Dataset Information

Decline of antibody titres 3 months after two doses of BNT162b2 in non-immunocompromised adults.

ABSTRACT:

Objective

To assess the antibody response in non-immunocompromised adults after two doses of BNT162b2.

Methods

Prospective, single-centre observational study in non-immunocompromised adults aged 18 years or more who received two doses of BNT162b2. The study contemplates analyses of serum samples collected 1.5, 3, 6, 9 and 12 months after the second dose of BNT162b2; results of the 1.5- and 3-month time-points are presented in this report. Antibodies against the receptor binding domain of the S1 subunit of the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (anti-RBD antibodies) were measured using a commercial quantitative immunoassay. A threshold of 4160 AU/mL (corresponding to an ID₅₀ of 1:250) was used as surrogate marker for serum neutralizing activity.

Results

Of 273 hospital workers who received two doses of BNT162b2, 260 (95%) agreed to participate in the study; 2/260 (0.8%) were excluded because of immunocompromised conditions. At the time of this report, 230/258 (89%) participants (mean age 46.0 years (SD 11.4 years); 143/230 (62%) female; 87/230 (38%) male) had completed 3 months of follow up after the second dose of BNT162b2. Thirty-six (16%) of the 230 had documented mild SARS-CoV-2 infection before receiving the first dose of BNT162b2. Median (interquartile range (IQR)) anti-RBD titres 1.5 months after vaccination were 9356 (5844-16 876) AU/mL; 3 months after vaccination, median anti-RBD titres had declined to 3952 (2190-8561) AU/mL (p < 0.001). Of 199/230 (86.5%) participants who had anti-RBD titres above 4160 AU/mL 1.5 months after the second dose of BNT162b2, only 95/230 (41%) maintained anti-RBD titres above this level 3 months after vaccination (p < 0.001).

Conclusions

The decline of anti-RBD antibodies 3 months after the second dose of BNT162b2 is of concern because it raises the possibility of a short-lived humoral immunity after vaccination. Booster doses of BNT162b2 might be required to maintain high titres of anti-RBD antibodies over time.

SUBMITTER: Erice A

PROVIDER: S-EPMC8426320 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:ObjectivesVaccination against SARS-CoV-2 has been extensively deployed during COVID-19 pandemic. One efficient method to evaluate response to vaccination is the assessment of humoral immunity by measuring SARS-CoV-2 antibody titres. We investigated the association between anthropometric parameters (age, body mass index), smoking, diabetes, statin use, hypertension, levels of 25(OH)D and dehydroepiandrosterone sulfate (DHEAS), and SARS-CoV-2 antibody titres after vaccination.DesignIn this longitudinal observational cohort study, 712 subjects were tested for SARS-CoV-2 antibodies 3 months after the second dose of BNT162b2 vaccine. Multiple linear regression analysis was performed to identify which factors are associated with the antibody titres.SettingHealthcare units of western Greece (University Hospital of Patras and "St Andrews" State General Hospital of Patras).ParticipantsAll adults receiving their second dose of BNT162b2 vaccine at the participating healthcare units were eligible to participate in the study. Exclusion criteria were SARS-CoV-2 infection or positive SARS-CoV-2 antibody titre at baseline. Patients who did not provide all necessary information were excluded from our analyses.ResultsWe found age to be negatively associated with antibody titre (-0.005; 95% CI -0.009 to -0.001, p=0.0073), as was male gender (-0.11; 95% CI -0.1738 to -0.04617, p=0.0008). The interaction of age and gender was significant (-0.01090; 95% CI -0.01631 to -0.005490, p<0.0001), highlighting that the rate of decline in antibody titre with increasing age tends to be higher in men rather than in women. No linear trend was found between DHEAS levels and antibody titres when the lower quartile of DHEAS levels was used as reference. Tobacco use was associated with low antibody titre (-0.1097; 95% CI -0.174 to -0.046, p=0.0008) but overweight, obese or underweight subjects had similar antibody responses to normal-weight individuals. Although subjects with diabetes and hypertension had numerically lower antibody titres, this association was not statistically significant. Vitamin D levels showed no clear relationships with antibody titres.ConclusionsAge, male gender and tobacco use are negatively associated with antibody titres after COVID-19 vaccination, but our data showed no clear correlation with vitamin D levels.Trial registration numberNCT04954651; Results.