The Covid-19 vaccine is both complex and highly anticipated. Today, around 200 projects are estimated around the world. The first question is at what stage are the various vaccines. According to the WHO, 139 are in the preclinical evaluation stage (tested on animals), and at least 27 are in the clinical trials stage (tested in humans). The leading pack is made up of 6 candidates: the last phase of clinical trials, the one to prove the effectiveness of the vaccine, was first reached by the team from the University of Oxford and the AstraZeneca laboratory. Their vaccine is composed of a chimpanzee virus unable to multiply in the human body, to which they have added the genetic code of the Spike protein, characteristic of the coronavirus.

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Pre-orders

Then come three Chinese projects, led by the companies Sinovac and Sinopharm, using inactivated Sars-CoV-2 viruses (responsible for Covid-19). Two other projects, led by the American Moderna and the German-American alliance Pfizer-BioNTech, use a technique never before used: introducing the genetic code of the Spike protein into the body so that it can then produce and learn to recognize this protein. We can also mention the initiative of the Murdoch Children’s Research Institute, in Australia, which spotted that an old vaccine against tuberculosis could have a protective effect against Covid-19 and launched tests on a larger scale.

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The most advanced projects promise results by the end of the year. To meet these impossible deadlines, laboratories do not wait for the final results of one phase to launch the next. Thus, several of them are already in the industrial production phase even before their real effectiveness is known. Governments have decided to place pre-orders to secure manufacturers. The United States launched the Warp Speed ​​program, investing a total of more than $ 9 billion to fund several vaccine projects. The UK has recently joined forces with GSK and Sanofi. France, along with other European countries, also placed an order with AstraZeneca in June. This is one of the objectives of the “Vaccine Committee” which the government set up in July, in addition to the Scientific Council and the Analysis, Research and Expertise (Care) Committee. This group of scientists, chaired by virologist Marie-Paule Kieny, has the particular mission of evaluating the various projects to see the most promising on which to position themselves.

“Emergency”

If the vaccine is, potentially, the lethal weapon against Covid, nothing says that the first finished projects will be the good ones. Indeed, the effectiveness of a vaccine covers many questions. Does it prevent getting sick or does it just reduce symptoms? Does it decrease the transmission of the virus or do people remain contagious? Does it have any side effects? Is it also effective in the elderly? Depending on these responses, the vaccination strategy will be different. You may not get the same vaccine for everyone.

Last point, which is far from being a detail: at the end of phase 3, who must demonstrate that the vaccine provides protection against the targeted disease, marketing authorizations must be obtained in each country. It is now quite possible to have a vaccine developed and authorized in one country, but not in another. Given current diplomatic relations, would Donald Trump buy a Chinese vaccine?

In France, the question also arises. All the more so since it would be detrimental to quickly approve a vaccine only to realize that in use it is ineffective or, worse, dangerous. One of the key elements will be whether or not the epidemic resumes.

“The vaccine will no doubt be used on the basis of an emergency authorization, had warned Marie-Paule Kieny a few days ago. That is the whole message of our committee. We will have to act quickly but cautiously. ” In Switzerland, this untenable position was summed up by a phrase, which has become cult, from Federal Councilor Alain Berset: “Act as quickly as possible, but as slowly as necessary.”


Olivier Monod

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