Cross-Protective IgG and IgA Antibodies against Oncogenic and Non-Oncogenic HPV Genotypes

OBJECTIVE: The aim of the study was to describe the course of IgG/IgA immune response in women immunized with bivalent vaccine and in women non-vaccinated with HPV infection, as well as evaluating the cross-protection against non-vaccine HPV types. METHODS: Serum and cervical mucus samples were collected from infected and vaccinated women for HPV detection/genotyping and for detection of IgG/IgA anti-HPV/VLP (Virus-like Particles) by ELISA. RESULTS: The median absorbance detected in serum samples for anti-HPV-IgG antibodies was higher in vaccinated women when compared to HPV infected women (p <0.01), however, the median absorbance in cervical mucus samples for anti-HPV-IgA was higher in infected women when compared to vaccinated women (p<0.01). Additionally, our analyses also provided additional evidence for cross-protective efficacy of the HPV-16/18 vaccine against HPV-82, -6, -11, -13, -61, -72 and -74. CONCLUSION: The IgG antibodies were significantly more detected in the serum of vaccinated women, while the IgA was found in greater quantities in cervical samples from those infected by the virus. In addition, there is evidence that the bivalent vaccine provides cross-protection against other non-oncogenic viral subtypes.