U.S. public health expert Laurie A. Garrett said Wednesday that how serious the A/H1N1 influenza situation is going to develop remains unclear.

"We are dealing with the viruses, and viruses evolve, so we cannot predict them," she said. "Is it going to be more dangerous or virulent? Is it going to transform and change, or is it going to stay a fairly mild virus. We really don't know."

Garrett is a Pulitzer prize-winning science journalist and writer of two bestselling books. She was awarded the Pulitzer Prize for Explanatory Journalism in 1996 for a series of works.

She said: "The situation with the virus has remained pretty much as we originally understood. There have not been any major changes so far."

"Right now, the virus does not look that dangerous. But if the virus changes, and takes a more dangerous form, then we have a lot to worry about," she said.

She warned that if animals or humans are infected with both A/H1N1 and H5N1 viruses, then it could be extremely bad as viruses have a chance to exchange their genetic material.

According to Garrett, the A/H1N1 virus is moving into the Southern Hemisphere now. "It could be a bad thing if it reaches large populations of people who are HIV positive as HIV destructs the immune system."

"What we are worried is what happens with the virus in Africa," she added.

While commenting on the awareness of the general public in the United States, Garrett said most people have no idea what a contagion looks like and they've never been through it as it has been so long since America faced a contagion.

"That's one of the reasons we don't have a lot of people reacting by putting on masks," she said.

Speaking of the U.S. government's efforts in preventing the spread of the virus, Garret said it has moved swiftly.

"We've seen a lot of smart reaction. Right now, we can concentrate on the good news that what has been done has largely been successful and so far, we seem to be in very good shape in the United States," she said.

(Xinhua?News Agency May 14, 2009)