Impact of ABO Blood System on Immunogenicity and Vaccine Efficacy of COVID-19 Booster Vaccination-A Population-Based Study of 3066 Individuals.

BACKGROUND

ABO blood group has been associated with SARS-CoV-2 susceptibility. Little data exist regarding the impact of ABO and Rhesus (Rh[D]) type on breakthrough infections and antibody responses following SARS-CoV-2 booster vaccination.

METHODS

This multicenter, population-based cohort study includes individuals ≥ 18 years who received a booster vaccination against SARS-CoV-2. Antibody levels against SARS-CoV-2 receptor binding domain (RBD) and neutralizing antibodies against wild-type (WT) virus and Omicron variant were assessed at baseline, after 4 weeks and after 6 months. At 6 months follow-up, self-reported ABO and Rh(D) type, time to, and severity of breakthrough infections were collected.

RESULTS

In total, 3066 participants (mean age 49 [35-59], 62% female) were included in multivariable regression models, showing no association of anti-RBD and neutralizing antibodies against wild-type and Omicron variant with ABO or Rh(D) 4 weeks after booster vaccination. Time-dependent Cox regression analysis showed significantly lower rates of breakthrough infections in patients with AB (hazard ratio [HR] 0.67 [0.50-0.90]; p = 0.008) compared to O, even after adjustment for relevant covariates and a trend for blood group B (HR 0.82 [0.66-1.01]; p = 0.06) compared to O; there were no associations between Rh(D) and breakthrough infection rates or between observed (asymptomatic to moderate) COVID-19 symptom severity and ABO or Rh(D) blood group.

CONCLUSIONS

ABO or Rh(D) blood group was not associated with COVID-19 severity or antibody responses following SARS-CoV-2 vaccination. Breakthrough infections were least common in blood groups AB and B. Although our data do not support previously discussed protective effects of anti-A/B/Rh(D) agglutinins, differences in ABO group appear relevant for Omicron transmission.