Antibody response after first and second BNT162b2 vaccination to predict the need for subsequent injections in nursing home residents

RBD-specific antibody response after two doses of different SARS-CoV-2 vaccines during the mass vaccination campaign in Mongolia

The SARS-CoV-2 vaccination campaign began in February 2021 and achieved a high rate of 62.7% of the total population fully vaccinated by August 16, 2021, in Mongolia. We aimed to assess the initial protective antibody production after two doses of a variety of types of SARS-CoV-2 vaccines in the Mongolian pre-vaccine antibody-naïve adult population. This prospective study was conducted from March-April to July-August of 2021. All participants received one of the four government-proposed COVID-19 vaccines including Pfizer/BioNTech (BNT162b2), AstraZeneca (ChAdOx1-S), Sinopharm (BBIBP-CorV), and Sputnik V (Gam-COVID-Vac). Before receiving the first shot, anti-SARS-CoV-2 S-RBD human IgG titers were measured in all participants (n = 1833), and titers were measured 21-28 days after the second shot in a subset of participants (n = 831). We found an overall average protective antibody response of 84.8% (705 of 831 vaccinated) in 21-28 days after two doses of the four types of COVID-19 vaccines. Seropositivity and titer of protective antibodies produced after two shots of vaccine were associated with the vaccine types, age, and residence of vaccinees. Seropositivity rate varied significantly between vaccine types, 80.0% (28 of 35) for AstraZeneca ChAdOx1-S; 97.0% (193 of 199) for Pfizer BNT162b2; 80.7% (474 of 587) for Sinopharm BBIBP-CorV, and 100.0% (10 of 10) for Sputnik V Gam-COVID-Vac, respectively. Immunocompromised vaccinees with increased risk for developing severe COVID-19 disease had received the Pfizer vaccine and demonstrated a high rate of seropositivity. A high geometric mean titer (GMT) was found in vaccinees who received BNT162b2, while vaccinees who received ChAdOx1-S, Sputnik V, and BBIBP-CorV showed a lower GMT. In summary, we observed first stages of the immunization campaign against COVID-19 in Mongolia have been completed successfully, with a high immunogenicity level achieved among the population with an increased risk for developing severe illness.

The association between antipyretic analgesics use and SARS-CoV-2 antibody titers following the second dose of the BNT162b2 mRNA vaccine: An observational study

Antipyretic analgesics are used to manage and control symptoms occurring after vaccination, but may hamper immunogenicity or vaccine efficacy. We examined the association between prophylactic or therapeutic use of antipyretic analgesics and SARS-CoV-2 antibody titers for vaccine recipients. Data were obtained from 1,498 staff members of a medical and research institution in Tokyo, Japan, who had received the second dose of the BNT162b2 vaccine. We quantitatively measured anti-SARS-CoV-2 spike protein IgG titers in the participants three months after vaccination. The prophylactic and therapeutic use of antipyretic analgesics was ascertained via a questionnaire. A linear regression model was used to examine the association between antipyretic analgesic use and log-transformed anti-SARS-CoV-2 spike protein IgG titers. Based on model parameters, we estimated geometric mean titers (GMT) and the corresponding 95 % confidence intervals (CI). The results showed that IgG titers in vaccine recipients who used antipyretic analgesics therapeutically was higher than the titers in those who did not (geometric mean ratio [GMR] = 1.26, 95 % CI = 1.17-1.34) with GMTs being 6,147 (95 % CI = 5,833-6,460) and 4,895 (95 % CI = 4,676-5,115) for those who used antipyretic analgesics therapeutically and those who did not, respectively. The association was attenuated, but remained statistically significant after adjusting for symptoms (GMR = 1.14, 95 % CI = 1.06-1.23). We did not find any evidence of significant association in relation to the prophylactic use of antipyretic analgesics (GMR = 0.96, 95 % CI = 0.84-1.10), with GMTs being 5,245 (95 % CI = 4,577-5,913) and 5,452 (95 % CI = 5,258-5,645) for those who used antipyretic analgesics prophylactically and those who did not, respectively. In conclusion, we did not find any evidence of suppression of the humoral response after the second dose of SARS-CoV-2 vaccination by prophylactic or therapeutic use of antipyretic analgesics.