Immune Response to Human Papillomavirus One Year after Prophylactic Vaccination with AS04-Adjuvanted HPV-16/18 Vaccine: HPV-Specific IgG and IgA Antibodies in the Circulation and the Cervix

Document Type: Research Articles

Authors

1 Postgraduate Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, Brazil.

2 Department of Gynecology, and Obstetrics, Federal University of Rio Grande do Norte, Natal, Brazil.

3 Department of Clinical Analysis and Toxicology, Federal University of Rio Grande do Norte, Natal, Brazil.

4 Department of Gynecology and Obstetrics, University Potiguar, UnP Natal, Brazil.

5 Department of Gynecology, and Obstetrics, State University of Campinas, Campinas, Brazil.

6 Department of Obstetrics and Gynecology Weill Cornell Medical College, New York, NY, USA.

Abstract

Objective: This study was designed to describe the course of IgG/IgA responses in cervical secretions and in serum
one year after the first dose of intramuscular administration of the HPV16/18 AS04-adjuvant vaccine. Methods: Blood
and cervical mucus samples were collected for immunologic assays, 7 months after the first doses and 1 year following
the last boost vaccination (month 7) by enzyme linked immunosorbent assay (ELISA). The detection of IgG and IgA
anti-HPV/VLP was developed for this purpose. Result: A total of 100% of serum samples were IgG antibody positive
at a titer of 1:100 at both time periods and decreased according to the serum dilution. For serum IgA antibody, 95%
were positive one month after vaccination and 79% were positive 1 year later. Similar results were observed with
the cervical samples positive for both IgG and IgA antibodies at one month and decreasing after 1 year to 33% and
29%. The median absorbance in serum and the cervix for IgG and IgA anti-HPV-VLP antibodies was significantly
higher at one month after vaccination when compared to 1 year post-vaccination (P<0.0001). Conclusion: Immune
responses were significant one year after immunization, however it decreased in cervical and serum samples when
compared to levels observed one month after the last dose. This suggests that a vaccine booster may be necessary to
increase antibody titers.

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