PSMD1 and schistosomiasis: Overall, the three primary objectives of the study were (i) to assess the COVID-19 vaccination status in rural schistosomiasis endemic areas; (ii) to estimate the approximate distribution of antibody levels against the S1 protein in COVID-19 vaccinees; and (iii) to investigate the effects of schistosome infection intensity on serological responses against the S1 subunit in COVID-19 vaccinees.