Omicron variant and Pfizer vaccine: reduced protection, very first data

Indications from a study conducted in South Africa

The Pfizer vaccine, with the two standard doses, may be less effective against the Omicron variant of covid. While scientists from numerous countries are working to outline the identikit of the variant – between symptoms and contagiousness – the indication linked to the first data of a small study conducted in South Africa by the Africa Health Research Institute arrives. The researchers, based on data published online and not yet peer-reviewed, have highlighted a “clear reduction” in the protection offered by the vaccine against the variant.

Some elements of the study were summarized on Twitter by South African virologist Alex Sigal, one of the signatories of the research. The analysis, says the scientist himself, is still in progress: so far data have been collected on 12 subjects who received the Pfizer vaccine in the ordinary cycle and without the booster dose. The results of the study could change with the acquisition of further data, in the general framework characterized by the research activity carried out in numerous countries and also by vaccine manufacturers.

“I would tend to be more optimistic,” Ugur Sahin, founder of Biontech (partner of Pfizer), told Nbc.. In addition, the study noted that the combination between recovery from covid and administration of the vaccine “increases the level of protection” in particular from severe disease.

Symptoms related to the Omicron variant are one of the topics touched in Washington by Professor Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, during a virtual briefing at the White House. “When we consider transmissibility, we have evidence at the molecular level: it suggests that the mutations identified in Omicron and other variants suggest increased contagiousness. The data is accumulated rapidly, on a daily basis, to allow us to determine the increase in numbers. cases “and hypothesize” Omicron’s rapid replacement of the Delta variant in certain situations, “says the immunologist.

The data comes mainly from South Africa: “On the basis of the cases, there does not appear to be a very serious disease“, but” an increased tendency to reinfection “should be monitored for subjects previously infected with the Beta variant or the Delta variant.” Since the data on the severity of the disease, hospitalizations and deaths are not immediate, it will take at least two weeks before get an overview of the situation and then more time for an even more detailed picture. So, I would say we shouldn’t draw firm conclusions, certainly not before the next two weeks. “