Covid: what is reactive vaccination, this new strategy studied in the face of the epidemic? – Free lunch

In a context where the Covid epidemic continues to progress and where restrictive measures have been eased, vaccination remains the government’s main tool in the fight against the virus and its serious forms. Researchers from Inserm and the University of the Sorbonne have looked into a strategy to further increase the vaccination rate in the population. Researchers from Inserm and the Sorbonne University have published a study modeling a strategy to encourage even more vaccination against Covid in the population. This strategy has a name: reactive vaccination. The French population is widely vaccinated. As of March 22, Public Health France indicates that 79.4% of the population has a complete vaccination schedule and that 80.8% has received at least one dose. However, contamination continues to increase, in a context of easing of restrictive measures. So, faced with a virus that is still circulating strongly and faced with more contagious variants, researchers are thinking about ways to continue to encourage vaccination, a strategy on which the government is essentially basing itself to fight against the most serious forms of Covid in particular. . What does this strategy consist of? And reactive vaccination is one of them. The study carried out by Inserm researchers was published on March 17 in the journal Nature Communications. Their results show that “in most scenarios, with the same number of vaccine doses, a reactive strategy is more effective than other vaccination strategies in reducing the number of Covid-19 cases”, summarizes the press release. ‘institute. So what is this strategy? It actually involves the vaccination of “the whole entourage of the cases in the home and the place of work or schooling”. This strategy has already been used in other contexts, notes Inserm, in particular to deal with waves of meningitis. This vaccination strategy is therefore opposed to a massive vaccination strategy, since it targets more the entourage of a person who has been infected with the virus. And the results of the study show that this strategy is all the more effective if the vaccination coverage is lower. When is the strategy relevant? By way of comparison, according to the projections made, “in a context where vaccination coverage is around 45% and where viral circulation is high, the reduction in the number of cases over a period of two months goes from 10 to 16% “, with reactive vaccination, compared to a mass vaccination strategy. On the other hand, if the vaccination coverage is higher, the strategy is of less interest, since consequently, the entourage of the infected person has a high chance of already being vaccinated. Inserm specifies that this approach could make it possible “to reach people who have not yet been vaccinated and to convince them more easily of the usefulness of the vaccine”. Another projection, it “is a tool that can also be reused and adapted in France in the event that another variant emerges and where it is necessary to test the effectiveness of a reactive strategy to administer possible booster doses. “, says Chiara Poletto, Inserm researcher and last author of the study.