Big drugmakers start trials of swine flu vaccines

By Ben Hirschler and Caroline Jacobs

LONDON/PARIS, Aug 4

Novartis has started human testing of H1N1 swine flu vaccine candidates while Sanofi-Aventis, the world leader in flu shots, will commence within days, company officials said on Tuesday.

The launch of clinical trials is a key part of a widening programme of work being undertaken by big pharmaceutical companies as they prepare for mass vaccination from next month.

GlaxoSmithKline, the other "big three" flu vaccine supplier, said it would initiate clinical studies later this month.

H1N1 swine flu, which first surfaced in Mexico in April and was declared a pandemic by the World Health Organisation (WHO) in June, has infected millions and killed an unknown number.

The WHO stopped counting at 800 confirmed deaths, since not every patient can possibly be tested.

Healthcare officials are relying on a vaccine to contain the spread of disease, providing a potential sales windfall for those companies that are able to deliver quickly and in large volume.

Australia's CSL has so far been the fastest commercial operator, after starting its first clinical trials in Australia two weeks ago. Now others are catching up.

"We started a little over a week ago," Novartis spokesman Eric Althoff said by telephone from Basel.

Benoit Rungeard, product communications director for Sanofi Pasteur, the vaccines division of the French drugmaker, told Reuters his company would start "in the coming days or next week".

Althoff said Swiss-based Novartis was conducting its clinical trials in a number of countries, including the United States, Britain and Germany, and was testing both single and booster, or repeat, doses of vaccines.

Novartis, in common with other manufacturers, will also compare vaccines with and without adjuvants -- ingredients that boost the immune system response.

AstraZeneca, whose MedImmune unit makes smaller amounts of a flu vaccine that is sprayed into the nose rather than injected, said it would start clinical trials in the United States around Aug. 17.

As well as racing against the clock, vaccine companies are also working flat out to maximise their production capacity.

Initially, all the manufacturers except MedImmune -- which uses a different process -- struggled with low yields when making swine flu vaccine, with most companies only getting about 30 percent of the usual yield of seasonal flu strains.

But that is starting to improve.

"We are higher than that (30 percent)," Sanofi's Rungeard said.

"During the production campaign the yield increases because we learn how to better use it -- at the beginning it is not same as at the end," he added. Regulators in Europe and the United States plan to fast-track approval of swine flu vaccines to ensure they are available for the start of the northern hemisphere winter.

At the moment swine flu is rated only a "moderate" pandemic by WHO standards but it could worsen as temperatures cool, making conditions better for the virus.

(Reuters)