Flu is widespread in Massachusetts and 47 other states, but deliveries of vaccine against the swine flu virus have lagged behind both illnesses and supply projections. Manufacturers are struggling to produce both the new vaccine and seasonal flu vaccine at the same time.

A telephone survey conducted last weekend by the Harvard School of Public Health found that four out of 10 American parents and one out of five high-priority adults were looking for swine flu, or H1N1, vaccine. Slightly fewer than one out of five adults not in a high-risk category were also searching for vaccine.

High risk groups include pregnant women, adults caring for a baby less than six months old, health care workers and emergency personnel, and adults age 25 to 64 who have medical problems such as asthma or heart disease.

Two-thirds of parents looking for vaccine were unable to find it for their children. The same was true for high-priority adults. Seven out of 10 other adults seeking vaccine were also unable to get inoculated.

"These findings suggest that the nationwide H1N1 vaccine shortage is presenting a real challenge for those who have tried to get the vaccine," Robert J. Blendon, professor of health policy and political analysis at Harvard, said in a statement released with the poll.

Almost all people polled said they will keep looking for vaccine, for themselves or their children, the survey said.

The survey was conducted by calling 1,073 adults, on both landlines and cell phones, from October 30 through November 1. The margin of error is plus or minus 3.8 percentage points. It is the fifth survey done by the Harvard researchers since swine flu emerged in the spring.

This article was originally posted on White Coat Notes.