Hepatitis B vaccine
The Hepatitis B vaccine is a vaccine which is effective in preventing Hepatitis B in both pre and post exposure cases 80 - 95% of the time. Most states require that children be administered this vaccine before they are admitted to public school. One study has proposed that the vaccine may increase the risk of multiple sclerosis, though additional studies have not found any correlation, and neither the World Health Organization nor Centers for Disease Control regard the vaccine as unsafe, both of which recommend that all school children receive it.
France has opened a criminal investigation for manslaughter against managers in companies that promoted the Hepatitis B vaccine in that country, for allegedly concealing the adverse effects.
Recombinant hepatitis B vaccine and the risk of multiple sclerosis
A 2004 study examined cases of 163 cases of MS and 1,604 controls. The OR of MS for vaccination within 3 years before the index date compared to no vaccination was 3.1 (95% CI 1.5, 6.3). No increased risk of MS was associated with tetanus and influenza vaccinations. The study concluded that the findings were consistent with the hypothesis that immunization with the recombinant hepatitis B vaccine is associated with an increased risk of MS, and challenged the idea that the relation between hepatitis B vaccination and risk of MS is well understood. However, seven separate studies of much larger sample sizes conducted between 1999 and 2001 found that any correlation between the hepatitis B vaccination and multiple sclerosis was statistically insignificant.