Abstract
Background
Histo–blood group antigen (HBGA) Lewis/secretor phenotypes predict genotype-specific susceptibility to rotavirus gastroenteritis (RVGE). We tested the hypothesis that nonsecretor/Lewis-negative phenotype leads to reduced vaccine take and lower clinical protection following vaccination with G1P[8] rotavirus vaccine (RV1) in Malawian infants
Methods
A cohort study recruited infants receiving RV1 at age 6 and 10 weeks. HBGA phenotype was determined by salivary enzyme-linked immunosorbent assay (ELISA). RV1 vaccine virus shedding was detected by quantitative real-time polymerase chain reaction (qRT-PCR) in stool collected on alternate days for 10 days post-immunization. Plasma rotavirus–specific immunoglobulin A was determined by ELISA pre- and post-immunization. In a case-control study, HBGA phenotype distribution was compared between RV1-vaccinated infants with RVGE and 1:1 age-matched community controls. Rotavirus genotype was determined by RT-PCR.
Results
In 202 cohort participants, neither overall vaccine virus fecal shedding nor seroconversion differed by HBGA phenotype. In 238 case-control infants, nonsecretor phenotype was less common in infants with clinical vaccine failure (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.20–0.75). Nonsecretor phenotype was less common in infants with P[8] RVGE (OR, 0.12; 95% CI, 0.03–0.50) and P[4] RVGE (OR, 0.17; 95% CI, 0.04–0.75). Lewis-negative phenotype was more common in infants with P[6] RVGE (OR, 3.2; 95% CI, 1.4–7.2).
Conclusions
Nonsecretor phenotype was associated with reduced risk of rotavirus vaccine failure. There was no significant association between HBGA phenotype and vaccine take. These data refute the hypothesis that high prevalence of nonsecretor/Lewis-negative phenotypes contributes to lower rotavirus vaccine effectiveness in Malawi.
Histo–Blood Group Antigen Phenotype Determines Susceptibility to Genotype-Specific Rotavirus Infections and Impacts Measures of Rotavirus Vaccine Efficacy