| Abstrakt: |
Healthcare workers who had received the BNT162b2 vaccine were tested monthly for anti-spike IgG and neutralising antibodies in this prospective 6-month study to assess the vaccine's longevity of protection against COVID-19; there were 4868 participants studied including 3808 analysed in a linear mixed-model. There was a consistent decline in IgG antibody level over time, while neutralising antibody levels decreased more rapidly during the first 3 months followed by a relatively slow decrease. IgG antibody levels correlated well with neutralising antibody titres, but the regression relationship between the IgG and neutralising antibody levels was dependent on time since the second vaccine dose was administered. Neutralising antibody titres 6 months after the second dose were lower among: i) men versus women (ratio of means, 0.64 [95% CI 0.55, 0.75]); ii) individuals aged ≥65 vs. 18--<45 years (0.58 [0.48, 0.70]); and iii) participants with versus without immunosuppression (0.30 [0.20, 0.46]). [ABSTRACT FROM AUTHOR] |
