July 31 (Bloomberg) -- A U.S. plan to rely on swine flu vaccines without ingredients to stretch the supply would reduce the number of available shots just when other countries need them most, the British journal Lancet said in an editorial.

The ingredients, called adjuvants, have never been approved for flu vaccines in the U.S. and are controversial because some studies show they cause immune disorders in mice. The World Health Organization recommended on July 7 that adjuvants be used to boost global amounts of vaccine, and the Lancet criticized the U.S. for plans to rely exclusively on standard formulations.

The U.S. Health and Human Services Department declared a public health emergency over swine flu in April, giving the Food and Drug Administration the power to allow the use of unapproved medical products including adjuvants. The health department agreed to purchase more than $415 million of the vaccine additives, while saying it may not use them if enough shots are available for U.S. residents.

“The USA must support the use of dose-sparing strategies to avoid depletion of an already short vaccine supply,” said the authors of the Lancet editorial. “All countries will require the vaccine, but current manufacturing capacity will not be able to meet this demand.”

Spreading Quickly

A pandemic of swine flu, also known as H1N1, has infected more than 1 million people in the U.S. and swept across the globe. Drugmakers are racing to get a vaccine ready for October, when lower temperatures may bolster a wave of outbreaks across the northern hemisphere.

The Lancet, a journal of medical research founded in 1828, was the second-most cited general medical publication in the world in 2007, according to the Institute of Scientific Information’s Journal Citation Reports. The institute evaluates the impact of academic publications based on how many times their articles are cited elsewhere.

Adjuvants are mixes of oil and water that trigger a stronger response in the body to antigen, the substance that induces immunity. The additives, whose effectiveness vary by flu strain, may boost the strength of the antigen as much as 10- fold, as was the case with a bird flu vaccine approved in Europe, said John Treanor, a professor of medicine, microbiology and immunology at the University of Rochester, in an interview.

MF59, an oil-and-water adjuvant made by Novartis AG and approved in Europe, has been safely given to more than 40 million people, mostly adults, to prevent seasonal flu, according to the company.

Adjuvant Tests

The U.S. plans human tests to determine safety and effectiveness of flu adjuvants and will “review all clinical data to inform our decision on their potential use,” said Bill Hall, a spokesman for the Health and Human Services Department, in an e-mail.

“We have provided significant support to the World Health Organization’s vaccine programs, and we will continue to work to support our international partners and developing nations around the world,” Hall said.

The U.S. Centers for Disease Control and Prevention agreed to pay London-based GlaxoSmithKline Plc and Novartis, based in Basel, Switzerland, more than $415 million for adjuvants that could be added to the swine flu vaccines, according to a July 13 statement.

The additives may not be necessary if enough shots can be produced without them, HHS officials said. Authorities at the CDC said July 29 that 40 million shots of unadjuvanted vaccine may be available to the U.S. in September, earlier than previously reported, with 80 million more doses ready in October.

Egg Yields

Drugmakers have found it difficult to cultivate the quantities of virus necessary for an H1N1 vaccine. The strain yields 50 percent to 75 percent less antigen compared with a typical seasonal flu strain, according to the WHO. The virus didn’t initially grow well in eggs, the principal medium used by the industry, vaccine makers said.

Scientists have significantly improved yields in eggs recently, which should ease pressure on manufacturers, said Robin Robinson, chief of the Biomedical Advanced Research Development Authority, the U.S. agency in charge of buying the vaccine. A decision on adjuvant use hasn’t been made, he said July 29 during a meeting at the Atlanta-based CDC.

“Already our development efforts have resulted in an improvement of yields,” Donna Cary, a spokeswoman for Paris- based Sanofi-Aventis SA, said yesterday in telephone interview. “Certainly every improvement in yield potentially means more vaccine sooner.”

Yields still appear to be lower than typically seen with seasonal flu, she said.

Glaxo’s adjuvant has proven safe and effective in clinical trials with 39,000 people, said Lisa Behrens, a spokeswoman for the company, in an e-mail. Glaxo will conduct more studies and continue to monitor safety after the vaccines are in use, she said.

To contact the reporter on this story: Tom Randall in New York at Trandall6@bloomberg.net

Last Updated: July 30, 2009 19:52 EDT