H1N1 vaccine was 93 percent effective during 2009 pandemic

A new study by Canadian researchers showed that a single dose of the H1N1 swine flu vaccine was 93 percent effective during the 2009 pandemic.

Canadian scientists looked at 552 patients in order to gauge whether or not the vaccine, known as the AS03-adjuvanted pandemic H1N1 vaccine, was capable of providing complete protection in most cases, HealthDay News reports. The patients they looked at had flu-like symptoms and visited clinics in four Canadian provinces between November 8 and December 5, 2009.

Pandemic H1N1 was found in 209 of the patients, or 38 percent. Two of the patients, or one percent, had received a single dose of the vaccine at least two weeks before becoming ill, compared with 58, or 17 percent, of patients that did not become ill.

The researchers said the findings showed, in the end, 93 percent effectiveness, according to HealthDay News.

The research was led by Danuta Skowronski at the British Colombia Center for Disease Control in Vancouver.

The findings of the study are not limited to patients in Canada, HealthDay News reports. They can be applied to all countries where the vaccines are used. The researchers hope they will help in the development of other vaccine options.

One limitation of the study concerns age. Most of the patients in the study were under the age of 50, so more research is needed on how the vaccine works in the elderly.

The study has been published in the online edition of BMJ.