Risk factors, vaccines’ role and what else to know as a whooping cough outbreak grows in Anchorage

In recent days, the Anchorage School District has confirmed cases of pertussis, a highly contagious, vaccine-preventable respiratory illness, in at least six schools.

Statewide, pertussis is leading to hospitalizations and even the death of an infant. Here’s what medical experts Kathy Bell, a nurse and the head of the Anchorage School District’s health services unit, and state epidemiologist Joseph McLaughlin say Alaskans should know about pertussis:

What’s pertussis?

Pertussis is a contagious bacterial respiratory illness that leads to long, sustained bouts of coughing so severe that it can cause vomiting. A distinctive “whooping” sound that coughers make when struggling for breath is the reason for the illness’s other name, whooping cough. Most children receive immunizations against pertussis as babies and children.

What’s happening now?

Alaska is in the midst of a pertussis epidemic. So far, the state has recorded 234 cases this year, according to McLaughlin, an epidemiologist with the Alaska Division of Public Health. By comparison, the year with the most cases before that was 2016, when 149 cases were reported statewide.

The same is happening nationally, McLaughlin said — after several years of low rates during the coronavirus pandemic, the illness is resurgent and circulating. In August, four times as many cases were reported as the same time in 2023, according to the Centers for Disease Control and Prevention. Part of the reason may be the suppression of pertussis during the COVID-19 pandemic due to mitigation measures such as masking and distancing, the CDC says.

“It’s been a while since we’ve really had a sizable epidemic of pertussis, and I think that’s contributing to the large case counts that we’re seeing this year,” McLaughlin said.

Still, the public doesn’t need to brace for the types of mitigation measures seen in the COVID-19 pandemic, including school shutdowns, said Bell, the ASD health director. That’s because pertussis is a known illness treatable with antibiotics and preventable with vaccination, she said.

Who is most at risk?

Infants, especially newborns, are at the most risk from pertussis because they can’t clear secretions and develop trouble breathing, or organ problems, said Bell. In Alaska, one infant has died from pertussis this year, according to McLaughlin. There have been more than a dozen hospitalizations, mostly of children younger than 2 years old, McLaughlin said. Pertussis can cause violent coughing fits that continue for weeks and even months — in some parts of the world, it is known as the “100-day cough” because it can take so long to recover. Older or immunocompromised people can also be at risk for the most severe manifestations of the illness.

What about adults?

Adults can get a booster vaccine that includes protection from pertussis every 10 years. If you want to know whether you have a current pertussis vaccine and when you got it, Bell said you can download the Docket app, which provides access to personal and family immunization records. Immunity wanes over time, but confers “still pretty robust protection five years out,” McLaughlin said.

What role do vaccines play?

As of the end of July, most Alaskans had completed their pertussis vaccine series, though the margins were not large. The state Division of Public Health says:

• For children 19-35 months old, 65% have completed their pertussis vaccine series.

• For children ages 5-6 years, 62% are current with their pertussis vaccine.

• For adolescents ages 13-17 years, 69% received vaccine protecting against pertussis.

• For adults 18 years and older, 65% have at least one pertussis vaccine.

In Alaska, the law requires that families vaccinate their children — including the pertussis vaccine — or apply for a medical or religious exemption to enroll their children in school. Families must sign and notarize a form that says vaccination “conflicts with the tenets and practices of the church or religious denomination.” The state says “personal or philosophical exemptions are not allowed per state law.”

A substantial number of district families sought such exemptions this fall: A total of 1,204 children in the Anchorage School District were not vaccinated for pertussis as of September 2024, according to district data. Of those, 1,018 were religious exemptions, 140 were medical exemptions and 46 were military transfer or child-in-transition exemptions.

The total number of vaccine exemptions was up slightly from the previous school year, when there was a total of 1,182. Students in kindergarten, first or second grade accounted for 35% of the religious exemptions.

“It’s an individual choice. We can’t force people to get vaccines,” said Bell. “But they were developed for a reason.”

Can you get sick if you are vaccinated?

It’s possible to get a breakthrough sickness even if you’re vaccinated, but the symptoms should be less severe, experts say. About half of the kids who’ve tested positive for pertussis in ASD schools have been unvaccinated, Bell said. And more than half of the total number of pertussis cases recorded in the state have been among unvaccinated people, according to McLaughlin.

What should you do if you or a family member get sick?

If you or a family member are sick with symptoms of pertussis, go to the doctor and get tested, experts say — but be aware it can take up to a week to get test results. A doctor will likely start you on a course of antibiotics right away, and you might finish that course of antibiotics before you know whether you indeed tested positive for pertussis, said Bell. People can be contagious for weeks. It’s most important, Bell said, to protect infants, especially those young enough not to have received their first dose of the vaccine.

Early symptoms of pertussis can mirror those of other illnesses going around, including RSV and COVID-19, McLaughlin said, so it’s good to find out for sure.

“It’s a bit challenging right now to be in the middle of a pertussis epidemic when you’ve got all these other viruses that cause very similar symptoms during the beginning of the illness,” he said.