Vaccines Raise MS Risk Sooner But Not Later

Author(s):

New study findings do not suggest a need for a change in vaccine policy, but even a small increased risk could have an effect on public health.

There is no longer-term association of vaccines with multiple sclerosis (MS) or any other acquired CNS demyelinating syndrome (CNS ADS), according to a new study.¹ The findings argue against a causal association.

However, there is a short-term increase in risk, suggesting that vaccines may accelerate the transition from subclinical to overt autoimmunity in patients who have existing disease.

Annette Langer-Gould, MD, PhD, from the Department of Research and Evaluation at Kaiser Permanente, Southern California, Pasadena, and colleagues conducted a nested case-control study to determine whether vaccines, particularly those for hepatitis B (HepB) and human papillomavirus (HPV) infection, increase the risk of MS or other CNS ADS. They used data from the complete electronic health records of Kaiser Permanente Southern California members on cases between 2008 and 2011. The evaluation included extensive review of medical records by an MS specialist. Five controls per case were matched on age, sex, and Zip code.

All forms of CNS ADS were analyzed using conditional logistic regression adjusted for race/ethnicity, health care utilization, comorbid diseases, and infectious illnesses before symptom onset.

The investigators identified 780 incident cases of CNS ADS and 3885 controls; 92 cases and 459 controls were females aged 9 to 26 years, the indicated age range for HPV vaccination.

There were no associations between HepB vaccination, HPV vaccination, or any vaccination and the risk of CNS ADS up to 3 years later. Vaccination of any type was associated with an increased risk of CNS ADS onset within the first 30 days after vaccination only in patients younger than 50 years.

The findings support clinical anecdotes of CNS ADS symptom onset shortly after vaccination but do not suggest a need for a change in vaccine policy, the researchers suggested. Because vaccinations are common, they noted, even a small increased risk of MS or other CNS ADS could have a significant effect on public health.