WASHINGTON - H1N1 swine flu is still circulating around the world and still killing people, although it is on the decline everywhere, global health officials said on Friday.

The H1N1 strain is the dominant form of influenza globally, but some seasonal strains are starting to emerge in China and Africa, the World Health Organization reported.

The United States remains one of the hardest hit countries, but many Americans seem unconcerned and most have rejected the vaccine, according to a poll by the Harvard School of Public Health released on Friday.

"Many people believe the outbreak is over and I think it is too soon for us to have that complacency," Dr. Anne Schuchat of the US Centers for Disease Control and Prevention told reporters in a telephone briefing. "This pandemic isn't over yet."

The CDC said nine more children had been reported killed by H1N1 last week. It estimates that as many as 80 million Americans have been infected with swine flu and about 11,000 people have died.

Schuchat said 70 million Americans had been vaccinated against H1N1, which leaves the US government with millions of unused doses because 155 million have been shipped and 229 million ordered from five makers -- AstraZeneca unit MedImmune, Sanofi Aventis, Novartis, GlaxoSmithKline and CSL.

Schuchat said it is easy to be vaccinated now, after severe shortages of vaccine last year, and she urged Americans to get the vaccine.

"It's just impossible for me to say whether we will have a very large peak in disease," she said.

"But we don't seem to be seeing the disappearance of this virus, and we haven't seen the emergence of the seasonal strain ... so I think this virus is going to be finding susceptible people."

The Harvard poll found that 44 per cent of Americans believe the H1N1 flu outbreak is over.

It also found that 40 per cent of parents had gotten the vaccine for their children and 13 per cent more planned to.

Schuchat said only 37 per cent of children who needed to get two doses for full protection had received the second dose.

Sixty-one per cent of the 1,400 adults polled by Harvard at the end of January said they had not received a swine flu vaccine and had no intention of getting one.