Abstract
Background: Real-world population studies have shown waning immunity, over time, after receiving the two doses of the BNT162b2 COVID-19 vaccine. Studies reporting the long-term humoral response are important to drive future vaccination strategies like the introduction of the booster dose. Yet, available literature on long follow-up periods is scarce. Covidiagnostix is a multicenter study aiming to assess the antibody response in >1000 healthcare professionals (HCPs) who received the BNT162b2 vaccine.
Methods: Serum was tested at time-0 (T0), before the first dose and then at T1, T2, T3 and T4, respectively, 21, 42, 177 and 302 days after T0. Antibodies against the SARS-CoV-2 nucleocapsid-protein were measured to assess SARS-CoV-2 infections, whereas antibodies against the receptor-binding domain of the spike protein were measured to assess vaccine response.
Results: The antibody titer observed 10 months post-vaccination showed a decrease of approximately 80% from the peak measured at T2, yet the median titer of the seronegatives HCPs was still higher than seropositives before vaccination. We identified 12 post-vaccination infected HCPs within 6 months after receiving the first dose and another 12 post-vaccination infected HCPs between 6 and 10 months post-vaccination.
Conclusion: Vaccination induced a humoral response which is well detectable even 10 months post-vaccination. Yet a high anti-spike serum antibody titer does not guarantee protection from infection. Differences in symptomatology between SARS-CoV-2 infections occurred within the first 6 months post-vaccination and the following 4 months, and differences in COVID-19 prevalence and vaccination coverage observed in these two time intervals were consistent with a decrease in vaccine efficacy 6 months after receiving the first dose.
Keywords: COVID-19; Immune response; Post-vaccination infection; Roche anti-SARS-CoV-2-S; Serological test; Vaccination; mRNA vaccine.
【저자키워드】 COVID-19, serological test, immune response, vaccination, mRNA vaccine., Post-vaccination infection, Roche anti-SARS-CoV-2-S, 【초록키워드】 serological test, Efficacy, Vaccine, BNT162b2 vaccine, COVID-19 vaccine, immune response, antibody, mRNA vaccine, multicenter study, SARS-COV-2 infection, Antibody Response, vaccine efficacy, Infection, Spike protein, BNT162b2, Prevalence, serum, Coverage, Receptor-binding domain, Symptomatology, Humoral response, vaccine response, Antibody titer, serum antibody, multicenter, Roche, booster dose, SARS-CoV-2 infections, seropositive, seronegative, Anti-spike, Healthcare professional, dose, Vaccination strategy, waning immunity, humoral, time interval, time intervals, population studies, within 6 months, follow-up period, first dose, decrease, difference, hcp, median titer, seronegatives, shown, occurred, detectable, receiving, the spike protein, the receptor-binding domain, the antibody response, were measured, the median, the SARS-CoV-2, was tested, 【제목키워드】 SARS-COV-2 infection, large cohort, Healthcare professional, administration,