Science

H1N1 vaccine safe for pregnant women: specialists

Both forms of the H1N1 vaccine are safe for pregnant women, a group of Canadian doctors says.

Canadian flu cases on the rise

Canada has also ordered about 1.8 million doses of the non-adjuvanted H1N1 vaccine for some pregnant women. ((Canadian Press))

Either form of the H1N1 vaccine is safe for pregnant women, and they should be vaccinated against the virus quickly, Canadian doctors said Thursday.

Dr. Michael Gardam, a director with the Ontario Agency for Health Protection and Promotion, said no side-effects have been reported in connection with the vaccine. However, the dangers associated with the H1N1 virus are serious and well-documented.

"If [pregnant women] get infected with this, they are four to six times more likely to get a serious disease than a woman who is not pregnant," he told CBC News. "That is very real. I would like to focus on the real risk and not things that are hypothetical."

Health Minister Leona Aglukkaq announced Wednesday the approval of one type of swine flu, or H1N1, vaccine — the vaccine containing an adjuvant, which is a substance that stimulates the body's immune response.

Canada has also ordered about 1.8 million doses of the non-adjuvanted H1N1 vaccine, but regulatory approval of that version isn't expected for a week or two.

Pregnant women in Canada were initially told they should wait for a non-adjuvanted version of the vaccine because the adjuvanted version had never been tested on pregnant women.

But on Thursday, the Society of Obstetricians and Gynaecologists of Canada said all evidence suggests that adjuvanted vaccines are just as safe as non-adjuvanted vaccines. There has been no significant safety concerns regarding the use of the adjuvanted vaccine.

"Women should be provided with the option to receive either H1N1 vaccine based on facts, not fear about safety," Dr. Michel Fortier, president of the obstetricians and gynecologists society, said in a written statement Thursday.

The news comes as the number of swine flu cases in Canada is rising significantly.

While Canada's public health agency won't release its most updated numbers until Friday, Donald Low, the medical director of Ontario's public health laboratories told CBC News the number of serious cases has increased sharply in recent weeks.

The last available figures, which combine data until Oct. 10, show a total of 1,541 hospitalized swine flu cases across Canada and 80 deaths.

Non-adjuvanted vaccine available in November

On Wednesday, Canada's chief public health officer, Dr. David-Butler-Jones, recommended giving pregnant women one dose of non-adjuvanted vaccine. If the vaccine is not available and H1N1 rates are high or increasing, women more than 20 weeks into their pregnancy may be offered the adjuvanted version.

Pregnant women with an underlying health condition should talk to their health-care provider about getting the adjuvanted form, Butler-Jones advised, rather than wait for the non-adjuvanted vaccine, which may not be available until November.

The obstetricians and gynecologists society stresses that while this is the first time an adjuvant has been used in an influenza vaccine in Canada, the adjuvant has been used in other vaccines for decades.

A single dose of the adjuvanted vaccine — which contains a natural product made of fish oil, water and vitamin E that helps boost up the body's ability to fight a virus — is needed to achieve immunity in healthy adults. Clinical trials are underway to test how many doses of both types are needed to protect pregnant women, and it's possible that multiple doses of the non-adjuvanted vaccine may be needed.

The adjuvanted vaccine is also more likely to offer protection from mutations in the virus, the group said.

GlaxoSmithKline's adjuvant has been tested in about 45,000 people worldwide and was evaluated by Health Canada and other regulators as part of a review of the H5N1 avian flu vaccine before the H1N1 pandemic started in the spring. No significant safety concerns were raised.

In July, an expert committee at the World Health Organization recommended pregnant women receive non-adjuvanted vaccine where possible but said the adjuvanted version could be used if necessary.

The Society of Obstetricians and Gynaecologists has backed Health Canada's earlier recommendation that pregnant women be given a prescription for antivirals to be used only if H1N1 symptoms appear. Antivirals should not be used for preventive purposes.

Women and their families should be aware of serious symptoms of H1N1, and seek emergency care if these occur.

According to the U.S. Centers for Disease Control and Prevention, emergency warning signs in children are:

  • Fast breathing or trouble breathing.
  • Bluish skin colour.
  • Not drinking enough fluids.
  • Not waking up or not interacting.
  • Being so irritable that the child does not want to be held.
  • Flu-like symptoms improve but then return with fever and worse cough.
  • Fever with a rash.

In adults:

  • Difficulty breathing or shortness of breath.
  • Pain or pressure in the chest or abdomen.
  • Sudden dizziness.
  • Confusion.

Mild flu symptoms include fever, cough, sore throat, sore joints, sore muscles and fatigue.