In fall 1997, two influential professional magazines featured articles asking the question: Has the decrease of infectious diseases in childhood through the mass use of vaccines been replaced with an increase in chronic diseases such as diabetes and asthma? The Economist, a prestigious international magazine read by world leaders in government, business and public policy, and Science News, a magazine read by both health care professionals and the general public, explored the reported links between vaccines and chronic diseases in their November 22, 1997 issues.
Infections in Childhood Protect Against Chronic Disease - In an article entitled "Plaqued by Cures," The Economist acknowledged that trying to prevent or treat an infectious disease can have profound effects on the pathogenic organism that causes it, pointing to the evolution of antibiotic-resistant strains of bacteria and the appearance of mutant viruses able to evade vaccines. The article went on to explain the "hygiene hypothesis," which holds that exposure to infections in childhood may prevent chronic disease later in life and that "intervening in infections may have undesireable effects on the hosts - that is, on people - as well as on the pathogens themselves."
The article in The Economist reviewed a number of new medical studies around the world which back up the hygiene hypothesis. In a study in Guinea-Bissau, researchers found that children who had not had measles disease were significantly more likely to suffer from allergies including asthma, eczema and hay-fever. In Italy, researchers found that children who were exposed to hepatitis A disease were less likely to suffer from allergies. And a study published in a November 1997 Archives of Disease in Childhood showed that children in England who had suffered a severe respiratory infection in childhood were less likely to acquire Type 1 diabetes.
One theory being forwarded to explain why recovery from naturally occurring childhood diseases is important is that the human immune system has evolved over tens of thousands of years to respond to and be strengthened by attacks from viruses and bacteria. Depriving the developing immune system of naturally occurring infections in childhood may cause the immune system to eventually attack itself, which is what happens in autoimmune diseases like asthma and diabetes.
Unvaccinated Children Have Less Asthma - In an article entitled "The Dark Side of Immunizations?," Science News reviews new reports by researchers that show that vaccinated children have a higher incidence of asthma and diabetes than do unvaccinated children. Science News reports that a study by researchers at the Wellington School of Medicine in New Zealand found that unvaccinated New Zealand children report fewer cases of asthma than vaccinated children.
Another study by New Zealand researchers published in the November 1997 Epidemiology analyzed the health of 1,265 people born in 1977. Of these, 23 didn't get any childhood vaccinations and none of them suffered childhood asthma. Among the 1,242 who got polio and DPT shots, more than 23 percent later had episodes of asthma.
Science News adds that a 1994 survey of 446 British children, most of them eight years old, showed that 91 received no vaccinations in early childhood. Only one child out of 91 got asthma. About 11 percent of the other 355 children who had been vaccinated with pertussis and other vaccines had asthma.
The article goes on to note that animal studies indicate that an absence of contact with naturally occurring viruses increases the risk of diabetes and that research in humans suggest that some childhood infections may prime a person's immune system to fight off asthma.
Howard L. Weiner, an immunologist at Harvard Medical School in Boston, is quoted in the article as saying that immunization skews the activity of the immune system and "If a person has a tendency toward a disease at a certain age, a vaccine might ... make [him or her] more susceptible later, when other challenges come along." He added, "It's logical that there might be some immune manipulation that happens in childhood that might have a positive or negative effect on these diseases."