48 coronavirus vaccines are currently being tested for safety and effectiveness in clinical trials in humans. However, according to the WHO, only 11 of these potential vaccines have entered Phase 3 clinical trials, the last step before they get approved for use in humans. Here is an update on these vaccines, which will also probably be the first to reach the market.
Messenger RNA (mRNA) Vaccines
These are currently the most innovative potential vaccines, using highly advanced technology. Our cells are injected with strands of genetic instructions known as messenger RNA to make antigens specific for the coronavirus. These proteins are delivered to the immune system, which then produces antibodies.
The American biotechnology company announced on Monday that its vaccine is 94.5% effective and plans to produce 20 million doses by the end of the year.
The American giant and its German partner BioNTech are preparing to apply to the US Food and Drug Administration for emergency approval of a vaccine that may be available before the end of the year. A few days ago, the companies presented provisional results of phase 3, which showed the effectiveness of more than 90% among the participants.
Vaccines based on inactivated viruses
several vaccines are based on this technology: SARS-Cov-2 infectious agents are chemically or thermally treated to lose their harmfulness while maintaining their ability to trigger an immune response. This is the most traditional form of vaccination.
The Chinese biotechnology company Sinovac has initiated a phase 3 trial with “CoronaVac” in thousands of volunteers, particularly in Brazil.
The Indian company Bharat biotech, for its part, started hiring almost 26,000 people in November for its “COVAXIN” vaccine, developed with the support of the Indian government and will have a vaccine available in the first half of 2021.
Another Chinese laboratory Sinopharm has also initiated two vaccine projects with Chinese research institutes. China plans to have the capacity to produce 610 million doses of several Covid-19 vaccines per year by the end of the year and has already given the green light for the emergency use of some of these vaccines.
Viral Vector-Based Vaccines
Viral Vector-Based Vaccines use another low virulence virus as a carrier, which is transformed to add part of the virus responsible for Covid-19. The modified virus penetrates the cells of the vaccinated people, who then produce a typical SARS-Cov-2 protein and train their immune system to recognize it.
The vaccine developed by the Anglo-Swedish group AstraZeneca and Oxford University uses an adenovirus as a viral vector. The results of the study are expected later this year.
Sputnik V was developed by the Gamalaya Research Center in conjunction with the Russian Ministry of Defense and is based on the use of two viral vectors, two adenoviruses. The Russians announced a few days ago that its effectiveness is 92%. However, the Gamaleïa Institute is accused of violating the usual protocols to accelerate the scientific process. Several Russian officials announced that they had already been vaccinated with Sputnik V.
Johnson & Johnson
The US-based company has started two clinical trials for its modified adenovirus vaccine candidate, one trial with a single dose and the other with two doses. A total of 90,000 participants will participate worldwide. Results are expected in the first quarter of 2021.
The Chinese company developed the adenovirus vaccine “Ad5-nCoV” together with the military. Phase 3 trials are being initiated in Mexico, Russia, and Pakistan.
A Recombinant nanoparticle vaccine
The American biotechnology company Novavax is developing a recombinant nanoparticle vaccine. SARS-Cov-2 has spikes on its surface that come into contact with the cells to be infected. These proteins can be replicated by the cells and by exposing the immune system to them antibodies are generated. In September, Novavax started its Phase 3 trial in the United Kingdom and a trial in the United States is scheduled for the end of November.