Abstract
Purpose: As protection from COVID-19 following two doses of the BNT162b2 vaccine showed a time dependent waning, a third (booster) dose was administrated. This study aims to compare the antibody response following the third dose versus the second and to evaluate post-booster seroconversion.
Methods: A prospective observational study conducted in Maccabi Healthcare Services. Serial SARS-CoV-2 Spike IgG tests, 1,2,3 and 6 months following the second vaccine dose and one month following the third were obtained. Neutralizing antibody levels were measured in a subset of participants. Per individual SARS-CoV-2 Spike IgG titer ratios were calculated one month after the booster administration compared to titers one month following the second dose and prior to booster.
Results: Among 110 participants,56 (51%) were women. Mean age was 61.7 ± 1.9 years and 66 (60%) were immunocompromised. One month after third dose, IgG titers were induced 7.83 (95 %CI 5.25-11.67) folds and 2.40 (95 %CI 1.90-3.03) folds compared to one month after the second, in the immunocompromised and immunocompetent groups, respectively. Of the 17 immunocompromised participants who were seronegative after the second dose, 4 (24%) became seropositive following the third. Comparing the titers prior to the third dose, an increase of 50.7 (95 %CI 32.5-79.1) fold in the immunocompromised group and 25.7 (95 %CI 19.1-34.7) fold in and immunocompetent group, was observed.
Conclusion: A third BNT162b2 vaccine elicited robust humoral response, superior to the response observed following the second, among immunocompetent and immunocompromised individuals.
Keywords: BNT162b2 vaccine; Booster; COVID-19; Humoral response; Immunocompromised; Third vaccine dose.
【저자키워드】 COVID-19, BNT162b2 vaccine, Humoral response, Immunocompromised, booster, Third vaccine dose., 【초록키워드】 SARS-CoV-2, IgG, spike, antibody, prospective observational study, vaccine dose, BNT162b2, Seroconversion, age, women, seropositive, seronegative, IgG titer, administration, dose, humoral, Participants, immunocompromised individuals, second dose, participant, robust, evaluate, conducted, calculated, groups, elicited, subset, the antibody response, were measured, Spike IgG titer, 【제목키워드】 Antibody Response, healthy individuals, longitudinal cohort study,