More than 300 people have died from the new pandemic swine flu virus, U.S. health officials said on Friday, but they said the virus was so widespread they were ceasing the official count.

The U.S. Centers for Disease Control and Prevention said 43,771 cases of H1N1 influenza had been officially confirmed, with 302 deaths.

The pandemic spread globally in less than two months and has infected people in 160 countries, killing 800 people, the World Health Organization said. The WHO numbers do not include the latest CDC count.

Health experts say millions have likely been infected worldwide, but doctors can only test a fraction of suspected cases. Flu tests are expensive and unreliable and confirming H1N1 swine flu is difficult.

Health officials are now working with companies to test and make a vaccine against H1N1 to be delivered alongside seasonal influenza vaccines.

Also Friday, the CDC said that all U.S. children aged 6 months to 18 years should get a seasonal influenza vaccine every year.

The CDC’s Dr. Anne Schuchat said the agency was strengthening recommendations for children to get the vaccination against seasonal influenza, especially with fears that the new H1N1 virus will be added to the already expected burden of seasonal flu.

WASHINGTON (Reuters)