Inside the historic, 1740-built Stella Maris Hall at the University of New England, professor Meghan May – surrounded by beakers, microscopes, vials, bacterial cultures and other pieces of laboratory equipment – is researching pertussis, a preventable disease that’s making a comeback in Maine.

The life-threatening disease afflicts more Mainers per capita than any other state in the U.S. – eight times the national average – with 446 cases in Maine last year. Pertussis is a bacterial infection that produces a violent cough that can trigger vomiting and exhaustion. The cough can linger for up to 10 weeks and is treated with antibiotics.

May said the research might lead to an improved vaccine, which would help not only Mainers but thousands across the country who have contracted pertussis, often called whooping cough. The disease was primarily spread by unvaccinated populations, causing the vaccine not to be as effective as it could be. Now, more vaccinated people are getting pertussis because the bacterium that causes the disease has mutated, May said.

She said unvaccinated people transmitting the disease was a major reason the mutation happened – probably emanating from about 15-20 years ago – and now certain strains of the bacteria have become more common and can infect vaccinated people.

A research paper by May, assisted by UNE students, spells out how and why the pertussis bacterium has mutated. The research is expected to be published in a scholarly journal this spring.

“We don’t have the capability here to make a vaccine, but hopefully this research will provide a road map if anyone wants to do so,” said May, a professor of biomedical sciences who works at the university’s Biddeford campus.


Meghan May, an associate professor at the University of New England, says she hopes her research provides a road map to a better vaccine for pertussis. Brianna Soukup/Staff Photographer

Pertussis is widespread in Maine, with 446 cases in 2018 and 95 cases through the first two months of 2019. Pertussis this year is tracking ahead of 2018, when there were 40 cases through February. Several schools have reported outbreaks since last fall, including in 2019 four cases at Falmouth High School, five at Thornton Academy and four cases at Great Salt Bay Community School in Damariscotta, according to the Maine Center for Disease Control and Prevention.

Alannah Shevenell, 16, a Thornton Academy sophomore who is immune-compromised, was one of the students at her high school who caught pertussis in January. Shevenell is immune-compromised because of the anti-rejection medications she takes after a six-organ transplant she received at age 9 to combat an aggressive, malignant tumor. She is now cancer-free, but vulnerable to infectious diseases that are entirely preventable if enough people got their vaccinations.

“It felt like my throat was closing and I could barely breathe,” said Shevenell, who had to be hospitalized overnight at Maine Medical Center in January for pertussis. She recovered, but was out of school for two weeks and coughing for six weeks. At the disease’s peak, she was coughing uncontrollably for hours at a time, she said. People who are immune-compromised are at a much greater risk of contracting infectious diseases, and having those diseases cause hospitalizations or worse.


The Maine Legislature is considering a bill that would eliminate philosophic and religious exemptions that currently allow parents to forgo vaccinations for their children by checking a box on a form.

If the bill passes, the only way unvaccinated children could attend a school or day care in Maine is if they received a medical exemption. Medical exemptions, such as for children with leukemia or other diseases, are extremely rare and made up only 0.3 percent of immunization opt-outs. Maine had the seventh-highest rate of parents opting their kindergarten students out of vaccines in the nation in the 2017-18 school year. Five percent of all kindergartners – representing about 600 students – were opted out for philosophic or religious reasons, and Maine has been consistently among the worst states in the nation for parents choosing to forgo vaccines for their schoolchildren.


Meanwhile, Maine’s pertussis rate is the highest in the nation, and more than eight times the national average. In 2018, there were 13,439 pertussis cases in the United States.

In Maine, the pertussis rate was 33.16 cases per 100,000 population in 2018, the worst in the country, compared to the national average of 4.13 cases per 100,000, according to the U.S. Centers for Disease Control and Prevention. The state with the second-worst pertussis rate was Idaho, at 22.66 cases per 100,000.

May said it’s not clear why Maine’s pertussis rate has skyrocketed, but large pockets of unvaccinated schoolchildren could be a contributing factor.

In more than 30 elementary schools across Maine, 15 percent or more of kindergarten students entered school without required vaccinations. That rate concerns pediatricians because if 5 percent or more of a population is unvaccinated, then herd immunity is weakened. Herd immunity is the protection provided to immune-compromised people, such as babies or those with weakened immune systems, by having nearly everyone vaccinated, which prevents the diseases from circulating.


Dr. Alyssa Goodwin, a Brunswick pediatrician, said the increase in pertussis cases and in the number of unvaccinated children are alarming trends.


Goodwin said last year she had a 2-month-old infant at her office with pertussis who needed to be hospitalized at Maine Med for several days. The baby – who was too young to be vaccinated for pertussis – recovered, but the illness was a jarring reminder of how dangerous the disease can be, she said.

“It was really dramatic. The baby had a staccato cough and was turning blue. We called 911 right away,” Goodwin said.

May, the UNE professor, said she was inspired to do her research – which took about three months to conduct last summer – knowing that the preventable infectious disease is returning to Maine at near-unprecedented levels. The worst year for pertussis in the past decade was 2012, when Maine had 737 cases.

Resistance to vaccination has created a movement that is rooted in myths and conspiracy theories about vaccines, including untrue claims that they cause autism or frequently lead to injuries. Injuries are possible but extremely rare. For example, severe allergic reactions to the measles vaccine occur three to four times for every 10 million doses given, according to the American Academy of Pediatrics.

A one-time school nurse, Hannah Goss of Gray holds her 6-month-old son, Stewart, as he is vaccinated for pertussis last week at a pediatrician’s office in Brunswick. Ben McCanna/Staff Photographer

Hundreds packed a legislative committee hearing on March 13 at the State House Complex in Augusta to argue for and against the vaccination bill. If approved, Maine would join California, West Virginia and Mississippi as the only states to ban all non-medical exemptions for school-required vaccines. In Maine, the bill would also apply to day care facilities.

Hannah Goss, of Gray, brought her 6-month-old, Stewart, to Goodwin’s pediatric practice in Brunswick last week for her baby’s diphtheria, tetanus and pertussis shot and other vaccines.


Goss, a former school nurse in West Bath and Richmond, said school nurses have to constantly try to persuade parents to vaccinate, when it should be mandatory for school entrance.

“There are absolutely a lot of people just checking the box (for philosophic or religious exemptions),” Goss said. “You try to educate, but some people were so against it you couldn’t get through to them.”


Anti-vaccination advocates often blame the pertussis vaccine’s less-than-perfect effectiveness for the rise in pertussis cases. The vaccine is 71-85 percent effective at preventing the disease, according to The Cochrane Database of Systematic Reviews, a scholarly journal.

May said that while the vaccine could be better, pertussis spreads much more easily among unvaccinated populations. The vaccine protects against hundreds of strains, but May said there are several strains – it’s difficult to pinpoint how many – that can overwhelm the vaccine and the body’s immune system.

“Unvaccinated children are more likely to contract pertussis and have more severe disease than those who are fully vaccinated,” according to the U.S. CDC.


The agency reports that of those who contracted pertussis between the ages of 6 months and 6 years in 2018, 59 percent were either unvaccinated, their vaccination status was unknown or they had not received all recommended doses, while 41 percent were fully vaccinated.

May said in Maine, it could be that the predominant strains circulating are the ones that can circumvent the vaccine, which could be a reason why Maine’s rate is so high.

The current pertussis vaccine replaced a more effective vaccine that was shelved in 1992, in part because of side effects but also because of concerns about severe complications, such as brain injuries and epilepsy. The injuries occurred about 50 times out of every 15 million immunizations, but scientific studies found no causal link between the injuries and the vaccine.


The Journal of the American Medical Association in 1990 referred to any connections between the pertussis vaccine and brain damage as a “myth,” but the vaccine was nonetheless replaced in 1992, partly because of the scare and partly because the vaccine was more likely to cause side effects such as fevers, swelling and rashes. An estimated 10 to 50 percent of those getting the vaccine were experiencing common side effects, according to the World Health Organization.

Scientists have also discovered that the current vaccine has waning effectiveness – which is why a middle school booster shot is recommended – and overall does not provide as much protection against pertussis as the original vaccine, which was developed in the 1930s.


May said the medical community could return to the original vaccine, but there may be resistance to do so because of the side effects. Or it could improve the current vaccine so that it provides better protection against different strains of pertussis.

May said the mutation occurs much more slowly than the influenza virus, for instance, which is why the flu vaccine has to be altered every year and why the flu vaccine is not as effective as other immunizations. She said because pertussis mutates at a much slower pace, scientists can develop an improved vaccine and it may not have to be altered for many years.

And if vaccination coverage improves in the United States, that will also help the pertussis vaccine’s effectiveness, May said. She said if vaccination rates don’t improve, a replay of what is happening now – bacterial mutations that sidestep vaccines – will be more likely in the future.

“If you don’t have unvaccinated people spreading the diseases, that bacterial evolution would never be allowed to occur, or would be occurring much more slowly,” May said.

Before wide use of the pertussis vaccine, the U.S. CDC estimates there were about 250,000 cases in the United States per year, which dropped to near zero from the 1960s through the 1980s, usually a few thousand or less per year. Since the original vaccine was replaced, pertussis numbers have slowly risen, peaking at 48,000 cases in 2012, but in most years since 2010 pertussis cases in the U.S. have been between 10,000 and 20,000 cases per year.

Maine was one of the last states to include the middle school booster shot on its list of school-required vaccines in the 2017-18 school year, but May said it’s difficult to determine how that’s impacting the number of pertussis cases, if at all.


The Maine CDC is also closely examining why pertussis is widespread in Maine.

“We don’t yet have sufficient evidence to explain why rates in Maine continue to be high compared to the national average or why they’re higher in specific counties, but we do know that pertussis is incredibly infectious. We continue to work with federal CDC to follow the most up-to-date prevention and control recommendations,” said Emily Spencer, spokeswoman for the Maine CDC.


Shevenell, the Thornton Academy sophomore who was hospitalized with pertussis, went through a grueling experience just to stay alive, said her grandmother and adoptive mother, Debi Skolas, with doctors transplanting her stomach, pancreas, spleen, liver, small intestine and one-third of her esophagus in 2011 at Boston Children’s Hospital, to battle a rare form of sarcoma cancer.

To think that her life could be threatened by diseases that are entirely preventable is maddening, Skolas said.

“She went through so much just to be here,” Skolas said. “I think people who are against vaccinations are incredibly selfish. I can’t even grasp what they are thinking.”


Shevenell sings in the choir and enjoys French class, and is living as normal a teenage life as possible. She is extremely fastidious about washing her hands or using antibiotic soap – she got Purell in her Christmas stocking. She never touches elevator buttons and flushes toilets with her foot.

And she misses school more than most students because she’s susceptible to illness.

“It’s annoying to miss so much school. It makes it hard to keep up,” Shevenell said. But Shevenell has learned to adapt and make the best of things.

Those testifying against the bill argued that it’s the parents’ choice to make decisions on whether to vaccinate, and that the law would infringe upon personal liberty.

Skolas said when a medical decision is made that doesn’t affect others, in those circumstances parental choice should be respected. But she said Shevenell has a right to go to school safely, and the line should be drawn when refusing to vaccinate endangers the well-being of others.

“To not vaccinate because of something you read on the internet is having an extreme sense of entitlement. People should want to protect other kids in the community,” Skolas said.


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