Darkest hour just before dawn: a quick guide of current COVID-19 vaccines in use
Last Updated 15 January, 2021. Cellspect Co., Ltd.
Although the New Year has just begun, COVID-19 daily deaths record faster than at any point in 2020. Globally, the total confirmed cases of Covid-19 have reached over 91,717,000 with over 1,965,000 deaths. The U.S. daily COVID-19 death toll reaches a record-high number of 4,327 on Jan. 12. On the same day, Japan government also expands its second state of emergency to 11 prefectures and suspends entry of all foreigners.
While those "awful" numbers will likely continue this winter, better days are coming, said Dr. Paul Offit, a member of the US FDA Vaccines Committee. Mass vaccinations and warmer weather could lead to a "dramatically better" summer, Dr. Paul Offit said. Dozens of coronavirus vaccines entered clinical trials during 2020, and now, a handful have been authorized for emergency use in various countries — meaning the shots can be administered to the public while their developers continue to collect data on their safety and efficacy. Here's a quick guide to the COVID-19 vaccines now in use around the world.
The Pfizer -BioNTech vaccine is administered in two doses, given three weeks apart and is reported 95% effective at preventing COVID-19. It must be stored at -70 ℃. Several other countries have also authorized the vaccine for emergency use, including the U.K., Argentina, Chile and Singapore, and the European Union. Bahrain, Canada, Saudi Arabia and Switzerland have fully approved the vaccine. The vaccine bases on mRNA coding for the coronavirus spike protein, a structure that sticks off the virus's surface and is used to infect human cells. Once inside the body, the vaccine instructs human cells to build this protein, and the immune system learns to recognize and attack it.
The vaccine developed by U.S. biotech company Moderna also uses mRNA as its base and is estimated to be 94.5% effective at preventing COVID-19. Like the Pfizer-BioNTech vaccine, it's delivered in two doses, but the doses are given four weeks apart, rather than three. Another difference is that the Moderna vaccine can be stored at at -20℃. The FDA authorized the Moderna vaccine for emergency use in Dec. and Israel and the European Union both authorized the shots for emergency use in Jan. Canada fully approved the vaccine on Dec. 23.
According to early analyses Oxford-AstraZeneca vaccine, in people given two full-size doses, spaced 28 days apart, the vaccine was about 62% effective; in those given a half-dose followed by a full dose, the vaccine was 90% effective. The U.K. and Argentina authorized the Oxford-AstraZeneca vaccine for emergency use in late December, and India and Mexico authorized the vaccine for emergency use in January. The shots contain a weakened version of adenovirus, a common cold virus that naturally infects chimpanzees. Scientists modified the virus so it cannot replicate in human cells and then added genes that code for the coronavirus spike protein. Inside the body, the vaccine enters cells and delivers these spike protein genes, which the cells use to build the spike protein itself. The presence of spike proteins triggers an immune response.
Sinopharm (Beijing Institute of Biological Products)
Sinopharm, the state-owned China National Pharmaceutical Group, and the Beijing Institute of Biological Products developed a vaccine from an inactivated coronavirus, meaning a modified version of SARS-CoV-2 that cannot replicate. In late December, Sinopharm announced that the vaccine, called BBIBP-CorV, is more than 79% effective. The United Arab Emirates authorized BBIBP-CorV for emergency use in September and then fully approved the vaccine in December. Bahrain and China also fully approved the vaccine in December, and Egypt authorized it for emergency use in January. The vaccine is given in two doses spaced three weeks apart.
Sinopharm (Wuhan Institute of Biological Products)
Sinopharm's second vaccine candidate, developed by the Wuhan Institute of Biological Products, also uses an inactivated coronavirus as its base. The vaccine has been authorized for emergency use in China and the U.A.E., but little is known about its efficacy.
CanSino Biologics, in collaboration with the Beijing Institute of Biotechnology, developed a COVID-19 vaccine using a weakened adenovirus, but one that naturally infects humans, not chimpanzees. Late-stage clinical trials with the vaccine are still ongoing, and its efficacy is not yet known. The shot is given in a single dose. In June 2020, the CanSino vaccine was given approval to be used by China's military.
The Chinese company Sinovac Biotech developed a vaccine from an inactivated version of SARS-CoV-2. The vaccine, called CoronaVac, is given in two doses 14 days apart. China authorized the vaccine for emergency use in July. One clinical trial in Brazil suggested that the vaccine was about 78% effective in one small subgroup of patients, but across all people, the efficacy may be closer to 63%, according to Estadão, a Brazilian news outlet.
The Indian company Bharat Biotech, along with the Indian Council of Medical Research and the National Institute of Virology developed a vaccine from an inactivated coronavirus, called Covaxin. The vaccine is given in two doses, spaced four weeks apart, and has been authorized for emergency use in India. Its efficacy has not been publicly reported.
Gamaleya Research Institute
The Russia Ministry of Health's Gamaleya Research Institute developed a coronavirus vaccine candidate called Sputnik V. The vaccine contains two common cold viruses, or adenoviruses, that have been modified so they don't replicate in humans; the modified viruses also contain genes that code for the coronavirus's spike protein. Russia announced that the vaccine is more than 91.4% effective in preventing COVID-19, according to early data from clinical trials. (Full details of the trials have yet to be published in a scientific journal.) Russia had already approved the vaccine for limited use in August and since November, Belarus, Argentina and Serbia have also authorized the vaccine for emergency use.
In October 2020, Russia granted "regulatory approval" to a second vaccine, one developed by the Vector Institute, a Russian biological research center, according to CNBC. The vaccine contains coronavirus peptides, which are small portions of proteins found in the virus. Like Sputnik V, the vaccine earned approval in Russia before large-scale clinical trials had been conducted. As of now, its efficacy is still unknown.
The biggest vaccination campaign in history has begun. More than 32.4 million doses in 45 countries have been administered, according to data collected by Bloomberg. Delivering billions more will be one of the greatest logistical challenges ever undertaken.
Nicoletta Lanese. 13 Jan 2021. “Quick guide: COVID-19 vaccines in use and how they work” Live Science News.
Christina Maxouris and Holly Yan. 13 Jan 2021. “The US just suffered its worst day ever for Covid-19 deaths. But this summer could be 'dramatically better'” CNN News.
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