MedImmune has presented some good news to its prospective new owners AstraZeneca as a panel of experts in the USA has recommended expanding use of its FluMist influenza vaccine to very young children.

The US Food and Drug Administration's Vaccines and Related Biological Products Advisory Committee has voted in favour of expanding FluMist to include children under five years of age who have no known respiratory problems and in addition, the panel was satisfied with the risk-benefit profile of the vaccine in children from 12 to 59 months of age without a history of wheeze. It also voted in favour of allowing use of the nasal spray for youngsters aged 24 to 59 months of age regardless of whether they have wheezing problems.

FluMist is currently approved for healthy children and adolescents of five to 17 years of age and healthy adults aged 18 to 49. The FDA is expected to respond to the company's supplemental Biologics Licensing Application requesting the expanded indication by May 28, and the agency almost always follows the advice of its expert panels.

The advisory committee did, however, express some concerns about the risk of wheezing, a point MedImmune has acknowledged. Data has shown an increase in hospitalisations for children aged six to 11 months, so the company says it is only seeking expanded approval of FluMist for children aged 12 months or above, and it added that further studies will be undertaken to evaluate kids who have a history of wheezing and asthma.

Wider approval for FluMist would give MedImmune a major boost as the vaccine has not had a wholly successful time on the market since it was first approved, though this was due partly to the fact that it was difficult to distribute in its original frozen form. The newer spray can be merely refrigerated.

MedImmune is planning to produce seven million doses for the upcoming 2007-2008 flu season, as much as it has distributed in the whole of the last four years. The spray, which had sales of $36.4 million last year, will compete with injectable flu vaccines from GlaxoSmithKline, Sanofi-Aventis and Novartis' Chiron unit.

– Meantime, AstraZeneca says that it is confident that its $15.6 billion acquisition of MedImmune will go ahead, despite the class-action lawsuit filed yesterday by an aggrieved shareholder of the US firm who believes the latter’s management has not acted in good faith. MedImmune has stated that it does not believe the suit has any merit.