Booster doses of the COVID vaccine are spreading in many developed countries beyond the 65+ age bracket. Belgium will inoculate the entire adult population. Italy, those over 40. Japan, over 18, the same as the US raises with the recent request for authorization from Pfizer. In France it is committed to extending it from the age of 50. Will the third (dose) be the charm or are we doomed to an annual vaccination? There is no unanimity among the experts, who in any case suggest that this question will be resolved in the future, not now.
The “real life & rdquor; on the effectiveness of booster doses in the population are becoming available thanks to countries like Israel, which by virtue of its agreement with Pfizer studies the effects of vaccination in detail and transparency. The Israeli Ministry of Health (see graph) notes that booster doses increase effectiveness against infection to a level greater than 90%. On the other hand, in those individuals with two doses but without booster, the effectiveness against contagion has been reduced to between 48% and 71%.
Scientists agree on the benefits of the vaccine and the risk of rejecting it. The unvaccinated, who make up 5% of the Spanish population, occupy 70% of the ICU beds due to COVID. They have a 45 times higher risk of hospitalization. It is also known that the protection conferred by this vaccine does not last for life and that it diminishes after about 6 months.
The famous American immunologist Anthony Fauci said in September that “the optimal regimen & rdquor; for mRNA vaccines “it will include that third booster injection & rdquor ;, although he was of the opinion that an annual prick will probably not be necessary.
The SARS-CoV-2 virus mutates much less than the seasonal flu virus, which requires an annual update to include new strains. However, experts such as the American immunologist Anthony Leonardi, a T-cell specialist, believe that we will have to immunize ourselves year after year. “There will be a waning protection, certainly for mild and moderate illness and possibly even severe illness. So people are going to need to get vaccinated at least once a year, I think & rdquor ;, he told wsws.org.
In a recent article in the “New England Journal of Medicine,” Dr. Arnold S. Monto, epidemiologist and member of the vaccine committee of the US drug agency (FDA), reasons that, although influenza and COVID are very different viruses and SARS-CoV-2 mutates much less, “revaccination will be necessary for the same reasons that revaccination against influenza is necessary: antigenic variation and reduced immunity & rdquor ;. He adds that “protection is relatively short even after a natural infection & rdquor ;, and warns that“ it will be necessary to determine the frequency and consequences of revaccination & rdquor ;.
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On natural infection, the CSIC virologist Margarita del Val He pointed out yesterday that “all people are going to be infected sooner or later by COVID-19 & rdquor ;, but that in those vaccinated” it will mean a reinforcement of immunity & rdquor ;. The infection, he said, “can refresh and expand immune memory, releasing more of the virus’s 25 proteins to the body. [más allá de la S en la que están basadas las vacunas]& rdquor ;, so “we will be protected for a longer time and shielded from the variations that may arise & rdquor ;.
One hope in this uncertainty will be new vaccines, such as those based on proteins, for which there is little data on the duration of immunity they confer. This is the case of the Novavax vaccine, whose antigen is manufactured by Zendal in Porriño.
Reference-www.elperiodico.com