Acquired immune response to oncogenic human papillomavirus associated with prophylactic cervical cancer vaccines

Abstract

Human papillomavirus (HPV) is a common infection among women and a necessary cause of cervical cancer. Oncogenic HPV types infecting the anogenital tract have the potential to induce natural immunity, but at present we do not clearly understand the natural history of infection in humans and the mechanisms by which the virus can evade the host immune response. Natural acquired immune responses against HPV may be involved in the clearance of infection, but persistent infection with oncogenic virus types leads to the development of precancerous lesions and cancer. B cell responses are important for viral neutralization, but antibody responses in patients with cervical cancer are poor. Prophylactic vaccines targeting oncogenic virus types associated with cervical cancer have the potential to prevent up to 80% of cervical cancers by targeting HPV types 16 and 18. Clinical data show that prophylactic vaccines are effective in inducing antibody responses and in preventing persistent infection with HPV, as well as the subsequent development of high-grade cervical intraepithelial neoplasia. This article reviews the known data regarding natural immune responses to HPV and those developed by prophylactic vaccination.

Human Papillomavirus 16 (HPV 16) and HPV 18 Antibody Responses Measured by Pseudovirus Neutralization and Competitive Luminex Assays in a Two- versus Three-Dose HPV Vaccine Trial

“…Human papillomavirus (HPV) vaccines induce type-specific neutralizing antibodies (NAb) which correlate with immunity (5). The quadrivalent HPV (Q-HPV) vaccine (Gardasil; Merck Laboratories), which consists of HPV 6, HPV 11, HPV 16, and HPV 18 virus-like particles (VLPs), is currently licensed for a 3-dose regimen.…”

Human papillomavirus viral load in cervical intraepithelial neoplasia as a prognostic factor in a Mexican population

“…This result can be explained by the frequent misclassification of lesion grade in samples (Briolat et al, 2007). The CIN2 grade has the highest level of misclassification owing to variability in interpretation by the observer; CIN2 can represent the spectrum of late CIN1, CIN2, or early CIN3 (Briolat et al, 2007;Xi et al, 2008); true CIN2 is thought of as an early phenotype of high-grade CIN, a true cervical precancerous lesion (Einstein, 2008).…”

HPV vaccine: Cervarix

“…However, because a correlate of protection has not been established the minimal level of antibody required is not known and, therefore, a judgement cannot yet be made as to whether the higher levels will result in longer protection. However, in this context, it is interesting that the antibody response to HPV-18 appears to be maintained at high levels for longer with Cervarix than Gardasil [48]. Mathematical modeling suggests that, even using conservative assumptions, antibody levels for Cervarix will remain well above levels induced by natural infection for at least 20 years [36].…”