Relationship between Papillomavirus vaccine, vaginal microbiome, and local cytokine response: an exploratory research

The influence of vaccination on composition of the human microbiome at distinct sites has been recognized as an essential component in the development of new vaccine strategies. The HPV vaccine is widely used to prevent cervical cancer; however, the influence of HPV vaccine on the vaginal microbiota has not been previously investigated. In his study, we performed an initial characterization of the microbiome and cytokine composition in the vagina following administration of the bivalent vaccine against HPV 16/18.

In this exploratory study, fifteen women between 18 and 40 years received three doses of the HPV-16/18 AS04-adjuvanted vaccine (Cervarix®). Cervicovaginal samples were collected before the first dose and 30 days after the third dose. HPV genotyping was performed by the XGEN Flow Chip technique. The cytokines IFN-γ, IL-2, IL-12p70, TNF-α, GM-CSF, IL-4, IL-5, IL-10, and IL-13 were quantitated by multiplex immunoassay. The vaginal microbiome was identified by analysis of the V3/V4 region of the bacterial 16S rRNA gene.

The most abundant bacterial species in the vaginal microbiome was Lactobacillus crispatus, followed by L. iners. Bacterial diversity and dominant organisms were unchanged following vaccination. Small decreases in levels of pro and anti-inflammatory cytokines were observed following HPV vaccination, but there was no association between vaginal cytokine levels and microbiome composition.

Vaginal microbiome is not altered following administration of the standard three-dose HPV-16/18 AS04-adjuvanted (Cervarix®) vaccine.