By Dr. Mercola
In 1988, the first conjugate vaccine was approved for use in the U.S.
It was intended to protect infants and young children against Haemophilus influenzae type b (Hib); a bacterial infection that can lead to pneumonia, infections of your blood, joints, bones, and pericardium.
Historically, it has also been a leading cause of bacterial meningitis.
Since that time, the vaccine has been approved in most developed countries, including Denmark and Israel where the vaccine was added to their national vaccine programs in 1993 and 1994, respectively.
Starting in the late 1980's, there was a marked increase in the reported prevalence of autism spectrum disorders among children in the U.S.
A similar increase was seen in Denmark and Israel.
While the rise may be a reflection of "ascertainment biases," researchers now suggest the Hib vaccine may be another trigger.
The continuation of the trend toward increased rates of autism spectrum disorders could be further explained by the increased usage of the vaccine.