A Competitive Serological Assay Shows Naturally Acquired Immunity to Human Papillomavirus Infections in the Guanacaste Natural History Study

Both assays showed an association between positive results and significant protection from subsequent infections for HPV16 and HPV18 combined. cLIA seroprevalence was lower than VLP ELISA, suggesting that the assay detects a subset of antibodies following natural infection that are specifically linked to immunity against subsequent HPV infection.