This is a reasonable concern because the issue has received a lot of attention in the press in recent years. But most experts believe that a child's immune system is well equipped to handle the antigens, or immune triggers, contained in multiple vaccines.
Children's immune systems are stronger than you think: They're designed to protect kids from the hundreds, even thousands, of foreign bodies they're exposed to each day in the form of fungi, parasites, bacteria, and viruses. In fact, children are exposed to more antigens in the environment every day than to those in all their vaccinations combined. And because of innovations in the way vaccines are made, today's vaccines contain far fewer antigens than those administered in the past.
Health experts have been sufficiently concerned about this issue, however, to provoke extensive research and analysis. The theory is that overloading the immune system with vaccines could weaken a child's defense against infection or trigger an autoimmune disease such as type 1 diabetes. There has also been concern that the large number of vaccines in today's recommended schedule exposes children to too many antigens at once, possibly triggering allergies or asthma.
To address these fears, the U.S. Centers for Disease Control (CDC) and National Institutes of Health (NIH) commissioned the Institute of Medicine (IOM) to study the question of whether multiple vaccines could harm a child's immune system.
The IOM report, published in 2002, concluded that there's no evidence of a connection between multiple vaccines and increased infection or autoimmune disease. If there were, experts say, the rate of infection and diabetes in vaccinated children would be higher than in unvaccinated ones, and that doesn't appear to be the case. You can view the results of these studies on the IOM website.
More recent studies at the University of Louisville also found that young children who receive multiple vaccines in the first year of life are no more likely than children who had fewer vaccines to have any developmental problems. In fact, the infants who were fully vaccinated performed better in some areas of brain development than the group with delayed immunizations. This is very reassuring news for those parents who worry about vaccines.
As for a connection between vaccines and allergies and asthma, the situation is less clear. Experts say that studies to date haven't been comprehensive enough to completely rule out such a connection. At the same time, vaccinated children don't appear to have a higher rate of allergies and asthma than unvaccinated children.
Meanwhile, there's the very real concern about infectious disease. A child's immature immune system isn't capable of fighting off serious and potentially fatal diseases such as measles and meningitis. That's why it's so important for your child to be vaccinated early. Weighing the very real risk of contracting one of these diseases against any possible risk from the vaccines makes it clear that the benefits of vaccinating your child far outweigh the risks.