Le Matin – Covid-19: 11 vaccine candidates in final phase of human trials

Faced with Covid-19, 48 vaccine candidates are currently in clinical trials on humans. But only 11 have entered phase 3, the last before approval from the authorities, according to the World Health Organization. Update on these candidates likely to arrive on the market first.

At present, it is the potential vaccines that appear to be the most advanced, using ultra-innovative technology. It consists of injecting into our cells strands of genetic instructions called messenger RNA, to make them manufacture specific proteins or “antigens” of the coronavirus. These proteins will be delivered to the immune system, which will then produce antibodies.

  • Pfizer: the American giant and its German partner BioNTech recently presented results from phase 3 showing an efficacy of their vaccine candidate of 95% among participants. They asked the US Drug Administration (FDA) on Friday to authorize their vaccine, the first manufacturers to do so in the United States or Europe.
  • Modern: The American biotechnology company announced that its vaccine was 94.5% effective, it plans to manufacture 20 million doses by the end of the year.
  • Several vaccines rely on this technology: the infectious agents of SARS-CoV-2 are treated chemically or by heat to lose their harmfulness, while retaining their ability to provoke an immune response. It is the most traditional form of vaccination.
  • Sinovac: Chinese biotech has launched a phase 3 trial for “CoronaVac” on thousands of volunteers, particularly in Brazil.
  • Sinopharm, another Chinese laboratory, has launched two vaccine projects with Chinese research institutes. China plans to be in capacity by the end of the year to produce 610 million doses per year of several Covid-19 vaccines, and has already given the green light to emergency use of some of them.
  • Indian society Bharat Biotech launched in November the recruitment of nearly 26,000 people for its “COVAXIN” developed with the support of the Indian government, and relies on a vaccine available in the first half of 2021.

The “viral vector” vaccines use another weakly virulent virus as a carrier, transformed to add part of the virus responsible for Covid-19. The modified virus enters the cells of vaccinated people, which then make a protein typical of SARS-CoV-2, training their immune system to recognize it.

  • AstraZeneca, an Anglo-Swedish group, and the University of Oxford: their vaccine uses an adenovirus as a viral vector. According to interim results published on Monday, it is 70% effective on average, and even 90% in some cases. AstraZeneca says it is moving quickly towards the planned manufacture of three billion doses, which will be available in 2021.
  • Johnson & Johnson: the American has launched two clinical trials of its candidate composed of a modified adenovirus, one single-dose, the other over two doses. Around the world, 90,000 participants will take part in total. Results expected in the first quarter of 2021.
  • CanSino Biological: the Chinese company has developed “Ad5-nCoV”, together with the army, an adenovirus-based vaccine. Phase 3 trials are launched in Mexico, Russia and Pakistan.
  • Spoutnik V: developed by the Gamaleïa Epidemiology Research Center, with the Russian Defense Ministry, it is based on the use of two viral vectors, two adenoviruses. The Russians announced a 92% efficiency a few days ago. However, the Gamaleïa Institute is accused of breaking with the usual protocols to accelerate the scientific process. Several senior Russian officials announced that they had already been vaccinated with Sputnik V.
  • Novavax: American biotech is developing a so-called “subunit” recombinant vaccine. The coronavirus has spikes (viral proteins) on its surface to come into contact with the cells to be infected. These proteins can be reproduced and then presented to the immune system to make it react. Novavax launched its phase 3 trial in the United Kingdom in September, and is due to start a trial in the United States at the end of November. Preliminary data is expected in the first quarter of 2021.

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