While starting in France the seasonal flu vaccination campaign, the French are reluctant to be vaccinate. One of the reasons mentioned would be the fear of contracting neurological disorders such as multiple sclerosis.
In truth, and according to a study that appeared online in the scientific journal JAMA Neurology on October 20, 2014, there is no proven association between vaccination and increased neurological disorders.
Researchers in California analyzed data from 780 patients with central nervous system disorders, and 3,885 healthy individuals, making up the control group.
The vaccinations received by the patients were identified through their electronic records, allowing the research team to assess the link between these vaccinations and the subsequent development of neurological disorders.
No causal effect was then found between the vaccines administered (including the Papillomavirus and Hepatitis B vaccines often incriminated) and the increased risk of multiple sclerosis or any other neurological disease, up to 3 years after the vaccination.
However, a link did appear in young patients, but it disappeared 30 days after administration of the vaccine. For the researchers, “the vaccine is at most an amplifier of the pre-existing autoimmunity”, in other words everything depends on the immunity of each person at the time of the vaccine. The latter could simply shed light on an underlying neurological disorder that is about to break out. But “nothing to call into question the current vaccination policies”.
The importance of a large sample
For the researchers, all studies examining the link between vaccinations and neurological diseases are controversial, because of the samples studied.
Regarding this study, the research team wishes to qualify its results on the vaccine against the Papillomavirus, because it has only been tested on 92 young women, aged 9 to 26 years.
Other limitations of the study include the low number of elderly people and the inability to assess subgroups at high risk of neurological disease, due to family history in particular.
Be that as it may, the benefit / risk balance of vaccines remains satisfactory for the time being, enough to reassure the most worried. Especially since some vaccines are mandatory.
