It is the needle in the hospital foot. This year, the seasonal flu vaccine has less effect, especially among the oldest. One less brake in the middle of the rampant epidemic, therefore, more pressure for health services that are already in total embolism.
The preliminary results published this Wednesday, January 29 by Public Health France (SPF) show a low seasonal flu vaccine efficiency since October 2024: 46% for all risk groups, 62% among children under 65 years of age with affection in the long term and 31% between 65 children of the year and more.
An efficiency measured in the face of all influenza viruses circulating in France. Let us remember, however, that Vaccination coverage in all specific people It is low: 42.9% as of December 31, 2024 and 49.8% between those over 65, less than last year at the same time.
An inappropriate product for virus in circulation
The influenza vaccine has an efficiency that varies from year to year, depending on several factors. The first is the virus to which it is directed, since different flu stumps circulate: A (H1N1), A (H3N2) and B/Victoria.
Vaccines are produced very upstream of the campaign, depending on the strains that circulate the previous season and the recommendations of the World Health Organization (WHO). And in this list established last year, the strain AH3N2 is not taken into account.
“The H3N2 virus that circulates is a bit different from that of the northern hemisphere vaccine,” explains Virologist Bruno Lina to BFMTV. A recipe that cannot be changed along the way.
A less good immune response in the elderly
In addition to the mismatch of vaccines to this epidemic, a recurring problem in the face of a often elusive epidemic, a biological specificity of people over 65 is added.
In this age group, vaccine efficiency is less efficient in particular for those older than 80 due to this “immunosity”, “the quality of the immune response is less good,” Bruno Lina translates.
“The vaccine has a characteristic that is a bit illogical, but therefore, it is nature, it is less effective when you get old, but it is in the elderly that we would like it to be effective,” said doctor Philippe Juvin. BFMTV on January 30.
Second element, the proportion of viruses that circulate is not distributed homogeneously in the population, “the proportion of AH3N2 is more important in the elderly,” says Bruno Lina. However, in this population the vaccine works less well and is less efficient. A double penalty.
This situation further strengthens the interest of double protection: barrier and vaccination gestures. “It is crucial that at the level of the general population the gestures of barrier are systematically adopted because this is really what will allow us to reduce the transmission as quickly as possible and, in particular, the tension in the supply of attention,” explained in mid -January Sibylle Bernard-Steecklin, epidemiologist of the Directorate of Infectious Diseases of SPF.
Source: BFM TV
