The NHS currently covers the MSD vaccine called Gardasil, which protects against HPV types 6, 11, 16 and 18. It is generally given as using a 2-dose schedule with the 1st injection at any chosen date and the 2nd injection 6 months after the first injection. In comparison the newer and better Gardasil-9 vaccine, covers HPV types 6, 11, 16, 18, 31, 33, 45, 52 and 58. Gardasil 9 can be administered according to a 2 dose schedule, with the second dose being administered between 5 and 13 months after the first dose. If the second vaccine dose is administered earlier than 5 months after the first dose, a third dose should always be administered. Another option is to use the 3-dose (0, 2, 6 months) schedule.
Mouchet et al. Human papillomavirus vaccine and demyelinating diseases-A systematic review and meta-analysis. Pharmacol Res. 2018 Apr 14. pii: S1043-6618(18)30288-3.
BACKGROUND: Approved in 2006, human papillomavirus (HPV) vaccines were initially targeted for girls aged 9-14 years. Although the safety of these vaccines has been monitored through post-licensure surveillance programmes, cases of neurological events have been reported worldwide.
PURPOSE: The present study aimed to assess the risk of developing demyelination after HPV immunization by meta-analysing risk estimates from pharmacoepidemiologic studies.
DATA SOURCES: A systematic review was conducted in Medline, Embase, ISI Web of Science and the Cochrane Library from inception to 10 May 2017, without language restriction.
STUDY SELECTION: Only observational studies including a control group were retained. Study selection was performed by two independent reviewers with disagreements solved through discussion.
DATA EXTRACTION: This meta-analysis was performed using a generic inverse variance random-effect model. Outcomes of interest included a broad category of central demyelination, multiple sclerosis (MS), optic neuritis (ON), and Guillain-Barré syndrome (GBS), each being considered independently. Heterogeneity was investigated; sensitivity and subgroup analyses were performed when necessary. In parallel, post-licensure safety studies were considered for a qualitative review. This study followed the PRISMA statement and the MOOSE reporting guideline.
DATA SYNTHESIS: Of the 2863 references identified, 11 articles were selected for meta-analysis. No significant association emerged between HPV vaccination and central demyelination, the pooled odds ratio being 0.96 [95%CI 0.77-1.20], with a moderate but non-significant heterogeneity (I2 = 29%). Similar results were found for MS and ON. Sensitivity analyses did not alter our conclusions. Findings from qualitative review of 14 safety studies concluded in an absence of a relevant signal.
LIMITATIONS: Owing to limited data on GBS, no meta-analysis was performed for this outcome.
CONCLUSION: This study strongly supports the absence of association between HPV vaccines and central demyelination.