiratory distress syndrome (ARDS). In the treatment of pulmonary fibrosis, in addition to MSC, the use of type II pneumocytes also showed efficacy in preclinical animal trials. As to immune system, the antibody-dependent enhancement (ADE) caused by the novel coronavirus may cause the virus to attack monocytes, macrophages, B cells, etc., and may hinder the function of T cells. On the other hand, viral infection may also increase the concentration of pro-inflammatory cytokines in the immune system, and even trigger a cytokine storm in severe ill patients. For these symptoms, those that have entered clinical trials, including: natural killer (NK) cells, regulatory T cells (Treg), virus-specific T cells, and even genetically modified CAR NK and CAR-T cells have shown therapeutic potential. In addition, MSC has also become one of the most potential therapies due to its immunomodulatory ability.

As for the myocardial damage caused by the cardiovascular system and the renal damage of the renal system, currently iPSC-derived cardiomyocytes, kidney cells, and MSC are put into clinical trials; hypercoagulability and disseminated intravascular coagulation (DIC), which causes vascular endothelial damage, has the opportunity to regulate the growth of blood vessels through CD34+ cell therapy. However, there is currently no clinical trial of cell therapy for the neurological damage caused by new coronary pneumonia. in addition, there is little chance of occurrence of gastrointestinal symptoms because of chronic sequelae, and there is no clinical trial investment.

The following figure shows a summary of COVID-19 pathogenesis (blue text) and potential of cell therapies (green text) by organ system. 


  1. Zaki et al., August 11 2021, “Cell therapy strategies for COVID-19: Current approaches and potential applications” Science Advances Vol. 7, no. 33, eabg5995. DOI: 10.1126/sciadv.abg5995

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Vol.26 What is Covid-19 Breakthrough Infection? What the science says?

Last Updated 24 September 2021. Cellspect Co., Ltd.

・What is Covid-19 Breakthrough Infections 
Recently, more and more breakthrough infections, including infections among health care workers have been reported. What is breakthrough infection? A breakthrough infection is a case in which a vaccinated individual becomes sick from the same illness that the vaccine is meant to prevent. Simply, they occur when vaccines fail to provide immunity against the pathogen they are designed to target. According to CDC’s definition, a COVID-19 breakthrough infection is the detection of SARS-CoV-2 RNA or antigen in a respiratory specimen collected from a person ≥14 days after they are fully vaccinated with a COVID-19 vaccine.


・Can the vaccine not protect against the Delta variant?

When early field data showed that vaccinating people cuts transmission of the SARS-CoV-2 virus, researchers were cautiously optimistic. However, after the Delta variant tore through India and the world with alarming speed in April and May, current reports from various countries seem to confirm what scientists feared: Delta is more likely than other variants to spread through vaccinated people. Below we summarize the latest research on Delta variant and explore why Delta variant are prone to cause breakthrough infections.


The French research team published a study in "Nature" in July. This studies have found that Delta variant was resistant to neutralization by some anti-NTD(N-terminal domain) and anti-RBD(Receptor-binding domain) monoclonal antibodies, such as bamlanivimab. The target of Bamlanivimab is RBD and the L452R mutation on the RBD of the Delta variant results in the weakening of the binding ability of the monoclonal antibody and the spike protein, which is the possible reason why Bamlanivimab cannot effectively neutralize the Delta variant. Moreover, sera collected from convalescent individuals up to 12 months after the onset of symptoms were fourfold less potent against the Delta variant relative to the Alpha variant (B.1.1.7). Sera from individuals who had received one dose of the Pfizer or the AstraZeneca vaccine had a barely discernible inhibitory effect on the Delta variant. Administration of two doses of the vaccine generated a neutralizing response in 95% of individuals, with titers three- to fivefold lower against the Delta variant than against the Alpha variant. Thus, the spread of the Delta variant is associated with an escape from antibodies that target non-RBD and RBD epitopes of the spike protein.


In the same month, Israel also completed monitoring 12,586 medical personnel for breakthrough infections at its largest medical center, Sheba Medical Center. As of the end of April 2021, 91% of personnel have received two doses of Pfizer/BNT vaccine. Results show that among 1497 fully vaccinated health care workers for whom RT-PCR data were available, 39 SARS-CoV-2 breakthrough infections were documented. Neutralizing antibody titers in case patients during the peri-infection period were lower than those in matched uninfected controls (case-to-control ratio, 0.361; 95% confidence interval, 0.165 to 0.787). Higher peri-infection neutralizing antibody titers were associated with lower infectivity (higher Ct values). Most breakthrough cases were mild or asymptomatic, although 19% had persistent symptoms (>6 weeks). The B.1.1.7 (alpha) variant was found in 85% of samples tested. A total of 74% of case patients had a high viral load (Ct value, <30) at some point during their infection; however, of these patients, only 17 (59%) had a positive result on concurrent antigen tests. No secondary infections were documented. They concluded that among fully vaccinated health care workers, the occurrence of breakthrough infections with SARS-CoV-2 was correlated with neutralizing antibody titers during the pre-infection period. The study was published in "Nature" as well.


Another study published in "Nature" in August pointed out that COVID-19 test data in the United States, the United Kingdom, and Singapore found that vaccinated and unvaccinated people carry the same amount of virus load in their noses after being infected with Delta SARS-CoV-2. This means that although vaccines can provide protection, some people who are vaccinated can still be infected with Delta virus. "People who carry the Delta virus and happen to have a breakthrough infection may have a very high number of these viruses and unknowingly spread the virus to others." The researchers emphasized that the COVID-19 vaccine can prevent serious illness and death, but the data shows that "people who are vaccinated still need to take protective measures."


The latest research published in "The New England Journal of Medicine" in September has pointed out that because the Delta virus strain has more spike proteins on its surface, it is easier to replicate and penetrate into cells. The Delta variant is able to avoid the antibodies produced after complete inoculation of 2 doses of AZ or Pfizer/BNT vaccine, and the ability to cause breakthrough infection is 8 times that of the original virus strain. The researchers also tested the neutralizing ability of the antibodies against the Delta, Alpha mutant strains and the original virus strains with antibodies in the body of the infected persons. They found that the ability of the antibodies to neutralize the Alpha virus strain was 2.3-fold lower than that of the original virus. As for neutralize the Delta virus variant, the capacity has dropped by 5.7-fold.

To sum up, Delta variants obviously bring variables after being vaccinated. Delta variant Experts all suggest that even if two doses of the vaccine have been vaccinated, some occasions may still need to wear a more protective Masks, continue to maintain social distancing, before the birth of the Delta variant virus vaccine, it is also necessary to inject the third booster shot. At the same time, serious consideration should be given to the development of a special vaccine against the Delta variant.


  1. Petra Mlcochova et al., Sep 6 2021, “SARS-CoV-2 B.1.617.2 Delta variant replication and immune evasion” Nature.

  2. Nidhi Subbaraman, Aug 12 2021, “How do vaccinated people spread Delta? What the science says” Nature.

  3. Delphine Planas et al., Jul 18 2021 “Reduced sensitivity of SARS-CoV-2 variant Delta to antibody neutralization” Nature.

  4. Moriah Bergwerk et al., Jul 28 2021, “Covid-19 Breakthrough Infections in Vaccinated Health Care Workers” N Engl J Med.

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Vol.27 When will COVID-19 become seasonal flu? When will the pandemic end?

Last Updated 8 October 2021. Cellspect Co., Ltd.

Although the Delta variant virus is still the main epidemic virus in the world, as the vaccination rate increases, it seems that severe illnesses and deaths appear to be less and less. A study published in the Journal of Lancet Infectious Disease on September 1st analyzed the associations between risk factors and post-vaccination infection, and the associations of individual symptoms, overall disease duration, and disease severity with vaccination status among over 1 million vaccinated people in UK. The study concluded that the vaccine can still provide protection against severe illness, hospitalization and sequelae, and the risk of breakthrough infection is extremely low.

Meanwhile, on Sep 22, Professor Dame Sarah Gilbert in the Royal Society of Medicine webinar that the novel coronavirus is unlikely to mutate into deadlier variant and will end up as a common cold. Professor Dame Sarah Gilbert is the person who led the team at Oxford University's Jenner institute to create the lifesaving AstraZeneca Covid-19 vaccine, the most widely distributed jab in the world. 'We already live with four different human coronaviruses that we don't really ever think about very much and eventually Sars-CoV-2 will become one of those. It's just a question of how long it's going to take to get there and what measures we're going to have to take to manage it in the meantime.' she said.


When will COVID-19 become seasonal flu? When will the pandemic end? Here we concluded the opinions from experts in Harvard T.H. Chan School of Public Health.

History tells us that deadly viruses such as COVID-19 can, over time, will become manageable threats

We know of a few respiratory viruses that were introduced into the human population, swept across the globe, and transitioned to endemic circulation, usually with annual wintertime peaks in incidence. The example most commonly invoked these days is the 1918 flu pandemic, caused by an A/H1N1 influenza virus. COVID-19 is just the same. The pandemics generally began with infection fatality rates higher than observed in the years following their introduction as the viruses continued to circulate. While declining fatality rates after pandemics may be due to a number of factors, one likely key contributor is that the first round of exposure to a pathogen confers some degree of protection against reinfection and severity of disease if reinfection does occur. Vaccines confer protection in much the same way, as the data from the COVID-19 vaccines has demonstrated.


What’s a likely timeline for COVID-19 to become endemic?

The expectation that COVID-19 will become endemic essentially means that the pandemic will not end with the virus disappearing; instead, the optimistic view is that enough people will gain immune protection from vaccination and from natural infection such that there will be less transmission and much less COVID-19-related hospitalization and death, even as the virus continues to circulate. Since viruses spread where there are enough susceptible individuals and enough contact among them to sustain spread, it’s hard to anticipate what the timeline will be for the expected shift of COVID-19 to endemicity. It’s dependent on factors like the strength and duration of immune protection from vaccination and natural infection, our patterns of contact with one another that allow spread, and the transmissibility of the virus. It is difficult to remove coronavirus completely and can only coexist with it. Therefore, effective drugs are very important to cope with the COVID-19 epidemic. In the future, only "vaccine" and "drugs" can gradually restore order to the world. Vaccines are unlikely to prevent infections completely, but they can prevent severe illnesses, while drugs can treat mild illnesses.


Past pandemics have led to massive changes in the way we live that we’ve come to accept as normal. This pandemic has brought countless challenges to mankind, and it is slowly showing a trend of convergence. Perhaps the lessons learned from COVID-19 in terms of disease prevention can yield similar long-term improvements in individual and global health.


  1. Michela Antonelli et al., Sep 1 2021, “Risk factors and disease profile of post-vaccination SARS-CoV-2 infection in UK users of the COVID Symptom Study app: a prospective, community-based, nested, case-control study” Lancet Infectious Disease.

  2. ELEANOR HAYWARD, Sep 22 2021, ”Covid is going to just become a cold': Vaccine pioneer says virus will get weaker all the time as Whitty says every child is going to get it, unless they are jabbed” THE DAILY MAIL

  3. Karen Feldscher, Aug 11 2021 “What will it be like when COVID-19 becomes endemic?” Featured News Stories from Harvard T.H. Chan School of Public Health.

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Vol.28 Cue Health's success in COVID test market: the need for COVID-19 testing still huge

Last Updated 22 October 2021. Cellspect Co., Ltd.

The Covid-19 pandemic has gradually subsided after the widespread vaccinations in many countries. Accordingly, many restricted industries have gradually opened up, while some Covid-19-related demands have gradually decreased. Interestingly, regarding Covid-19 test, the prospects still seem to be promising. With the Covid-19 pandemic still far from over and demand for rapid, at-home tests overtaking the supply in the U.S., White House announced to pour billions of dollars to ramp test production and make rapid tests widely accessible on Oct 6.

The latest funding highlights the great, continuous demand of Covid testing for people returning to work and school. Therefore, so far Covid test is still one of the most popular businesses and many test manufacturers also benefit from this. However, popularity also means relative competition. Not all test makers have developed well. One of the most eye-catching is Cue Health, which just went IPO at the end of September. Cue Health went public on Friday at a valuation of nearly $2.3 billion. Shares opened above the $16 price set the night before and closed at $20—a 25% increase in the first day of trading. In the competitive COVID-19 testing market, how can Cue Health achieve such success?

Cue Health was founded in 2010, originally focused on rapid portable flu tests. When the Covid-19 pandemic hit, Cue Health quickly shifted gears and spun up a Covid-19 test. Cue Health received emergency use authorization from the FDA for its point-of-care test in June 2020 and in March 2021, Cue received FDA emergency use authorization for at-home use.

In the saturated Covid-19 testing market, Cue Health test has three competitive advantages. First, Cue Health's rapid COVID-19 test is the first at-home molecular testing kit approved for purchase without a prescription in the United States, and it can be used as young as two. The convenience that it can be purchased at a pharmacy without showing a prescription has greatly accelerated the speed and scope of Covid-19 screening, and it is also easy for the public to obtain.

Second, most of the rapid tests currently focus on antigen detection, but Cue uses molecular nucleic acid amplification test (NAAT) technology to detect the RNA of the Covid-19 virus. Generally speaking, antigen detection reagents may ignore the presence of the virus when the number of antigens is too small, but Cue's kit can detect the RNA of the Covid-19 virus, which means it can detect smaller amounts of the virus in a person’s system and provides more accurate test results in line with PCR tests, the “gold standard” of diagnostics. In the results from FDA-approved laboratories, the kit also showed a false positive rate of 2.6% and a false negative rate of 0.9%, and the probability of detection errors is quite low. Another study conducted by the Mayo Clinic found Cue’s test results to agree with PCR tests over 92% of the time in detecting Covid and over 98% of the time in coming to a negative result.

The third advantage is that Cue's rapid test can be combined with Cue Integrated Care Platform, a mobile app to obtain an analysis report, and it only takes 20 minutes to get the results. Moreover, Cue Health on Oct 6 introduced its new collaboration with Google Cloud to address the nation's critical need for real-time respiratory viral variant sequencing and tracking. The new capabilities will be built into the Cue Integrated Care Platform. By integrating cloud-connected COVID-19 information with sequencing data and AI tools, Cue Health and Google Cloud will equip public health officials and researchers with critical, real-time information about variant types -- including their geographic distribution -- and predictive capabilities to help identify and curb emerging threats.

In addition to the cooperation between Cue and Google, there have been many notable collaborations in the past two years, including the US government agency Biomedical Advanced Research and Development Agency (BARDA), the US Department of Defense, and the NBA. Currently Cue has five other test kits in late-stage development, which the company expects to begin submitting for FDA clearance in the second half of 2022: flu, RSV, fertility, pregnancy and inflammation biomarkers that could indicate risk of heart disease or chronic conditions. The company is starting clinical trials for flu and RSV in the near-term. And beyond the nasal swab, it will also be able to take blood, urine and plasma samples. Because of the wide range of development, this is also the reason why it may give it a promising future.


  1. Andrea Park, Oct 7 2021, “White House funnels $1B into at-home COVID test makers, quadrupling monthly supply by December” Fierce Biotech

  2. Katie Jennings, Sep 24 2021,” Covid Test Maker Cue Health Goes Public At $2.3 Billion Valuation as Demand Surges” Forbes

  3. TYLER CHEN, Sep 27 2021, “Why can Cue Health IPO oversubscribe? Market value exceeds 2 billion U.S. dollars”

  4. Conor Hale, Oct 7 2021, “Cue Health taps Google Cloud to track down COVID variants and connect its portable tests” Fierce Biotech

アンカー 9

Vol.29 Oral drug molnupiravir seen as 'trump card' in the battle against COVID-19. Why it is so important?

Last Updated 12 November 2021. Cellspect Co., Ltd.

Pharmaceutical company Merck applied on October 11 for FDA emergency use authorization for its oral antiviral COVID-19 drug, molnupiravir. If it is authorized by FDA, it would be the first oral antiviral treatment for COVID-19. By contrast, the other currently authorized drugs must be delivered intravenously or injected. 

What is molnupiravir?

Molnupiravir, originally developed to treat influenza, could solve many of these challenges. It is an antiviral pill that aims to prevent mild to moderate cases of covid-19 from becoming severe cases that result in hospitalization or death. People who have covid-19 take the drug twice a day for five days, starting within five days of the onset of symptoms.


The other therapies on offer against COVID-19, Gilead Science’s antiviral remdesivir and a monoclonal antibody cocktail from biotech firm Regeneron, must be administered intravenously or by injection. That makes it difficult for people to access the therapies before they are sick enough to land in hospital. And remdesivir is approved only for those who are already hospitalized with COVID-19. Yet it’s better to “hit early, hit hard” with antivirals. The sicker the patient, the less effective the drugs are at treating the illness. As regard to Molnupiravir, it is an antiviral pill which simply requires a prescription and a trip to the pharmacy once symptoms appear, would make early treatment much easier.

How does molnupiravir work?

Molnupiravir, like remdesivir, is a nucleoside analogue, which means it mimics some of the building blocks of RNA. But the compounds work in entirely different ways. When SARS-CoV-2 enters a cell, the virus needs to duplicate its RNA genome to form new viruses. When Molnupiravir is administered, it is incorporated into the RNA genome of the coronavirus and causes a series of errors that make the virus’s replication harder. On the other hand, remdesivir is a ‘chain terminator’. It stops the enzyme that builds these RNA ‘chains’ from adding further links.

While remdesivir, the first drug approved in the U.S. and Japan for treating COVID-19, works similarly by slowing down RNA replication, scientists think that molnupiravir is a more powerful tool against the coronavirus and has demonstrated efficacy against various variants including gamma, delta and mu.

Of the patients who received a course of molnupiravir, 7.3% were hospitalized by the 29th day after taking it, while 14.1% of those given a placebo had been admitted to hospital or died — no deaths were reported among those who took the drug, against eight deaths in the placebo group. But the compound’s mutagenic potential in human cells — the possibility that it could incorporate itself into DNA — does raise safety concerns, some researchers say. Merck hasn’t released any detailed safety data yet, but said “we’re very comfortable that the drug will be safe if used as intended” at a press briefing.


Are there any side effects?

About 1.3% of people who received the drug discontinued the treatment due to an adverse event, compared with 3.4% in the placebo group. Because of concerns that the mutations caused by the drug could trigger a disruption in RNA replication and cause birth defects, women who were pregnant or breastfeeding were excluded from the clinical trial, while men needed to abstain from heterosexual intercourse or agree to use contraception.

Why molnupiravir could be so important?

At present, experts agree that the novel coronavirus is difficult to completely eliminate and can only coexist with it. Therefore, "vaccine" and "oral medicine" are key "game-changer". Vaccines can greatly reduce infections and prevent sever disease, while oral medications can treat patients with mild Covid-19 easier and earlier, keeping hospitals from overflowing. 


Currently, the vaccination rate in most developed countries has slowed down. At the same time, many other countries still don’t have access to enough vaccines. Vaccine distribution efforts in countries that lacked a robust medical infrastructure struggled to get shots in arms, even if they had an adequate supply, as the vaccine doses require extremely cold refrigeration and people trained to administer the shots. The unvaccinated continue to make up the majority of hospitalizations and deaths. Treatments for Covid-19, therefore, remain a vital component of the response to the pandemic. But developing new drugs to treat an illness is expensive and time-consuming, which is why researchers have been eager to find off-the-shelf therapies that have already been deemed safe to use against other ailments. 


New drugs like molnupiravir require more testing and review, but they offer the possibility of a stronger, more targeted approach. A drug like molnupiravir could be especially useful because it is administered in the early stages of the disease. Since it’s just a pill, it may spare the patient a trip to a clinic for a transfusion for treatments like monoclonal antibodies. That reduces the chances of an infected patient transmitting the virus to medical staff, and it averts potential complications associated with transfusions.

In Japan, Shionogi late last month also started a mid- to late-stage clinical trial for its pills and is aiming to enroll around 2,000 subjects with mild or no symptoms of COVID-19. Its oral antiviral drug under development targets another essential protein, known as 3CL protease, to suppress duplication of the virus. Shionogi’s drug only needs to be administered orally once daily for five days by COVID-19 patients with no or mild symptoms.


Treatments do help people get better — but it’s important to remember that vaccination and other measures remain critical too. The arrival of an effective drug won’t be a reason to let our guard down. The existing pillars of pandemic response will remain crucial to keeping this deadly disease in check.


  1. Cassandra Willyard, Oct 8, 2021, “How antiviral pill molnupiravir shot ahead in the COVID drug hunt” Nature news.

  2. Oct 11, 2021” Merck and Ridgeback Announce Submission of Emergency Use Authorization Application to the U.S. FDA for Molnupiravir, an Investigational Oral Antiviral Medicine, for the Treatment of Mild-to-Moderate COVID-19 in At Risk Adults” Merck News Releases.

  3. OSAMU TSUKIMORI, Oct 20, 2021 “Oral drug molnupiravir seen as 'trump card' in Japan's battle against COVID-19” The Japan times

  4. Umair Irfan. Oct 12, 2021, “Why Merck’s Covid-19 pill molnupiravir could be so important” Vox News.

アンカー 10

Vol.30 What You Need to Know about the Covid-19 Vaccine for Kids? 

Last Updated 26 November 2021. Cellspect Co., Ltd.

On October 29, the U.S. Food and Drug Administration authorized the emergency use of the Pfizer-BioNTech COVID-19 Vaccine for children 5 through 11 years of age, a significant step toward making the vaccine available to millions of school-age children.

The FDA advisory panel voted in favor of approval on 26 October, on the basis of clinical-trial data showing that the Pfizer–BioNTech vaccine is about 91% effective at preventing symptomatic SARS-CoV-2 infection in 5- to 11-year olds. Around 4,650 children participated in the trial, receiving two vaccine doses of one-third that of an adult jab, three weeks apart. The committee agreed that children with underlying health conditions, including obesity and chronic diseases like diabetes, would benefit from vaccination. But for otherwise healthy children, the balance wasn’t as clear—given the relatively high proportion of children who might already have immunity from natural infection, as well as the potential risk of myocarditis. In older adolescents and adults, the heart risk was rare but concerning, especially among young males, that’s why the FDA asked Pfizer-BioNTech to provide additional data on more than 1,500 youngsters, in addition to the original 1,500 that the companies originally studied, which allowed the agency to delve more deeply into the side effects.

Encouragingly, for the children tested, the data show that the vaccine is safe in regard to side effects. mRNA vaccines have been linked to a very small risk of myocarditis, an inflammation of the heart muscle, and pericarditis, an inflammation of the lining around the heart, particularly in young men. But there were no reports of either condition in the 5- to 11-year olds involved in the trial, which is a very promising sign. FDA modeling predicted that the number of hospitalizations from myocarditis would generally be fewer than the number of Covid hospitalizations prevented. In its analysis, the FDA noted that people who are naturally infected with COVID-19 have a nearly 16-fold increase in the risk of myocarditis compared to those who are not infected. The scientists also weighed the risk of Multisystem Inflammatory Syndrome (MIS-C), a rare condition that causes fever, loss of blood pressure and damage to different organs including the liver. Over the past year, the CDC recorded more than 5,200 cases of MIS-C and 46 deaths, mostly in children ages 5 to 13 years.

Before the advisory panel’s meeting, an independent FDA review of Pfizer’s data evaluated six fictional US scenarios, with varying levels of virus in the community, and found that, for the most part, the benefits of the vaccine “clearly outweigh the risks”. Officials determined that even if virus levels were very low across the country, the overall benefits of the vaccine would probably still outweigh the potential risks of heart problems, because these conditions typically resolve in a few days after vaccination, unlike COVID-19, which can cause death.


The biggest determinant of how much more sickness and death lies ahead is whether the adolescents get vaccinated, said Dr. Jennifer Nuzzo, an epidemiologist at Johns Hopkins. Although SARS-CoV-2 is not nearly as lethal in younger people as in older ones — around 440 children aged 5 to 18 have died of COVID-19 in the United States, compared with around 724,000 in all age groups, according to the CDC — the combination of kids returning to classrooms and a surge caused by the highly transmissible SARS-CoV-2 Delta variant resulted in a sharp rise in pediatric cases beginning in late July. Of the 6.3 million US children who have tested positive for COVID-19 since the pandemic began, according to an American Academy of Pediatrics report.


According to Johns Hopkins University, global tally of deaths reached 5,000,425 at 4:50 a.m. ET on 1 Nov. "It's another reminder that the Covid-19 pandemic is far from over," Tedros said on Oct 28, noting that the increases in Europe outweigh decreases elsewhere. Japan has been well controlled at present, but the vaccine policy will still be an important issue for further opening up in the future.


  1. Max Kozlov, Oct 27, 2021,“What COVID vaccines for young kids could mean for the pandemic” Nature news

  2. Leah Campbell, Oct 29, 2021, “Everything Parents Need To Know About The Covid-19 Vaccine Trial Results For Kids” Forbes.

  3. Alice Park, Oct 30, 2021, “FDA Authorizes COVID-19 Vaccine for Children 5-11 Years Old” TIME

  4. Samantha Beech, Jake Kwon and Helen Regan. Nov 1, 2021, “Global Covid-19 deaths surpass five million” CNN News.

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