Whooping cough has been on the rise in the United States in recent years, and it may be due to vaccine exemptions.

A study from Harvard University found that communities with high rates of nonmedical vaccine exemptions had a higher incidence of whooping cough (pertussis).

The study also found that the current vaccine for whooping cough appears to lose its efficacy over time.

“When you look at counties that have a lot of pertussis cases, they are the same counties that also have a high level of vaccine exemptions, which suggests an association between the two. Our other finding is that 10- to 14-year-olds who had been vaccinated were as susceptible to pertussis as kids who had never been vaccinated — suggesting that the vaccine’s effectiveness was not long-lasting,” Dr. Barry Bloom, senior author of the study and professor of public health at the Harvard T.H. Chan School of Public Health, said in a press release.

Whooping cough back on the rise

Whooping cough is a highly contagious respiratory illness.

In many people, it causes a severe cough, followed by an intake of breath that sounds like a “whoop.”

The disease is particularly dangerous for children who are too young to be vaccinated.

In the late 1940s a vaccine for whooping cough was introduced, causing a notable decline in the number of diagnosed cases.

In the 1980s and 1990s the rate of whooping cough started to rise, and increased sharply in the mid 2000s.

In 2012, there were 48,000 reported cases of whooping cough in the United States, the highest rate since 1955.

Dr. Eugene Shapiro, a professor of pediatrics at the Yale School of Public Health, said the increase could be due to a few reasons.

“It is complicated because we now have much better tools … to make the diagnosis of pertussis, so detection is much better than it used to be. That is, some of the increase in cases may be due to more testing and better diagnosis,” Shapiro told Healthline.

“Nonetheless, it is clear that the incidence is increasing. Much of this appears to be due to the fact that the acellular vaccines that were introduced because they have fewer side effects than the whole cell vaccine, induce shorter-lived immunity,” he added.

Exemptions linked to disease’s return

Nonmedical vaccine exemptions have been on the rise in some parts of the United States over the past two decades.

These exemptions may be due to religious or philosophical reasons.

Experts also say some parents decline vaccines for their children because they believe they aren’t safe.

“The myth that measles vaccine causes autism has had a deleterious impact on some parents’ opinion of all vaccines. Many think the unfounded accusation was against all vaccines,” Shapiro said.

Dr. Arthur Reingold, professor and division head of epidemiology at the University of California Berkeley School of Public Health, said those who choose not to vaccinate their children are taking a serious risk.

“All parents want what is best for their children, but in my estimation, those who choose not to vaccinate against pertussis are making a bad choice and misjudging the relative benefits of vaccination and the risks,” he told Healthline.

Reingold is not alone in this view.

Dr. James Cherry is a professor of pediatrics and infectious diseases at the David Geffen School of Medicine at the University of California, Los Angeles. He has spent the past 40 years studying whooping cough and vaccines.

He said nonmedical vaccine exemptions are an example of a growing movement of anti-science thinking.

“People believe what they want to believe in spite of the fact they’re presented science, in some cases irrefutable science. This relates to climate change, smoking, and all that kind of stuff,” he told Healthline.

“It is all about politics,” Shapiro added.

He said nonmedical exemptions shouldn’t be allowed at all.

“Officials should rely on science, not misinformation on the internet,” he said.

Vaccine recommendations

Experts concede that the current vaccine used for whooping cough is not without its flaws.

Key among them is that the vaccine only offers short-term immunity. Last year, researchers reported that the whooping cough vaccine starts to lose effectiveness after one year.

Despite this, experts argue that the benefits of having the vaccine far outweigh the risks involved with not having the vaccine.

The Centers for Disease Control and Prevention (CDC) recommends that the best way to protect against whooping cough is through vaccination.

CDC officials say pregnant women should get vaccinated between the 27th and 36th week of pregnancy, so that protection can be passed on to their babies before birth.

“One dose of vaccine will prevent death, so in spite of all the shortcomings, giving our present vaccines is what we should do,” Cherry said.

As for nonmedical vaccine exemptions, Reingold says more needs to be done to prevent such options from being available.

“It saddens me that so many people misjudge the relative risks and benefits … and also that so many people have come to doubt science and experts in general,” he said. “I think it should be as difficult as possible to get a nonmedical exemption … In my view, it is selfish.”