A virologist tests samples for signs of swine flu at Sydney's Prince of Wales Hospital ... infections may be as high as 100,000 in the U.S. alone
Credit: Torsten Blackwood/AFP
PARIS: Swine flu infections may be 20 times higher than so far detected, but the chances of a common vaccine for all strains are high after a study found they react to antibodies in the same way.
Published in the U.S. journal, Science, the study says the various A(H1N1) virus strains have probably been circulating unnoticed in pig populations for some time, and calls for more careful monitoring of swine populations.
It confirms that the new pathogen originated with pigs, and is a mix of a previously known virus that already contained avian, swine and human genetic segments with two other genes from Eurasian swine viruses never detected outside Asia before.
Understanding origins
Understanding the origins of the novel A(H1N1) virus could help scientists prevent the pathogen from emerging in a new - and potentially more virulent - form, the researchers said.
"These findings are critically important for our global public health," said Nancy Cox, chief of the influenza division of the U.S. National Centre for Immunisation and Respiratory Diseases in Atlanta, Georgia, and a co-author of the study.
"The new A(H1N1) viruses are antigenically similar, that is, they react to antibodies in a similar way," she told journalists in a teleconference. "This makes our job of coming up with a reference candidate vaccine virus much, much easier."
Differences with seasonal flu
Cox cautioned, however, that the swine flu was very different than seasonal flu, meaning that vaccines designed for the latter probably would not work against both.
The number of confirmed swine flu infections worldwide topped 11,000 Friday, including more than 85 deaths, according to the World Health Organisation.
A total of 11,168 infections had now been detected in 41 countries. The United States had 5,764 cases, with nine deaths, while Mexico had 3,892 infections, including 75 deaths. Canada had 719 cases, with one death.
