The news Covid-19 vaccination campaign begins this October 15 in metropolitan and overseas France, and began on September 10 in Mayotte. From the very first report of the coronavirus to the World Health Organization (WHO) in December 2019 to the first vaccinations in France in December 2020, barely 12 months have passed. These vaccines designed in record time have raised many questions that Science and Future has continued to bring to researchers and doctors in a context of controversy and vaccine distrust. Here is an overview of what our editorial team has produced on the Covid vaccination and what we need to remember before going to give his injection.
Why get vaccinated?
The virus is still circulating and revealing itself still dangerous for the most fragile among us ; it remains strongly recommended for those aged 65 and over, people with immunodeficiencies, people with comorbidities, THE pregnant women and all those who work with at-risk populations. The virus is experiencing several periods of resurgence, even in the depths of summer unlike the flu and colds, which circulate all the more easily when we are forced to stay indoors by the cold. The protection provided by a vaccine is effective at the individual level, but it also aims to stop the spread of the disease at the level of an entire population. The virus's path is hampered if it can no longer spread from one immune organism to another. As early as 2021, a study of the impact of the very first vaccination campaigns confirmed that they had very probably helped prevent nearly 50,000 deaths in FranceIn January 2024, the WHO regional head estimated that at least 1.4 million lives in Europe saved by vaccines. In 2023, virologist Etienne Simon-Loriere explained to Science and Future that " Covid-19 remains a kind of lottery since some, even in good health, unfortunately develop severe forms". For each new variant that threatens the most fragile and the immunocompromised, caution remains required. These are the people who are urged to have a booster shot of the Covid-19 vaccine during each vaccination campaign.
How do the anti-Covid vaccines selected by France work?
All vaccines have the following aim to stimulate the immune system to help it recognize the incursion of a virus and confront it. This stimulation takes the form of a simulation: the vaccine behaves like a virus, which the body will learn to recognize and combat. The way in which this decoy role is taken on is different from one vaccine to another.
The Covid vaccines that ended up to impose oneself in France, and which will be proposed during the fall-winter 2024-2025 campaign are the messenger RNA vaccines (for messenger ribonucleic acid or mRNA). When it comes time to purchase, the question arises for health authorities:efficiencyThey are moving very quickly towards the first vaccines. counterparts announcing 95% of efficacy for that of the Pfizer laboratory, 94.5% for that of Moderna.
This technology was developed in the 1990s but was first tested during this pandemic. Instead of delivering an attenuated or inactivated virus into the body, they deliver an mRNA of the SARS-CoV-2 virus, the one that is capable of manufacturing the Spike protein present on the surface of the virus SARS-CoV-2. The mRNA strand degrades once its message is delivered to the immune system, which is then able to recognize a Spike protein. A recent variation of this technique consists of allowing this mRNA to to fold back and to strengthen the human immune response. These are the vaccines that have finally become established in France and come from the Moderna laboratories and BioNTech-Pfizer.
The other, more classic technique, present in other vaccines offered to the French is that of the viral vector vaccine, an adenovirus. This is the case of that of theOxford University and AstraZeneca, the Vaxzevria, withdrawn from sale in 2024 due to lack of demand, while it was one of the first to be put on the market during the pandemic. It has experienced some setbacks and a lot of distrust from different audiences. However, it has played an effective protective role against Covid-19.
Vaccines that were forgotten or never crossed the finish line
- Do we remember the reluctance of the Western world towards Sputnik-V ? The Russian vaccine has proven its effectiveness but its reputation is tarnished by Russia's political aura in Europe and the United States.
- Vaccines Janssen And Nuvaxovid from american Novavax based on more traditional technologies do not provide the same guarantees of protection. By proposing them, while the AstraZeneca vaccine was causing concern, the French authorities hoped to convince those who were afraid of RNA vaccines.
- There will have been no “made in France” vaccine. There will not be any vaccines “made in France”.Pasteur Institute had to abandon its vaccine in January 2021, deemed less effective than an mRNA vaccine. And that of the laboratory Sanofi, will have been abandoned in the face of competitors who are already well established economically.
- CureVac, developed by a pioneering German start-up with mRNA technology, would not require very low storage temperatures unlike the vaccines from Moderna and BioNTech. It would have been perfectly suitable for developing countries. But not very effective in keeping up with the competition.
Why do we need so many Covid-19 booster shots?
Vaccine boosters or boosters given 6 to 3 months after the primary vaccination (which itself required several injections) contrast with the injection protocols of other vaccines such as those targeting measles, mumps and rubella for example, and valid for life.
The arrival of new variants – Omicron for example – raises questions about the effectiveness of vaccines that were formulated before the emergence of later variants. Studies on animal models tend to prove the effectiveness of booster doses, regardless of the brand of serum. Each booster increases the level of antibodies and their quality, it generates a wider range of antibodies even more capable of recognizing variants of the virus. In patients at higher risk because they have cancer or are immunocompromised, The recall should occur much more frequently to stimulate this production of antibodies.
What about side effects?
Side effects have been at the heart of the debates on vaccines in France. Faced with new vaccines, designed in record time, the population's suspicion was legitimate. Three years later, What conclusions can we draw? Onnearly 157 million doses of all vaccines combined in France"50,000 side effects considered serious have been reported to the National Agency for the Safety of Medicines and Health Products. This corresponds to " a reporting rate of 0.03 % ". Among these notable side effects, the thrombosis have left a strong impression. These very rare cases of unusual blood clots, combined with a lower efficacy of these adenoviral vector vaccines (Janssen and AstraZeneca) have led the authorities to abandon them. The mRNA vaccines, the most administered in France, have also had their share of reports; among the most serious cases, there are inflammations of the heart muscle ( Myocarditis and pericarditis), high blood pressure and heavy menstrual bleeding but no cardiovascular risk or risk of Gillain-Barre syndrome additional.
In the land of vaccine skepticism
The Covid-19 epidemic in France will have been marked by a concomitant surge...of Vaccinoscepticism. Vaccine defiance is old At Pasteur country. Several previous events have built the population's distrust of anti-Covid vaccines: controversy surrounding the vaccine againsthepatitis B, failed political management of the H1N1 flu pandemic, Mediator crisis. For an overseas territory like Martinique, vaccine hesitancy is also motivated by the island's colonial past and health scandals such as chlordecone. Added to this are recurring objections on adjuvants or the influence of overly greedy pharmaceutical industries. At the time when the pandemic was in full swing, in the fall of 2020, just over one in two French people agreed to be vaccinated while the world average was rather around 75% according to an Ipsos survey. Convincing a majority of French people to get vaccinated was therefore not not won.
Covid and flu, same vaccine fight?
Winter vaccination campaigns are trying to simultaneously stop seasonal flu and endemic Covid, which circulates continuously within the population. Double vaccination that can be carried out on the same day will make it possible to avoid the concomitance of these epidemic waves during the winter which exert pressure on the functioning of the French health system. The day will come when a combined vaccine against the two diseases will be administered. The Moderna laboratory is awaiting marketing authorization for a vaccine of this type (2024).
Unlike the others acute respiratory infections Like influenza and bronchiolitis, which mainly experience winter peaks, the Covid-19 virus experiences several intense epidemic waves over the course of a year. It progresses from July onwards, and seems culminate in September and December. Covid-19 is not yet a seasonal virus like the common cold.
What impact will the anti-Covid-19 vaccination have had in France?
There was an unmistakable before/after for analysts from Santé publique France who are looking at the incidence rates of the disease, and even more so if we focus on the different age groups. The oldest, who were the initial targets of the vaccination campaign, are the first to see their numbers decrease in terms of hospitalizations. One year after the very first campaign began in December 2020, 75% of the French population was fully vaccinated, with the two doses required for a primary vaccination. As of 1Er January 2023, vaccination coverage (complete initial vaccination schedule) in France is estimated at around 80% of the French population.
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