Since September 2008 the human papillomavirus (HPV) vaccine Cervarix has been used extensively in the UK routine HPV immunisation programme to prevent cervical cancer. We have previously reported on the safety of the vaccine following the first and second year of use.
While its safety evaluation has been continuous, we conducted a further safety review of the totality of the UK experience with Cervarix up to the end of July 2012. No new safety concerns were identified and the number and nature of adverse reaction (ADR) reports received was as expected after administration of at least 6 million doses of the vaccine in the UK.
Before Cervarix was first used the MHRA anticipated that a range of medical conditions naturally prevalent in the adolescent female population would occur in temporal association with vaccination and might be reported as suspect side effects. Statistical methods were therefore put in place to rapidly assess whether such reports were consistent with chance, or whether they could be new side effects of the vaccine.
One such condition was chronic fatigue syndrome (CFS) – the level of reporting for which was found to be well within the expected background incidence rate. An ecological study and a self-controlled case series study using the Clinical Practice Research Datalink (CPRD) also did not find an increased risk of fatigue syndromes with Cervarix.
Overall, the safety experience with Cervarix up to the end of July 2012 supports the previous conclusion that the balance of benefits and risks of Cervarix remains clearly positive.