History repeats itself: Diseases of the past back to haunt us

It’s not an exaggeration to say that vaccines have changed the world. Diseases like smallpox have been eliminated worldwide, and the United States remains polio free. Other diseases, such as mumps and rubella, have been reduced by more than 99 percent. Parents don’t have to live with the constant fear that their children will die or be disabled by an infectious disease. Today, at least in the developed world, people are far more likely to die of a chronic condition like cancer or heart disease than from a vaccine-preventable illness.

Still, with the exception of smallpox, these diseases are not gone. Measles cases in the United States spiked to three times their normal levels in 2013, and around the world, the disease kills more than 100,000 people each year.

Why do these preventable diseases still exist?

The answer is partly economic and partly logistical (as it can be difficult to get vaccines to people in the middle of a warzone), but parents’ consciously opting out contributes too.

Some parents have resisted vaccinating their children against measles and other diseases, fearing a purported link between the vaccine and autism, or simply objecting for personal or religious reasons. There is also increasing evidence that these voluntary abstainers are partly responsible for the increase in vaccine-preventable disease outbreaks that everyone thought were relegated to the history books.

All this while study after study have shown that vaccines have no link to autism, and the article suggesting the association has been retracted by the scientific journal the Lancet.

“There are strong feelings on both sides of the debate,” said Scott Lillibridge, M.D., epidemiologist and professor at the Texas A&M Health Science Center School of Public Health and deputy principal investigator and chief scientist for the Texas A&M Center for Innovation in Advanced Development and Manufacturing. “However, people have largely forgotten the devastating effects of these diseases before vaccines existed.”

For example, according to Centers for Disease Control and Prevention (CDC) estimates, in 1952, 3,145 Americans died as a result of polio. Since 1996, that number has been zero. In 1958, 763,094 people in the United States contracted the measles, and 552 died. In 2007, there were 43 measles cases and no deaths.

High immunization rates, particularly in school age children, have a benefit to the community through “herd immunity” and protect those vulnerable members of the population who cannot be routinely immunized for medical reasons, such as in the case with babies in the first months of life. “When vaccination rates are high, there are fewer unvaccinated persons for the virus to infect, which stops a disease from spreading,” Lillibridge said. “In general, we need at least a 95 percent rate of immunization among the population to stop measles from spreading within a community.”

And in this day and age where a person carrying a disease can travel from a place where a disease is endemic to a major American city like New York or Los Angeles in just a few hours, we might not be as safe from these diseases as we think. Just like the measles outbreak of 2014 started with one infected individual, it only takes a single person to spread a disease through an unvaccinated community. This doesn’t only happen in the United States: Europe, which also has plummeting immunization rates, has been suffering from repeated measles outbreaks as well.

“When the risks are so low and the benefits so great, the choice is obvious,” said Lillibridge, who is a 30-year veteran in medical and public health preparedness and previously served as founding director of the CDC Bioterrorism Preparedness and Response Program and who also worked as Special Assistant to the Secretary for the U.S. Department of Health and Human Services for National Security and Emergency Management.

Texas A&M Health Science Center students are trying to spread the word about the importance and ease of vaccinations. In Texas, and most other states, uninsured children can get many vaccines free of charge.

And although experts are optimistic that polio is one infectious disease that might be controlled or eliminated from humans this year, armed conflicts and/or lack of public health infrastructure in Syria, Nigeria and Pakistan are challenging that goal. Many people are concerned that as migrants and refugees flow into Europe, they might also be inadvertently be bringing the disease with them, which can have public health implications.

“It’s important to note that vaccinations protect not only the individual that has been immunized, but also indirectly protects others in the community as well,” Lillibridge said. “Vaccines remain one of the most effective tools we have to protect public health and prevent infectious disease deaths worldwide.”