The Mississippi State Department of Health issued an alert Wednesday that cases of pertussis, or whooping cough, are climbing in the state. 

The year-to-date number of cases in Mississippi ballooned to 80 as of July 10. That compares to 49 cases in all of 2024. 

No whooping cough deaths have been reported. Ten people have been hospitalized related to whooping cough, seven of whom were children under 2 years old. 

Cases have largely been clustered in northeast Mississippi. The region accounts for 40% of cases statewide. 

The nation has also seen rising rates of whooping cough, though cases have been climbing less steeply than in Mississippi. About 15,000 whooping cough cases have been reported nationwide this year, according to the Centers for Disease Control and Prevention.

The highly contagious respiratory illness is named for the “whooping” sound people make when gasping for air after a coughing fit. It may begin like a common cold but can last for weeks or months. Babies younger than 1 year are at greatest risk for getting whooping cough, and can have severe complications that often require hospitalization. 

Whooping cough cases fell in Mississippi after the COVID-19 pandemic began, but have since rebounded. This is likely due to people now taking fewer mitigation measures, like masking and remote learning, State Epidemiologist Renia Dotson said at the state Board of Health meeting July 9. 

The majority of cases – 76% – have occurred in children. Of the 73 cases reported in people who were old enough to be vaccinated, 28 were unvaccinated. Of those 28 people, 23 were children. 

“Vaccines are the best defense against vaccine preventable diseases,” State Health Officer Dr. Dan Edney said after the State Board of Health meeting.

Mississippi has long had the highest child vaccination rates in the country. But the state’s kindergarten vaccination rates have dropped since a federal judge ruled in 2023 that parents can opt out of vaccinating their children for school on account of religious beliefs. 

The pertussis vaccination is administered in a five-dose series for children under 7 and booster doses for older children and adults. The health department recommends that pregnant women, grandparents and family or friends that may come in close contact with an infant should get booster shots to ensure they do not pass the illness to children, particularly those too young to be vaccinated. 

Immunity from pertussis vaccination wanes over time, and there is not a routine recommendation for boosters. 

State health officials also encourage vaccination against other childhood illnesses, like measles. While Mississippi has not reported any measles cases, Texas has had recent outbreaks. 

The Mississippi Health Department offers vaccinations to children and uninsured adults at county health departments. 

Correction 7/16/25: This story has been updated to reflect that the age of the seven hospitalized children is under 2 years old.