The UK Medicines and Healthcare products Regulatory Agency yesterday reinstated the licence for Chiron Corporation’s Liverpool manufacturing plant, where the firm makes its Fluvirin flu vaccine. The news sent the biotechnology company’s share price up by as much as 16% during trading on the Nasdaq Stock Exchange yesterday.

The MHRA suspended the plant’s licence back in October last year after finding manufacturing deficiencies [[06/10/04b]]. The news triggered a major public health catastrophe for the USA, which was left with just half its planned 100 million flu vaccine doses for the 2004/5 season. Only two other flu vaccines are approved in the USA – one from Sanofi-Aventis and the second from MedImmune – and, although the USA did manage to secure additional supplies from these suppliers [[20/10/04d]], [[25/10/04e]], it was still left with a significant 39 million-dose shortfall.

In a statement, the UK regulator said that its inspectors had concluded that "satisfactory progress has been made in the manufacturing areas which had previously caused concern… the company… is now free to recommence full manufacturing of the vaccine.” Chiron says it will be providing the MHRA with regular weekly updates to ensure that progress on various projects proceeds satisfactorily.

The US Food and Drug Administration said that the development was an “extremely important milestone” for Chiron, but acknowledged that “work remains.” It is planning to conduct a full site inspection “when all critical stages of manufacturing are in full swing, and needed corrective actions can be fully evaluated.”

Howard Pein, Chiron’s chief executive, heralded the news as a “significant accomplishment.” He added: “We remain focused on continuing to remediate and improve so Chiron can successfully deliver on the results required to supply influenza vaccine for the 2005-2006 season.”