French H5N1 vaccine clears test hurdle

[Mingus]

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Posted: 11 May 2006 0724 hrs

French H5N1 vaccine clears test hurdle




PARIS : A prototype French vaccine against H5N1 bird flu has been found to be safe and effective in initial tests on several hundred volunteers, according to a study published online Thursday by the British journal The Lancet.

The Sanofi Pasteur vaccine, based on a modified strain of the virus, produced protective antibodies in a phase I trial involving 300 healthy volunteers, and was well tolerated with only a few cases of severe reactions, it said.

New vaccines and medications generally undergo three test phases of increasing scope to see whether they work and have any side effects.

The trial vaccine is administered in two doses and requires a booster shot.

Thirty-one vaccines against bird flu are currently being tested on humans, 22 of them against the H5N1 strain. Eight vaccines will have undergone Phase II trials by the year's end.

The big fear is that the H5N1 virus, which at present circulates among poultry, could acquire genes that could make it highly contagious among humans.

As this has not yet happened, the present prototype vaccines are configured on the avian strain that, according to an official World Health Organisation (WHO) toll dating from May 8, has killed 115 humans through transmission from birds.

The hope is that these vaccines, if stockpiled, may provide some protection against a pandemic strain and help brake an outbreak. They could also be swiftly adjusted to cope with the pandemic strain once it is identified, it is hoped.

In a commentary also carried out by The Lancet, two US flu experts, Suryaprakash Sambhara and Gregory Poland, cautioned that no-one knows for sure whether the pre-pandemic vaccines will provide any shield.

And, they noted, the Sanofi Pasteur vaccine has a drawback because it is a two-dose formula. This limits the number of doses that can be stockpiled because of the constraints on global manufacturing capacity. - AFP /dt



Personal note: I dont know how it compare with others trials ( dose, immune response, ect ) ?

[Mingus]

Re: French H5N1 vaccine clears test hurdle

Ok, I find more about those technical details

http://abcnews.go.com/US/wireStory?id=1949387

Sanofi bird flu vaccine trial encouraging: study

May 11, 2006 — By Patricia Reaney

LONDON (Reuters) - A trial of an experimental vaccine against the H5N1 bird flu virus shows it produced a good immune response in healthy volunteers, scientists said on Thursday.

The vaccine made by a Sanofi Pasteur, a unit of the French drug company Sanofi Aventis, is based on a modified strain of the H5N1 virus.

Researchers tested various formulations of the vaccine with and without an adjuvant, an additive that can increase effectiveness. They found two 30 microgram doses with an adjuvant induced the highest antibody response after 42 days.

"The vaccine that we tested appeared to be safe and well-tolerated and we did see a good immune response, in particular in one of the doses tested," said Dr Melanie Saville, of Sanofi Pasteur who headed the trial team.

She added that the results, reported online by The Lancet medical journal, were quite encouraging but further research was needed.

In an earlier trial, a vaccine made by Sanofi produced a satisfactory immune response at two doses of 90 micrograms. The dosage is important because the less vaccine needed, the more people can be vaccinated in the event of a pandemic.

Mike Ward, an industry analyst with Nomura Code, said the 66.7 percent immune response reported in the new study was significantly better than the 50 percent seen in the earlier trial, auguring well for the product's development.

Shares in Sanofi rose 1.5 percent to 76.30 euros by 0830 GMT, outperforming a 0.3 percent advance in the European drugs sector.

DOSE-SPARING STRATEGIES

About 300 million doses of human flu vaccines are produced a year at current production capacity. Increasing production could take years and require major investments, so dose-sparing strategies to stretch supplies are important.

Scientists fear the H5N1 bird flu virus that has spread from Asia to Europe, the Middle East and Africa could mutate into a highly infectious strain that could spark a pandemic with the potential for killing millions of people Companies are racing to develop pre-pandemic H5N1 vaccines that could save lives and buy time to develop a vaccine against a pandemic strain. It could take from four to six months from the start of a pandemic before a specific vaccine will be ready.

Volunteers in the study received the two doses of the vaccine 21 days apart.

All the vaccine formulations induced an immune reaction but the biggest was in people receiving the highest dosage, 30 micrograms, with an adjuvant. The adjuvant did not improve the response to lower doses of 7.5 and 15 micrograms.

"We will be moving into Phase 2 (trials) very shortly," Saville told Reuters.

She added that the findings will be submitted to European healthcare regulators as part of its "mock up" dossier. The process is expected to reduce the time necessary for approval of a pandemic vaccine.

GlaxoSmithKline Plc has started clinical trials of two vaccines against the H5N1 virus. Chiron Corp. is also working on a vaccine.

(Additional reporting by Ben Hirschler)

Copyright 2006 Reuters News Service.


Personal note:
This is good news, using an adjuvant they are able to drive a better immune response than previously.
Using 30micrograms instead of 90mg mean 3 times more people vaccinated. This is a valuable increase.

I think annual-flu vaccine usualy require 7.5 to 15mg the lower dose they clamed has had no effects.
90mg was a ten fold higher dose, this first study was a great deception.
30mg bring us at a more workable level...