Your questions answered on the H1N1 Vaccine

We asked Dr. Gerald Evans from KGH to field your questions about the pH1N1 Flu. This time, the topic is about the pH1N1 vaccine. Dr. Evans is an Associate Professor in the Departments of Medicine and Microbiology & Immunology, and an Assistant Professor with the Department of Pathology, at Queens University.

The surge of pH1N1 cases is declining, should people still get the vaccine?

Yes, you should get vaccinated if you have the opportunity. The reason is not simply protecting yourself over the next month or two, but principally because this virus is almost certainly going to become part of our seasonal flu over the ensuing years – that’s what happens with influenza viruses. When new ones get introduced they supplant the old ones and replace them. That’s what happened with pH1N1. We saw it in the southern hemisphere where by the end of the flu season it had become the only circulating influenza virus. Getting the vaccine is important because you want to protect yourself for the future. Yes, it will be part of the next seasonal flu vaccine, but there’s nothing to say we won’t have another wave of pH1N1 this winter when we typically have seasonal flu.

Now that you’ve seen pH1N1 in action, what have you learned about it?

This is an amazingly easy-to-transmit virus, especially among children and adolescents. For kids, there is a two in three chance that if they haven’t had pH1N1, aren’t vaccinated and they are exposed to somebody who has pH1N1 that they’re going to get it. For adults, it’s a lot more like regular flu. It’s about a one in four chance. Although we had models of pandemic flu, the speed that pH1N1 spread and the number of cases we are seeing is actually above what we planned for.

What is a Vaccine?

Vaccines have been extraordinarily useful and have revolutionized the treatment of infectious diseases. The classic vaccine was for smallpox. It was first made in the late 1700s and was simply inoculating with a different virus which is similar to smallpox – in this case cowpox. This was based on the observation that milkmaids who got cowpox rarely ever get smallpox, suggesting some sort of cross-immunity. That’s an example of a live virus vaccine with a completely different virus that happens to protect you against the one you are trying to prevent.

Since then, many different vaccine strategies have been developed. One is to give patients a “killed” virus, which is what our pH1N1 vaccine is made from. This is a vaccine that contains virus that has been killed and disrupted with chemicals or heat. People who receive it will make antibodies against those components of the virus, which will subsequently protect you against the actual virus infection. Vaccines can also be made to protect individuals from toxins, such as tetanus. And finally, there are live virus vaccines such as measles, mumps and rubella. Those are called attenuated live virus vaccines. They are made from the actual virus that causes the disease but they’ve been made weaker and so are unable to cause an illness but make the vaccine recipient produce protective antibodies against the real or wild-type virus. 

What is an adjuvant and why is it used in the pH1N1 vaccines?

Adjuvants are simply chemicals or substances which are added to vaccines to boost the person’s immune response to the vaccine. The classic one was alum. We also know that adding certain types of inactivated toxins will also help. The tetanus shot actually has a little bit of diphtheria toxin in it, which acts in a way to boost the immune response to tetanus toxin. In the case of the pH1N1 vaccine, it is a newer adjuvant called ASO3. It has been used in the vaccine that was developed for the Avian Flu from Southeast Asia and has been used in other vaccines in Europe. Adjuvants do not contain mercury. The mercury issue in vaccines comes from the fact that a number of vaccines have used a preservative that keeps the vaccine sterile. One of them is called Thimerosal, which has a small amount of mercury in it. Without it multi-dose vials of vaccines might become contaminated. You get more mercury from eating a tuna fish sandwich than from a single dose of vaccine.

What can you do to make someone with pH1N1 comfortable when they become sick?

It’s all the usual comfort measures that your mom told you about and gave to you when you were a kid. In my Mom’s case it was chicken soup, ginger ale and lots of rest. People who are sick with the flu don’t want to do anything other than rest. They want lie down and lay low. For controlling fevers, you can give something like acetaminophen. The fever, cough and muscle aches are part of what makes you feel bad with the flu.