AHS declared the outbreak last Thursday, when the health authority reported 16 confirmed cases of the disease spanning Lethbridge County, Coaldale, Taber, Vauxhall, Grassy Lake and Bow Island.
A case had been identified as far west as Fort Macleod, with no cases confirmed in Pincher Creek, Dr. Vivienne Suttorp, AHS South Zone’s medical officer of health, told Shootin’ the Breeze the next morning.
“We suspect there are many more (cases) out there,” Suttorp cautioned, noting that whooping cough is “typically under-reported” because infected people tend to show symptoms associated with other respiratory diseases like Covid-19 and the seasonal flu.
Whooping cough can lead to pneumonia and encephalitis, especially in kids under two. But it’s easily preventable through a safe, reliable and easily accessible vaccine against Bordetella pertussis, the bacterium that causes the disease.
An unvaccinated baby girl in southern Alberta died of whooping cough in 2012. The vaccine is not approved for newborns, but Suttorp said babies take on their mother’s immunity if expecting moms get vaccinated in their third trimester.
Herd immunity set in when communities hit 98 per cent vaccine coverage. Immunization rates in some south zone communities dropped from 86 per cent in 2008 to 23 per cent in 2021, according to Alberta Health statistics quoted by Suttorp.
Vaccination rates in Pincher Creek held at an annual average of roughly 83 per cent over the same period. For comparison, coverage was just over 90 per cent in 2008, falling just under 70 per cent in 2021.
Rates were generally lower across Crowsnest Pass, which maintained an average annual rate of roughly 75 per cent.
Whooping cough outbreaks tend to hit southern Alberta every three to five years, and Suttorp noted that the current outbreak is “right on time.” But the disease is more likely to persist wherever immunization levels are low.
Suttorp attributes “vaccine hesitancy” to complacency, the need for booster shots, and a lack of trust in vaccines and vaccine providers.
Complacency sets in when parents assume that whooping cough isn’t serious. Small children acquire comprehensive immunity after four doses of the vaccine, and it can be difficult for parents to stay on top of the recommended schedule.
As to the lack of trust, Suttorp noted that vaccine coverage started to dip well before the Covid-19 pandemic, although conspiracy theories claiming that mRNA vaccines are harmful or ineffective likely played a part.
In the meantime, AHS anticipates that the regional outbreak will last for months.
No vaccine is 100 per cent effective, and Suttorp qualified that vaccinated people can develop infections, especially in communities where vaccine rates are low.
Breakthrough infections tend to be much less severe than in people who haven’t had the vaccine, she said.
AHS recommends that people stay home if they develop symptoms or if they come into contact with an infected person.
For more information about vaccinations, including clinic locations, visit AHS’s website at ImmunizeAlberta.ca or the province’s website at myhealth.alberta.ca.
The same information is available through the province’s 24-hour Health Link hotline, 811.