Booster vaccinations in the elderly lead to impaired neutralization of SARS-CoV-2 and atypical B cells Antibodies Coronavirus Disease COVID SARSCoV2 Bcell medrxivpreprint
By Dr. Chinta SidharthanOct 23 2022Reviewed by Benedette Cuffari, M.Sc. In a recent study published on the medRxiv* preprint server, researchers examine neutralizing antibody responses against the severe acute respiratory syndrome coronavirus 2 in individuals aged 70 or above who had received two primary doses of the AZD1222 vaccine, followed by one booster dose of either the BNT162b2 or mRNA-1273 messenger ribonucleic acid vaccine.
A third booster dose has been shown to induce stable spike-protein-specific B-cells that elicit a neutralizing response against SARS-CoV-2 variants with RBD mutations. However, the longevity of B-cell immunity is determined mainly by age. Vaccination-elicited antibody neutralization activity in the serum was measured based on the serum dilution required for 50% infection inhibition . The cutoff for insufficient neutralization was an ID50 value of 20 or less.
Study findings The neutralizing antibodies and both B- and T-cell responses showed no difference across the two age groups after primary vaccination. Moreover, neutralizing antibodies diminished significantly in the six months following the second primary vaccination dose.