Adjuvanted and non-adjuvanted H1N1 vaccines safe for pregnant women, say Canadian experts

After discussion with the Public Health Agency of Canada, and based on the evidence for other adjuvanted vaccines as well as experience around the world to date with the adjuvanted H1N1 vaccine, Canadian experts say that both the adjuvanted and non-adjuvanted H1N1 vaccines are safe for pregnant women.

Yesterday in Ottawa, Health Minister Hon. Leona Aglukkaq announced the approval of the adjuvanted H1N1 vaccine which has been judged to be both safe and effective. Provinces and territories will start rolling out their vaccination programs in a matter of days.

An adjuvant is a substance that helps stimulate the body's immune response; it helps boost and speed up the body's ability to fight a virus. It is a natural product made of fish oil, water and vitamin E. While it is the first time these substances are being used in an influenza vaccine, these adjuvants have been used in other vaccines for decades. Countries around the world are stating that both types of H1N1 vaccine are safe, even for pregnant women.

"Women should be provided with the option to receive either H1N1 vaccine based on facts, not fear about safety. More important than the decision about which H1N1 vaccine a pregnant woman should take is the decision to get vaccinated, regardless of the vaccine type selected," said Dr. Michel Fortier, President of the Society of Obstetricians and Gynaecologists of Canada.

Considerations for pregnant women when it comes to which H1N1 vaccine to choose are: - The amount of viral inoculate required to protect an individual: The adjuvanted vaccine includes 4 times less viral material than the non- adjuvanted vaccine. - The number of doses required to achieve immunity: One single dose of the adjuvanted vaccine and possibly multiple doses of the non- adjuvanted vaccine. - The potential for cross-protection against mutations of the virus: The adjuvanted vaccine has a greater likelihood for cross-protection against mutations.

Safety

The adjuvant used by GSK has been tested in approximately 45,000 people around the world and has been evaluated by Health Canada and other regulatory authorities as part of the review of the H5N1 vaccine in the pre-pandemic period. No significant safety concerns regarding the use of the adjuvanted vaccine were detected.

In June 2009, the World Health Organization (WHO) held consultations on the safety of adjuvanted influenza vaccines to review and discuss known and theoretical safety concerns and prospective vaccine safety evaluation. The outcome - no significant safety concerns or barriers to evaluating or using adjuvanted vaccines for the current H1N1 virus were raised.

All evidence suggests that adjuvanted vaccines are just as safe as non-adjuvanted vaccines. The WHO's Strategic Advisory Group of Experts (SAGE) recommended in July that pregnant women should receive non-adjuvanted vaccine where possible, but that an adjuvanted vaccine could be used if necessary.

Dr. Butler-Jones stated that "vaccination is truly the best defence for mother and baby from the potentially devastating effects of the H1N1 virus. The perceived risks associated with either H1N1 vaccine are clearly outweighed by the expected benefits of receiving the vaccine."

SOGC Recommendations for Pregnant Women

Vaccination

The SOGC recommends that all pregnant women over 20 weeks gestation and those less than 20 weeks with underlying risk conditions be vaccinated against H1N1 as soon as a vaccine is available, whether or not it includes an adjuvant. In areas where H1N1 flu rates are high or increasing, health-care providers should offer immediate vaccination with adjuvanted vaccines and not wait for non-adjuvanted vaccines which may only be available in November.

Antiviral Prescriptions

The SOGC recommends that each pregnant woman be given a prescription to be used only if H1N1 symptoms appear. Antivirals should not be used for prophylaxis. Women and their families should be aware of serious symptoms of H1N1, leading patients to seek emergency care.

Posters, Information Tear-Out Sheets

Public information materials about H1N1 and pregnancy have been produced and will be mailed to health-care providers this week. If by the end of next week, information materials have not yet been received, providers are invited to notify the SOGC.