Flu shot 'not perfect' but still vital for pregnant women, say doctors

A University of Calgary researcher is trying to dispel misconceptions that the flu shot is unsafe for pregnant women.

Only 22% of pregnant women in southern Alberta got vaccine last year

Dr. Eliana Castillo says health care professionals need to do a better job of communicating the importance of vaccines for pregnant women. (Reid Southwick/CBC)

University of Calgary researchers are trying to dispel misconceptions that the flu shot is unsafe for pregnant women by providing them the shot during their regular prenatal checkups. 

Only 22 per cent of pregnant women in Alberta Health's south zone, which includes the Calgary region, got the flu shot last year.

In other parts of the province, that number was as low as 10 per cent.

Shot is not perfect, but decreases risks

"I think a factor is that we have not necessarily made the best job of telling our patients that protecting ourselves means protecting our babies," said Dr. Eliana Castillo, clinical associate professor with the Cumming School of Medicine and consultant with Alberta Health Services.

Castillo said that pregnant women are especially susceptible to influenza. It can increase their chances of landing in the hospital or the intensive care unit, and it can also increase the chances of a pre-term birth or having a baby born smaller than it should be.

"The flu shot, although not perfect, always decreases those risks," she said.

Castillo is part of a program at the Foothills hospital where obstetricians offer flu shots to women at their regular prenatal examinations.

This prevents women from having to book another doctor's appointment, and also gives them a chance to learn about the shot from a doctor they trust that specializes in pregnancy care.

Vaccines only way to protect babies during first few months of life

Data shows that pregnant women are more hesitant about vaccines than non-pregnant women, Castillo says, but it's important for them to know the risks they are taking if they choose not to get vaccinated.

Since babies are unable to be vaccinated against the flu or whooping cough during their first six months of life, the only way to protect them during those first few months is for their moms to get vaccinated while pregnant. 

And, Castillo explained, obstetricians often feel that immunizations aren't their job, but rather can be left to the family doctor or public health care provider. 

So far this season, nine pregnant women have been admitted to the hospital with the flu in Calgary. 

In 2015-2016, only 15 women were admitted across the entire flu season.

"Influenza is serious, it does lead to hospitalizations and sometimes to deaths and that's why it's so important to be immunized," said Dr. Judy MacDonald.

MacDonald added that seniors, pregnant women and children under five were the most likely to be impacted. 

This year's vaccine reportedly hasn't provided good coverage for the main circulating strain, H3N2, which has historically been a difficult strain for which to create a vaccine. But Castillo said that even 10 per cent protection is better than nothing.

"We have to get better at conveying the message that even if the flu shot is not perfect — and there are years like this where it is well, well, well far from perfect — it's the best that we have," she said.

If the Foothills pilot program is a success, it could be rolled out across Alberta.

A total of 1,167,858 doses of the flu vaccine had been administered during the 2017-18 flu season across Alberta as of Thursday, and 31 Albertans who have died have been confirmed to have had the flu.


  • An earlier version of this story incorrectly quoted Dr. Castillo as saying the flu could increase the chances of a "breech birth". In fact, he said "pre-term" birth.
    Jan 12, 2018 8:32 AM MT

With files from Reid Southwick