Variants, including omicron, fail for at least six months to break through the protection afforded by T cells developed after vaccination.
This happens for all available vaccines.
This is what emerges from a study conducted by researchers from the La Jolla Institute for Immunology in collaboration with the IRCCS San Martino Polyclinic Hospital of Genoa and the University of Genoa and published in the journal Cell.
The study confirmed that T cells recognize all the different variants that emerged in the two years, including Omicron, and remain capable of giving an effective immune response at least 6 months after vaccination.
In detail, by analyzing the T cells of people vaccinated with four different vaccines (Pfizer-BioNTech, Moderna, Johnson & Johnson / Janssen and Novavax), the researchers observed that the reactivity of T cells
at six months is in fact on average 87. -90% compared to the initial post-vaccination one and drops to 84-85% against Omicr
on, regardless of the vaccine received.
"The immunity induced by T cells is therefore long-lasting and significant against all known variants and is not 'pierced' even by Omicron", explains Gilberto Filaci, director of the Biotherapy Unit of the IRCCS San Martino Polyclinic Hospital and one of the authors of study.
"Given the results of the tests 6 months after the vaccine, it is very likely that the T cells of the vaccinated will give rise to long or very long-lasting immune protection against severe disease; however, the booster dose remains very important to further minimize the pur very slight decrease in the T cell response observed six months after vaccination. Finally, it is plausible that the vaccine could also 'hold back' future variants ".