Single Swine Flu Vaccine Dose May Be Enough

The answer may be at hand to a crucial question about vaccination for the advancing swine flu — one shot or two? Chinese officials approved a vaccine Thursday that they say prevents the new flu in a single dose.

Photo: Single Swine Flu Vaccine Dose May Be Enough

If they're right, it would be good news. Many health researchers fear it will take two shots to protect people, vastly complicating efforts to stem the spread of the illness.

The World Health Organization says it is encouraged after reviewing the test details from the vaccine by Beijing-based drug maker Sinovac Biotech Ltd. — one of several being developed in China. However, experts said more results are needed from other vaccine makers to determine if one dose would be potent enough, The Associated Press reports.

The outbreak of the H1N1 strain of flu, declared a pandemic on June 11, has spread around the world and could eventually affect 2 billion people, according to World Health Organization estimates.

Many experts expected that two doses per person would be needed by health authorities preparing for a possible second wave of infections at the start of the northern hemisphere winter.

Vaccination is expected to get under way in some countries this month with many others starting in October.

Novartis said its H1N1 vaccine had a strong immune response after just one dose in a pilot trial, and Chinese health authorities gave a green light to Sinovac, which says its vaccine also needs only one shot to be effective, Reuters informs.

“The pilot trial results are encouraging,’’ said Andrin Oswald, chief executive officer of Novartis Vaccines and Diagnostics. “While two doses seem to provide better protection, one dose of our adjuvanted Celtura vaccine may be sufficient to protect adults against the swine flu. This is important information for public health authorities who prepare for vaccination in the coming months with limited vaccine supply.’’

The vaccine, which will be called Celtura, was tested in patients between the ages of 18 and 50, Novartis said. Additional clinical trials that will include more than 6,000 adults and children are already under way, Bloomberg reports.