Encouraging preliminary results for a Covid-19 vaccine

• An experimental US vaccine elicited an immune response in eight healthy volunteers.
• The vaccine appears to be able to prevent Covid-19 from replicating in mice.
• A phase 2 clinical trial of 600 people in June should provide more certainty.

If the world's stock markets soar on Monday, it is largely because of this announcement. US biotech company Moderna has released very preliminary but encouraging results for its experimental coronavirus vaccine in eight volunteers, before large-scale trials planned for July. Be careful, however, if the experimental vaccine did provoke an immune response in eight healthy people, there is no evidence, as yet, that it is capable of neutralizing Covid-19.

Summary of our SARS-CoV-2 #vaccine (mRNA-1273) interim Phase 1 data. Read more: https://t.co/aIq34ullAh #mRNA pic.twitter.com/BVbYuWTkOy

Encouraging but very preliminary results

The young company, in which the US government has invested $ 483 million, has announced "positive interim data" from the initial phase of clinical trials: in eight people, the vaccine project called mRNA-1273 has triggered a similar immune response to what we see in people who have been naturally infected with the virus that causes Covid-19. This first phase also aimed to verify that the vaccine is not toxic, and Moderna only reported a few side effects such as redness at the injection site.

This is currently a press release, and the results have not yet been screened by pairs. The first eight volunteers (out of 45) were healthy people aged 18 to 55. Does the antibody concentration reach the minimum levels required by health authorities for a vaccine? Are these antibodies effective in neutralizing Covid-19? We don't know yet. Moderna says however tests conducted on mice have separately shown that the vaccine prevented the virus from replicating in their lungs.

We must establish regulatory measures for antibody titers, clinical measures of benefit, to serve as clear benchmarks of success for studies. Right now FDA requires neutralizing antibody titer of at least 1: 160 for convalescent serum donors. Is that the level for a vaccine? 2 / x

Phase 2 of 600 people in June

The full results of the phase 1 trial, on 45 participants, are not yet known. Phase 2, out of 600 people, has already received the green light from the American Medicines Agency (FDA) and should start by June. Phase 3, with even more participants, is slated to begin in July, said Stephen Hoge, president of Moderna.

The vaccine was developed in partnership with the National Institute of Infectious Diseases (NIAID), led by Dr. Anthony Fauci. The institute is also conducting the clinical trial. The first data "suggest to us that mRNA-1273 has a high probability of creating protection" against the coronavirus, welcomed in a conference call Stéphane Bancel, the French general manager of Moderna. "We are overwhelmed by these interim data," he said.

Billions of doses needed

The company, founded nine years ago and based in Cambridge near Boston, has so far never received a drug or vaccine license. In the process, Moderna's New York share price was up 26% at midday.

Many governments and laboratories want one or more vaccines next year, or even before the end of 2020 for emergency vaccinations. The problem is not only to identify an effective and safe vaccine, it will then be necessary to manufacture billions of doses, and distribute them in an order that remains to be negotiated.

Large laboratories, as well as Moderna, have announced that they would start producing millions of doses without waiting for the results of clinical trials, an unprecedented risk-taking and largely funded by states and large non-governmental organizations. The company recently announced a partnership with the giant Lonza to manufacture up to a billion doses per year.

Health

Sanofi affair: Does France still have a chance in the race for the Covid-19 vaccine?

Health

Coronavirus: A vaccine available within a year, an "optimistic" scenario, according to the European Medicines Agency

• Coronavirus
• Health
• Covid 19
• Vaccine