Protective Human Papillomavirus Type 16/18 Vaccine-Induced Neutralizing Antibody Levels Remain Elusive.

Area of Science:

• Immunology
• Oncology
• Virology

Background:

• Adolescent vaccination against human papillomavirus (HPV) 16/18 is crucial for cervical cancer prevention.
• High-grade squamous cell intraepithelial lesions (HSILs) are precursors to cervical cancer.
• Understanding the immune response to HPV vaccination is vital for assessing vaccine efficacy.

Purpose of the Study:

• To investigate neutralizing antibody levels in women who received HPV 16/18 vaccination and subsequently developed cervical HSILs.
• To compare antibody levels between HSIL cases and vaccinated controls with or without persistent HPV infection.
• To assess the long-term presence of protective vaccine-induced antibodies.

Main Methods:

• Analysis of a subset of a cohort of 16,988 women vaccinated against HPV 16/18 in adolescence.
• Comparison of neutralizing antibody levels (HPV16/18 and HPV33) between 50 HSIL cases and matched controls.
• Longitudinal follow-up over 16 years.

Main Results:

• No significant difference in HPV16/18 neutralizing antibody levels was observed between HSIL cases and vaccinated controls.
• HSIL cases showed significantly increased cross-neutralizing antibody levels against HPV33 compared to HPV16/18.
• Protective vaccine-induced, HPV16/18 cross-neutralizing antibody levels were not consistently detected during 16 years of follow-up.

Conclusions:

• HPV 16/18 vaccination did not correlate with altered neutralizing antibody levels in adolescents who later developed cervical HSILs.
• Increased HPV33 antibodies in HSIL cases suggest potential cross-reactivity or alternative infection pathways.
• The long-term persistence of protective vaccine-induced neutralizing antibodies against HPV 16/18 requires further investigation.