Researchers were not able to find a link between certain vaccines, especially those for hepatitis B (HepB) and human papillomavirus (HPV), and multiple sclerosis (MS) risk.
The researchers concluded any perceived correlation between vaccines and risk of MS was due to existing disease, The JAMA Network Journals reported. In the past studies have had mixed results as to whether or not these vaccines are linked to MS risk.
To make their findings the researchers looked at the relationship between vaccines and MS and other system demyelinating syndromes (CNS ADS) using data from Kaiser Permanente Southern California members. The team looked at 780 cases of CNS ADS 3,885 control group patients; out of the data pool 92 of the patients with the conditions and 459 controls were females between the ages of 9 and 26, which is the typical age range for the HPV vaccine.
There did not appear to be a link between "HepB vaccinations, HPV vaccination or any vaccination and the risk of MS or CNS ADS up to three years later," the researchers reported. Vaccinations of any type were associated with an increased risk of a CNS ADS within 30 days of when it was administered, but this relationship disappeared after 30 days and did not exist at all in patients under the age of 50.
These findings suggest vaccines do not cause these types of conditions, but could speed up the transition from subclinical to overt autoimmunity in patients who already have the disease but do not yet show symptoms.
The study's results for HPV are considered inconclusive because there have been few studies on the topic in the past, and the sample size was relatively small.
"Our data do not support a causal link between current vaccines and the risk of MS or other CNS ADS. Our findings do not warrant any change in vaccine policy," the researchers stated.
The findings were published Oct. 20 in the journal JAMA Neurology.
