Multiple sclerosis and vaccination against hepatitis B: analysis of risk benefit profile

Background. Since 1994, the hypothesis of a potential Introduction causal r elationship between vaccination against hepatitis B and multiple sclerosis (and other demyelinating diseases) was brought to the attention of the Fren ch health authority and to public debate. In Italy, since 1991, vaccination against hepatitis B has been mandatory for newborns and 12-year-old childr en, and also recommended for high-risk groups. Aim. To re-evaluate the risk/benefit profile of the Italian strategy of hep atitis B vaccination. Subjects, The study population is a hypothetical coho rt of 100,000 newborns, Methods, We present a simulation of the hepatitis B cases that could be pre vented with the vaccination and of the potential excess of multiple scleros is cases which would occur; assuming different adds ratios of multiple scle rosis among vaccinees, and by effecting the vaccination at different ages. Results. In the cohort, we would expect 1099 hepatitis B cases. that could be prevented,vith vaccination. Assuming that the highest odds ratio of 1.7 reported is true, the excess of "life-time" multiple sclerosis incidence wo uld be 0.3% for 12-year-old subjects, and 2.9% for adults. Conclusions, On the basis of these data, our opinion is that the hepatitis B vaccination strategy presently adopted in Italy for newborns, teen-agers and high risk groups should not be modified.