Adjuvanted Vaccine

Q1. What is the difference between an adjuvanted and non-adjuvanted vaccine? An adjuvanted vaccine is a vaccine that includes a substance that boosts an individual's immune system and increases their response to a vaccine. An unadjuvanted vaccine has no "booster" element. Adjuvanted vaccines are included in common vaccines such as tetanus and Hep B. The adjuvant in Canada's H1N1 flu vaccine is made up of natural ingredients such as water, squalene oil and vitamin E.

Q2. When was the last time Canada used an adjuvant in a vaccine? Adjuvants are not new. They have been used for several decades to boost immune response to vaccines. Many of the commonly used vaccines in Canada contain an adjuvant. However, they have not previously been approved for use with influenza vaccines in Canada.

Q3. Are adjuvanted influenza vaccines safe for use? 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 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 of the WHO consultation was that no significant safety concerns or barriers to evaluating or using adjuvanted vaccines for the current H1N1 virus were raised. Clinical studies have been designed to study the risks and benefits of using both adjuvanted and unadjuvanted vaccine against the H1N1 flu virus, and Health Canada and the Public Health Agency of Canada are working closely with other national agencies to implement appropriate post-market monitoring.

Q4. Does an adjuvanted vaccine pose a risk to pregnant women? All evidence suggests that adjuvanted vaccines are just as safe as unadjuvanted vaccines; however there is no safety data for the use of adjuvanted vaccine in pregnant women. 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. Q5. Is the Government ordering non-adjuvanted vaccine? Who will it be recommended for and why? The Government of Canada plans to purchase a small quantity of non-adjuvanted H1N1 flu vaccine (approx. 1.8 million doses) as part of its total order of 50.4 M doses. The purchase of a small quantity of non-adjuvanted vaccine is a precautionary measure for pregnant women as no clinical data of the safety of adjuvanted vaccine in this group is available. In these cases, should a non-adjuvanted vaccine prove to be effective, it may be the preferred option. The WHO has indicated that it has no special concerns about the safety of adjuvanted H1N1 flu vaccines in general. The WHO has also strongly recommended that pregnant women be immunized against the H1N1 flu virus, even if no non-adjuvanted vaccine is available.

 General Vaccine Recommendations

Q1. What are the recommended doses for the use of H1N1 flu vaccine? ADJUVANTED: The recommended doses for H1N1 flu vaccine are as follows:

• All Canadians 10 years of age and older should receive one dose of adjuvanted vaccine; and,
• Children from six months to nine years of age should receive the adjuvanted vaccine in two half-doses, administered at least 21 days apart;

UNADJUVANTED:

• Pregnant women should receive one dose of the unadjuvanted vaccine.
• In cases where the unadjuvanted vaccine is unavailable and H1N1 flu rates are high or increasing, women more than 20 weeks pregnant should be offered one dose of the adjuvanted vaccine.

All data to date indicates that adjuvanted vaccine is as safe as unadjuvated vaccine.

Q2. Who should not receive the vaccine? The following groups of people should NOT receive the H1N1 flu vaccine:

• People who have had a previous anaphylactic (severe allergic reaction) to any element of the vaccine, OR
• People with a hypersensitivity to eggs ( e.g. hives, swelling of mouth and/or throat, breathing difficulty); OR
• People experiencing a high fever, OR
• People who have previously experienced Guillan-Barré Syndrome within 8 weeks of receiving a seasonal flu vaccine.
• The H1N1 flu vaccine is not approved for children under six months.

Q3. How long will it take after I receive the vaccine to have immunity against the virus? After receiving the H1N1 flu vaccine, most people will start to develop immunity within 10 days with just one dose.

Q4. Can the H1N1 flu vaccine be administered at the same time as the seasonal flu shot and/or other vaccines? The H1N1 flu vaccine can be administered along with seasonal influenza immunization and other vaccines. Seasonal and H1N1 flu shots should be given in opposite arms. If an individual receives seasonal flu, H1N1 flu and pneumococcal vaccine in the same day, the seasonal flu shot and the pneumococcal vaccine should be given in one arm, and H1N1 flu vaccine in the other.

Adjuvanted and Unadjuvanted Vaccine Recommendations

Q1. By buying an unadjuvanted vaccine for pregnant women, isn't the government basically admitting there are serious risks with the adjuvanted vaccine? No. There is no evidence to suggest that the adjuvanted vaccine is unsafe. Both vaccines have gone through extensive testing and review before being approved for use. However, there is no evidence available from clinical trials using adjuvanted vaccine in pregnant women or in children aged six months to three years. The adjuvanted vaccine provides much stronger protection, however the Government of Canada ordered 1.8 million doses of unadjuvanted vaccine to offer pregnant women, since adjuvanted vaccine has not been widely tested in this group. The decision to purchase unadjuvanted vaccine for pregnant women is based on a desire to err on the side of caution.

Q2. Why didn't the government just buy enough unadjuvanted vaccine for everyone? The WHO recommended countries use dose-sparing vaccines whenever possible. By developing an adjuvanted vaccine, we use less of the virus material (antigen), allowing us to immunize more people in a timely manner. The use of an adjuvant may also provide cross-protection against virus drift, which is common in influenza viruses. Virus drift occurs when the flu virus begins to begins to change. Adjuvanted vaccine provides a broader spectrum of immunity as it protects against infection and severe disease even when the virus begins to change.

Q3. Is it true that unadjuvanted H1N1 flu vaccine for pregnant women will not be available for weeks after adjuvanted vaccines? Through significant effort the Canadian Government has been able to speed up the delivery of adjuvanted vaccine to provinces and territories. This is a welcome and important development given the adjuvanted vaccine is being used to immunize the vast majority of the population. We are still on schedule to deliver the unadjuvanted vaccine, the one specifically intended for pregnant women in early November. The bottom line is that the time difference is due to a positive development on the adjuvanted vaccine.

Q4. What can I do if I want an unadjuvanted vaccine but I'm not in the groups to receive it? Scientific evidence shows that the adjuvanted and unadjuvanted vaccines are both safe. A small supply of unadjuvanted vaccine has been ordered for pregnant women. The provinces and territories have agreed that this limited supply of unadjuvanted vaccine should be reserved exclusively for this group.

Q5. Is it true that adjuvanted vaccine gives a stronger immunity? If so, why isn't everyone receiving the adjuvanted version? Studies show that even the best unadjuvanted flu vaccines only protect six out of 10 people who get the shot. Experts believe an adjuvanted flu vaccine could boost protection rates to as high as nine in 10. Adjuvanted H1N1 flu vaccine is recommended for everyone over the age of six months, except pregnant women. Unadjuvanted vaccine is recommended for pregnant women since adjuvanted vaccine has not been widely tested in this group. In cases where the unadjuvanted vaccine is unavailable and H1N1 flu rates are high or increasing in the community, women more than 20 weeks pregnant should be offered one dose of the adjuvanted vaccine. All data to date indicates that adjuvanted vaccine is as safe as unadjuvated vaccine. The unadjuvanted H1N1 flu vaccine has a similar formula to the seasonal flu vaccine which has long been recommended for pregnant women. Source: Public Health Agency of Canada www.publichealth.gc.ca