US health authorities said on Tuesday that the effectiveness of the Pfizer and Moderna vaccines fell to 66% against the Delta variant of the coronavirus. For epidemiologist Martin Blachier, guest on CNEWS, this means that collective immunity may not be achieved.
“66% is not very important. It shows that collective immunity, which we have been talking about for a very long time, is almost unattainable, ”explained the specialist this Wednesday morning in the Hour of the Pros.
Remember, collective immunity corresponds to the percentage of the population immunized or protected against infections from which the virus will no longer be able to spread. When the population is sufficiently immunized (because it is already infected or thanks to the vaccine), the virus is brought to disappear, since it can no longer infect new people. The government’s strategy is therefore based on vaccinating as many people as possible, to achieve collective immunity quickly, and thus put an end to the epidemic.
Vaccinate people at risk as a priority
However, US health officials reported that messenger RNA vaccines, Pfizer and Moderna, were only 66% effective against Delta variant infections, while the rate rose to 91% when this variant was not. not predominant. Martin Blachier nevertheless recalls an essential point: “it is an efficiency on the transmission of the virus. It is absolutely not the effectiveness of the protection against the disease. “
This means that the vaccines are less effective in stopping the transmission of the virus, but are still very effective in fighting severe forms of Covid-19. “The idea that everyone should be vaccinated and that the viral circulation will disappear with this vaccine is getting farther and farther away. But the idea is rather to vaccinate everyone so that there are a minimum of people who arrive at the hospital. ”
According to Martin Blachier, there is therefore no urgent need to vaccinate children. The important thing is to continue to focus on the populations that are most likely to develop severe forms of the disease so that the intensive care services are not again saturated. The High Authority of Health (HAS) published this Tuesday an opinion in this direction, recommending a third dose of vaccine for those over 65 years old.