WASHINGTON (Reuters) - The new pandemic of swine flu has killed 76 children in the United States since it emerged in April and is worsening, U.S. health officials said on Friday.

A child reacts as he receives the H1N1 swine flu vaccine in a nasal spray at Dodge Park Elementary School in Landover, Maryland, October 9, 2009. REUTERS/Jonathan Ernst

But researchers are reporting some good news about vaccines that may smooth efforts to immunize people against the pandemic flu and ordinary flu at the same time.

Although it is not quite at epidemic levels yet, H1N1 is spreading in many states at a time when normally there is little or no influenza, the U.S. Centers for Disease Control and Prevention said.

Several studies reported this week show that most people, including children, who die from swine flu have underlying conditions making them more susceptible, but some who are healthy are also dying, the CDC said.

“We saw a peak of pediatric deaths starting in April, May, June,” the CDC’s Dr. Anne Schuchat told reporters in a telephone briefing. “It’s starting to shoot up again.”

The 76 deaths compare to 68 deaths from seasonal influenza from September 2008 to April 2009, the CDC said. Many of the children who have died had neurological conditions such as muscular dystrophy or cerebral palsy, the CDC said.

The CDC is trying to roll out vaccines against swine flu at the same time as an usually early campaign of vaccinating against seasonal influenza.

Officials predicted some bumps in the road and there have been some, with some counties suspending seasonal vaccination to make room for H1N1 vaccines.

But a new report suggests it may be easier to do this. Trials show that giving an H1N1 shot at the same time as a seasonal influenza shot causes no problems and people are fully protected, said Dr. Anthony Fauci of the U.S. National Institute of Allergy and Infectious Diseases.

Early results from trials of adults show those who got both shots at the same time had good immune responses to the vaccine, Fauci told the briefing.

The CDC said 6.8 million doses of H1N1 influenza vaccine were now available for states to order -- much of it AstraZeneca unit MedImmune’s nasal spray vaccine, which is approved for healthy people aged 2 to 49.

States have placed orders for 3.7 million doses. Orders are placed only when there are hard and fast plans for administering the vaccine.

Many states are vaccinating either healthcare workers or children first against H1N1 -- both are in the CDC-designated “priority groups” for vaccine.

Schuchat said some doctors wrongly believed that healthcare workers should not get the nasal spray but only those working with severely immune system-compromised patients, such as those getting bone marrow transplants, should avoid it, she said.

CDC officials also expect 114 million doses of seasonal flu vaccine within the coming weeks. “More than 77 million doses have gone out and more is on the way. Manufacturers have readjusted their timelines for delivery of seasonal flu vaccine due to production of 2009 H1N1 vaccine,” CDC spokesman Tom Skinner said by email.

“It will take several weeks to get the full supply going,” Schuchat added.

CDC monitoring shows that 6.1 percent of all deaths in the last week of September were due to pneumonia and influenza -- just below the threshold for an epidemic, which is 6.4 percent of deaths. More than 99 percent of confirmed flu cases are the new pandemic H1N1 virus.