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Less than a year after the emergence of the novel coronavirus, American pharmaceutical group Pfizer and its German partner BioNTech filed an application for authorization of their vaccine in Europe on Tuesday. This Wednesday, the UK government announces that it will authorize the vaccine on its territory and launch the “next week” campaign.
An unprecedented speed of development in vaccine history that raises concerns. Especially as regards France, Emmanuel Macron has already announced that the vaccination campaign could start “from the end of December or the beginning of January”.
A topic often comes up on Facebook: how did we manage to develop not one, but several vaccines against Covid-19 in such a short time, when there are still none for AIDS, 37 years after the discovery of the virus? For many internet users, this reasoning is proof that future Covid-19 vaccines cannot be reliable, some even going so far as to liken the future vaccination of the population to “collective suicide”.
But there are actually several reasons for developing the Covid-19 vaccine in record time, while researchers are still looking for an AIDS vaccine.
Two very different viruses
The two viruses have very different structures. If they are both RNA (ribonucleic acid) viruses, HIV, the AIDS virus, is also a retrovirus. This means that it integrates into the DNA of infected cells, causing them to multiply and become undetectable by the immune system. HIV therefore remains in the body indefinitely.
Furthermore, HIV, which has several subtypes, mutates so quickly that by the time the body produces antibodies, they are already obsolete and can no longer neutralize the virus. These constant mutations are what make it difficult “to produce a vaccine against the right target,” explains Nathan Clumeck, professor of infectious diseases at the Free University of Brussels.
On the contrary, “Covid-19 has a simpler structure, with a door lock which does not mutate in order to escape the antibodies that the infected host will produce ”, continues the infectious disease specialist. This is why antibodies work effectively against this virus. Therefore, patients spontaneously recover from Covid-19 in the vast majority of cases. However, you can “easily develop a vaccine when you have a disease that cures by reproducing what nature does,” explains Jean-Daniel Lelièvre, head of the infectious disease service at the Henri-Mondor hospital in Créteil. Conversely, HIV cannot be eliminated naturally by the immune system.
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Additionally, SARS-CoV 2 has genetic similarities to SARS-CoV, the virus responsible for the SARS epidemic fifteen years ago. “We had accumulated a lot of data on this virus. We knew that the antibodies protected ”, continues the expert of the High Authority for Health, which is preparing the arrival of vaccines against Covid-19 in France. This knowledge made it easier to develop a vaccine against the new coronavirus.
Although several tests have been conducted on AIDS vaccines, they have only led to modest results and to date there is still no effective vaccine against this disease. However, it is possible to take a combination of drugs, called triple therapy, to reduce the multiplication of the virus in the body as much as possible.
Technological advances
Furthermore, since the discovery of the AIDS virus in 1983, significant technological advances have been made. The sequencing of a virus, for example, which allows us to know its genetic heritage to better neutralize it, was carried out in record time for Covid-19. Three days were enough for the researchers of the Institut Pasteur to completely sequence its genome, compared to several years for that of HIV.
The pandemic has led laboratories to refine existing technologies to produce new vaccines against Covid-19. This is for example the case with messenger RNA. Used in particular in Pfizer and Moderna products, it is intended to tell cells which proteins they need to synthesize to fight the virus.
“We have used messenger RNA against HIV, Ebola, Zika, we have been using it for 10 years”, says Professor Lelièvre. Today we are reaching the maturity of this technology, and it is the ideal time to use it on a virus not very different from others that we know well. This method has proven to be easy to manufacture and very effective.
Technological improvements that “will certainly be tested for HIV” although it is “still too early to say whether they will be effective on this virus,” notes Olivier Schwartz, head of the Virus and Immunity unit at the Institut Pasteur.
Global mobilization
Finally, the Covid-19 epidemic, which has rapidly become a pandemic, “has accelerated the response of research institutes and laboratories around the world while always respecting health and safety protocols,” continues Olivier Schwartz. The Ebola virus had already enabled scientists to demonstrate that clinical trials progress can be faster, without “calling into question the evaluation of a vaccine’s effectiveness and its tolerance”, Professor Lelièvre abounds.
Many states, as well as private laboratories, have financially supported manufacturers in developing their vaccine candidate. ‘Thanks to their knowledge of previous SARS-CoV2-like viruses, the manufacturers had a good basis for believing that their vaccines would be effective,’ says Professor Lelièvre. In particular, this has prompted companies to start vaccine production chains even before they have the full results of their clinical trials. The research and production phase of a vaccine had never been conducted simultaneously, companies usually awaiting a marketing authorization (MA).
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“The producers have argued with the various states, for example the European Union, forcing them, if they order the vaccine, to pay the doses, even if in the end it doesn’t work. The challenge was to make it work, ”continues Professor Lelièvre.
Even in terms of administrative procedures, everything has been speeded up. Covid vaccine files were treated as a priority whenever preliminary results were provided. The ANSM, the National Agency for the Safety of Medicines, for example, has asked its experts to devote themselves exclusively to practices related to Covid-19.
Numerous emergency procedures have also been initiated. The US Medicines Agency is reviewing applications for emergency use authorization for Pfizer / BioNTech and Moderna products. If approved, a vaccination campaign could also be launched there before the end of the year holidays in the United States.
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