An effective vaccination program against bird flu would require each human having two shots. Researchers have come up with a suggestion that perhaps the first shot could be given before a pandemic starts – giving people a headstart.

The problem with any current strategy is that full protection would arrive too late. Look at the following sequence and you will see why:

1. In order to create a vaccine we have to wait for a pandemic to start to identify the mutated virus
2. We would then spend several months getting the new vaccine ready
3. Add several more months to make enough vaccines for lots of people
4. Most likely people would need two shots before they had full protection

Having to wait all that time to get full protection after a pandemic commenced would probably mean huge numbers of people getting ill, and possibly dying.

What if people were given the first shot before a pandemic broke out? The first shot would not provide full protection, but would expose the body to a new type of flu. As soon as the pandemic arrived, the second shot could be given much earlier. Even while waiting for the second shot, people’s bodies would be that bit better at pulling through mutated bird flu. Scientists from the University of Rochester are calling this strategy the Prime and Boost method.

If their research is right, frontline workers, such as doctors, nurses and other staff could be given a shot well before the arrival of a pandemic. In fact, the prime shot could be given to anyone.

Study leader, Dr. John Treanor, said this method would allow for as many people as possible to be prepared in advance.

In this study, the scientists looked at 37 people who were given an experimental bird flu vaccine in 1998 – this vaccine was made from the first H5N1 to jump from birds to humans in 1997 in Hong Kong. Seven years later they each received a booster shot aimed at another H5N1 virus strain – a strain found in Vietnam in 2004. These people were compared to people who received their first shot in 2004 targeted at the Vietnam H5N1 virus strain.

The scientists found that those who had been first vaccinated in 1998 and then again in 2004 were better protected than those who just received one shot in 1994. Over double the number of people who received two shots had an effective immune response, compared to those given just one shot.

The team presented their findings at the annual meeting of the Infectious Diseases Society of America.

— University of Rochester Medical Center (article)
— Infectious Diseases Society of America

Written by: Chrisitan Nordqvist
Editor: Medical News Today