Influenza, including H1N1, increases the incidence of heart attack by as much as 50 percent, British researchers report in the current online edition of Lancet Infectious Diseases.

While vaccination against influenza can reduce the incidence of heart attack, usually only 30 percent to 40 percent of patients receive the seasonal flu vaccine, the study authors from University College, London and the London School of Hygiene and Tropical Medicine, say.

Perhaps with pandemic fears rising, cardiologists and their patients will take heed of the new study: Scientists looked at 42 papers, published between 1932 and 2008, examining the connection between flu and heart attacks. All of the trials showed that heart attack incidence climbed during times when influenza was active: heart disease incidents soared from 35 percent to 50 percent during these periods, the study noted.

Four of eight observational studies and two small clinical trials proved that vaccination lowered MI incidence.

The authors say that flu triggers heart disease by causing inflammation in the heart and blood vessels, leading to blood clots.

China: First to Launch Vaccination Campaign

In other news, China this week became the first country to vaccinate some of its population against swine flu with a locally-produced vaccine made by Sinovac.

About 100,000 students in Beijing, due to participate in a national celebration on October 1, were first to receive the shot. (Young people under 24 are said to be in the highest risk group). The Chinese Health Ministry says it hopes it can vaccinate 65 million people, or about 5 percent of the population, by the end of this year.

Adjuvant Brouhaha

Meanwhile, in the U.S., controversy has been brewing over the possible use of adjuvants in swine vaccines--substances that increase the potency of vaccines fourfold.

Detractors, including health care personnel, say the adjuvants haven't been proven safe and that they would refuse to take any adjuvant-based vaccine approved at breakneck speed. Novartis reports that it has sold adjuvant-based vaccines to every country, except the U.S. The additives are widely used in Europe.

The WHO supports the use of adjuvants and says that given what is expected to be a worldwide shortage of the vaccine, the wealthiest countries would get it, while the poorest countries would be shortchanged without the use of adjuvants to stretch supplies.

The Bill and Melinda Gates Foundation agrees with WHO and so does FDA. "These are products that potentially can be given to millions of healthy people," said Dr. Jesse Goodman, chief scientist at the FDA. "But there's uncertainty," he conceded.

Fortunately, the use of adjuvants in swine flu vaccines may be a moot point. Studies in the last two weeks have proven that a single shot of the vaccine is enough to confer full immunity on people over the age of 10 years. Health officials had believed two shots would be necessary, prompting concerns over shortages.

Puzzling Substance

Adjuvants are still puzzling substances to many in the U.S. but scientists are now racing to study them. Currently, there is just one adjuvant-based vaccine approved in the U.S., for tetanus and hepatitis B. This vaccine uses a weak adjuvant, dubbed "Alum", for aluminum.

Gardasil, the Merck cervical cancer vaccine, also uses an aluminum adjuvant.

More powerful adjuvants are in the pipeline. For example, An FDA advisory panel recently recommended approval of Cervarix, a vaccine against the virus that causes cervical cancer. The vaccine, made by GlaxoSmithKline, uses an adjuvant that's a bacterial lipid.

Also in the news, CNN medical correspondent Sanjay Gupta, M.D. acknowledged that he and a camera operator came down with the H1N1 flu during a recent assignment in Afghanistan. They have recovered according to CNN.