ClinicSpeak: human papillomavirus vaccination has no effect on MS risk

Good news; HPV vaccination does not increase MS risk. #ClinicSpeak #MSBlog #MSResearch

“Epidemiology doesn’t get better than this. In a large case control study in Denmark and Sweden there is no evidence that the quadrivalent HPV (human papilloma virus) vaccine triggers MS or other demyelinating diseases. People who develop MS shortly after a vaccination tend to blame the vaccine, but as so many people get vaccinated it could simply be a chance association due to recall bias. This HPV study is important to me; I look after a young girl who developed devastating ADEM (acute disseminated encephalomyelitis) 3 weeks after her first dose of the HPV vaccine. We all assumed that the vaccine triggered her ADEM; this study suggests not. Her parents may be interested in knowing about this study, I am not sure they will be as accepting as me about the results.”

“Since the MMR (measles, mumps and rubella) scare in relation to autism the general population have been very wary of vaccines, even if the health benefits of the vaccine are well established. HPV vaccine prevents women getting cervical and anal cancer and may prevent a proportion of oral and esophageal cancers. The Department of Health are considering extending the vaccination programme to boys and to older women. An interesting trend in the UK and other countries is a surge in sexually transmitted diseases in older women who are becoming sexually active after losing, or splitting-up, with the partners. Sociologists tell us this is being driven by internet dating sites; as these sites become more ubiquitous and socially acceptable they are changing our social and sexual behaviour.”

“I am a big fan of Harald zur Hausen the virologist who first discovered the link between HPV and cervical cancer. The community refused to accept the evidence. He never gave in and eventually the evidence became so overwhelming that Pharma developed several vaccines that were shown to be safe. Large studies have now shown the HPV vaccination prevents cervical cancer; i.e. proving Zur Hausen’s hypothesis. The other paradigm change was that his worked showed that cervical and anal cancer are sexually transmitted diseases.  The community finally recapitulated and Harald zur Hausen was awarded the Nobel Prize for medicine in 2008.”

“The Zur Hausen story is is a fine example of Arthur Schopenhauer’s Dictum.” 

All truth passes through three stages:
  1.  It is ridiculed
  2.  It is violently opposed
  3.  It is accepted as self-evident

IMPORTANCE: Case reports have suggested a link between human papillomavirus (HPV) vaccination and development of multiple sclerosis and other demyelinating diseases.

OBJECTIVE: To investigate if quadrivalent HPV (qHPV) vaccination is associated with an increased risk of multiple sclerosis and other demyelinating diseases.

DESIGN, SETTING, AND PARTICIPANTS: Using nationwide registers we identified a cohort of all females aged 10 years to 44 years in Denmark and Sweden, followed up from 2006 to 2013, information on qHPV vaccination, and data on incident diagnoses of multiple sclerosis and other demyelinating diseases. The primary analysis used a cohort design including vaccinated and unvaccinated study participants. A secondary analysis used a self-controlled case-series design including only cases. Both analyses used a 2-year risk period following vaccination.

EXPOSURES: Information on qHPV vaccination was obtained through the national vaccination and prescription registers.

MAIN OUTCOMES AND MEASURES: The primary outcomes were multiple sclerosis and a composite end point of other demyelinating diseases. Incidence rate ratios were estimated using Poisson regression, comparing rates of events in the 2-year risk periods following vaccination and in unvaccinated time periods.

RESULTS: The study included 3,983,824 females, among whom 789,082 received a total of 1,927,581 qHPV vaccine doses. During follow-up, 4322 multiple sclerosis cases and 3300 cases of other demyelinating diseases were identified, of which 73 and 90, respectively, occurred within the risk period. In the cohort analysis, there was no increased risk of multiple sclerosis (crude incidence rates, 6.12 events/100,000 person-years [95% CI, 4.86-7.69] and 21.54 events/100,000 person-years [95% CI, 20.90-22.20] for the vaccinated and unvaccinated periods; adjusted rate ratio, 0.90 [95% CI, 0.70-1.15]) or other demyelinating diseases (crude incidence rates, 7.54 events/100,000 person-years [95% CI, 6.13-9.27] and 16.14 events/100,000 person-years [95% CI, 15.58-16.71]; adjusted rate ratio, 1.00 [95% CI, 0.80-1.26]) associated with qHPV vaccination. Similarly, no increased risk was found using the self-controlled case-series design (multiple sclerosis: incidence ratio, 1.05 [95% CI, 0.79-1.38]; other demyelinating diseases: incidence ratio, 1.14 [95% CI, 0.88-1.47]).

CONCLUSIONS AND RELEVANCE: In this study with nationwide coverage of 2 Scandinavian countries, qHPV vaccination was not associated with the development of multiple sclerosis or other demyelinating diseases. These findings do not support concerns about a causal relationship between qHPV vaccination and demyelinating diseases.

About the author

Prof G

Professor of Neurology, Barts & The London. MS & Preventive Neurology thinker, blogger, runner, vegetable gardener, husband, father, cook and wine & food lover.


  • What about if you actually caught the virus from your partner? Have any studies been done on the effects of infection on MS?

  • This vaccination study, as well as others, does not mean that absolutely, positively, that there are zero individuals who may have an adverse reaction which causes to MS. What they do say is that these adverse reactions that cause MS are not evident at a particular confidence level. Although relatively small, there is a difference between 95% confidence, 99%, 99.999% and so on; especially when this is multiplied by millions. Hence, its good that the risk for MS due to HPV vaccination is very low; however the study does not mean its 100% safe. What would be needed is for each person to have a relevant medical evaluation (across many tests) prior to a vaccination, and then have a post-vaccination evaluation. Such a procedure would be too costly at the moment on millions of people. Though perhaps one day in 100 years when medicine is truly personalized and diagnostics are close to being free, then maybe this could be known.

  • This study is about developing MS. What do we know of effects on people who already have MS: can the vaccination cause fresh activity?

    Another question: will the vaccination be effective if a MSer is on anti-CD20 treatment?

By Prof G



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