Bird flu vaccine made by new method shows promise

The first experimental bird flu vaccine made from lab-grown cells instead of chicken eggs shows promise in blocking the highly lethal virus, scientists report.

The advance is good news not just for preparations in case of a pandemic but also because it offers a way to make shots for seasonal flu much faster. That would give health officials crucial extra time to better match annual shots to the flu strains circulating.

It also would reduce dependence on the antiquated system of using millions of eggs to make flu vaccines and could cut production time roughly in half, to as little as 12 weeks, according to maker Baxter International Inc.

Results of midstage testing of the Baxter vaccine, Celvapan, showed two shots produced an immune response considered strong enough to protect 76 percent of healthy adults from both the H5N1 Vietnam strain it targets and the related Hong Kong strain; it appeared to protect 45 percent from a third, Indonesian strain.

Since the first outbreak in Hong Kong in 1997, more than 240 people in Asia, Europe and Africa have died from bird flu, which kills about two-thirds of people infected. Nearly all had close contact with poultry, but scientists worry bird flu could mutate to a form easily spread among people, who have no natural immunity. Many experts believe a pandemic will eventually occur.

The results of the company-funded study of 275 volunteers in Austria and Singapore were reported in today's New England Journal of Medicine.