Waning immunity behind whooping cough outbreak in N.L., top doctor says

An outbreak of pertussis — otherwise known as whooping cough — is percolating in Newfoundland and Labrador, health officials say.

In a news conference Tuesday, the province's top doctor said the Department of Health has identified 230 cases of whooping cough so far in 2024.

Normally the province would see between three and five cases a year.

"We now really have to say this is a provincewide outbreak," said Dr. Janice Fitzgerald, chief medical officer of health, due to the sheer number of cases in recent months.

Pertussis is a contagious respiratory infection that can lead to severe complications. Symptoms may start with a runny nose, mild fever and cough, and progress to episodes of severe, prolonged coughing, often accompanied by a distinctive "whooping" sound during inhalation.

Symptoms can last from weeks to months, and infants are at the highest risk of complications, such as pneumonia and seizures.

Pertussis can be treated with antibiotics, but the province is encouraging adults and children to stay up to date on pertussis vaccines. The vaccine is regularly offered to the following groups:

• All children at two, four, six, and 18 months of age.
• All children between four and six years of age.
• All children in grades 8 and 9.
• Pregnant people between 27 and 32 weeks gestation for each pregnancy.
• Adults at least 10 years from their school-age dose.

"Pertussis starts like any regular cold, really," Fitzgerald said. "That cough may get worse as time goes on, so certainly it can get quite severe."

Coming down with a cold that doesn't seem to improve over time may indicate a pertussis infection. In that case, Fitzgerald says, patients should inquire about a pertussis test.

The majority of the pertussis cases this year — 190 of them — are in eastern Newfoundland. Many of them are preteens, Fitzgerald said.

"We know that the pertussis vaccine wanes a little bit as time goes on. So we're starting to see that in that junior high age group," she said.

A decline in shots isn't behind the outbreak, she added.

"Our province is exceptionally good at availing of childhood vaccinations," she told reporters. "I think really what we're seeing is waning immunity."

N.L. Health Services is considering moving its Grade 9 booster shot to an earlier age group to combat that, she said.

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