US HHS has not learned from H1N1 mistakes-senators

* Senators say HHS caused confusion over vaccine

* Hearing planned for Tuesday

* Vaccine adviser says system is working

WASHINGTON, Nov 16 (Reuters) - U.S. officials raised expectations too high in handling the swine flu vaccination campaign and failed to allocate scarce vaccine effectively, two influential U.S. senators said on Monday.

Connecticut independent Senator Joseph Lieberman and Maine Republican Susan Collins praised the Health and Human Services Department for working quickly, but said the agency had sent a mixed message to the public.

“The glaring discrepancy between the demand for and supply of H1N1 vaccine in our country has resulted in pregnant women standing in line for hours, only to find no vaccine at the end,” they wrote to HHS Secretary Kathleen Sebelius.

The U.S. government has been struggling to provide vaccines against the pandemic H1N1 virus, which has infected an estimated 22 million Americans and killed at least 3,900.

President Barack Obama’s administration built on years of preparation for a pandemic, but now risks losing the confidence of a public already suspicious of public health campaigns.

Companies have run into repeated obstacles in making the vaccine, which is manufactured using 50-year-old technology based on eggs.

“This shortage of vaccine has left many parents of children in high-risk groups scrambling, often in frustration, to find the vaccine the government has told them that they need,” Collins and Lieberman wrote.

“However, your response does not acknowledge any missteps by the government, a sure sign that lessons have not been learned to ensure that this situation does not happen again.”

Collins and Lieberman will hold a hearing on Tuesday of the Senate’s Homeland Security and Governmental Affairs Committee to discuss the matter.

They expressed concern about the U.S. Centers for Disease Control and Prevention’s decision to designate 159 million people as having priority for vaccine, and HHS projections about how much vaccine would be available and when.

The CDC’s advisers on vaccination policy voted in July to create five broad priority groups -- pregnant women, healthcare workers, people with asthma, diabetes or other conditions that put them at high risk of flu complications, caregivers of infants too young to be vaccinated, and children.

“There was a lot of thinking that went into this,” said Dr William Schaffner of Vanderbilt University in Tennessee, a member of the advisory committee, in a telephone interview.

“If they are turned away or sent away, they frequently don’t come back. So you wind up ... with unused vaccine.”

Schaffner said it was also key to let state and local officials decide who, precisely, to vaccinate. Some hospitals, for instance, did not want to use the first available vaccine, a nasal spray made by AstraZeneca AZN.N unit MedImmune.

But Collins and Lieberman said the message was too confusing.

“This approach raises doubts about our capacity to respond effectively to the ongoing epidemic, but also to prepare effectively for what could be even more serious epidemics in the future,” they wrote.

Collins and Lieberman have also more than once criticized HHS for its initial rosy predictions that there would be vaccine for “everybody who wants it” -- with projections of 160 million vaccines by the first week of December.

On Friday, just under 42 million doses were available. (Editing by Alan Elsner)