Mysteries of H1N1

MANY MYSTERIES

The virus has killed 176 people in Mexico and spread to at least 10 other countries but most of the cases outside Mexico have been mild, an observation that has intrigued everyone.

Nobody knows for sure how this virus came to be, which animal passed it to the first human patient and when that occurred.

But experts expect to find out a little more through analyzing its samples and tracking its DNA changes over time.

"The current analysis indicates this is mainly a swine virus, but further whole genome sequencing throughout the pandemic period and comparison with previous purely swine viruses (isolated from pigs) will be able to tell us which genes are mutating to allow pig-to-human transmission and then more efficient human-to-human transmission," said the scientist with the government hospital in Asia.

"If you can sequence full viral genomes at regular time points during the pandemic, you can see how the pandemic strain is evolving with the human pandemic and which genes are evolving in parallel with new clinical and epidemiological developments, for example, say patients now do not get diarrhea as a routine feature of the current virus strain, but later on, they start to develop diarrhea -- which gene mutation may have lead to this new clinical feature?"

The virus, which had never been seen until it turned up in people in Mexico, is designated H1N1, within the same family as the seasonal human H1N1 flu virus. But curiously, the H1N1 component in the current human flu vaccine offers no protection.

"We need a new vaccine (to fight the new flu virus), it only takes one amino acid change in the whole protein makeup of the virus to escape the vaccine," said Itzstein.

The CDC is making available virus samples for manufacturers to make a vaccine as needed.

"We will quickly get hold of the seed of the new flu virus ... and produce a vaccine," Japan's Health Minister Yoichi Masuzoe told a news conference on Thursday.

However some experts doubt if that is practical. A vaccine is not expected to be commercially available until 3 to 6 months after licensing, by which time a pandemic may have entered another phase, or may just be over. The World Health Organization will decide later whether one is needed.

(Copied from science daily dot com)