Vaccine producers' resources meet pandemic demand.

Concerns over growing cases of avian flu and the possibility of a flu pandemic have led to more people than usual seeking vaccination against seasonal flu, even though this would not protect against a pandemic strain.

News of how the UK government was caught short in the wake of an impending pandemic is surprising, considering the media hype fuelling public concerns about the bird flu pandemic threat.

The UK's Department of Health (DoH) currently meets vaccine manufacturers each year to discuss requirements based on previous demand and other factors, which need to be taken into account.

The understanding was based on 11 million people being at risk, but was recently revised to 13.2 million.

The Department of Health said the 14 million vaccine doses ordered by GPs from manufacturers and held in a contingency pot by government had all been used. The department has ordered 200,000 more doses, but those will not be available until 2006.

Influenza vaccines need to be changed, generally each year, to cope with mutations and this need to change vaccine formulations results in delays when flu breaks out.

Human flu is caused by two influenza strains, A and B. The killer bird flu virus H5N1 is a derivative of the A strain. The pandemic vaccine is being developed to tackle the A strain while the universal vaccine should act against A and B.

Vaccine manufacturers have certainly learnt the lessons of last year, when fingers were pointed at producers such as Roche and GlaxoSmithKline. This year has seen considerable time and effort invested into stepping up production to meet demand. Roche makes Tamiflu and GSK​ an inhalable drug called Relenza.

Samantha Christey, manager, GSK Biologicals World Wide, told In-PharmaTechnologist.com:​ "Recently GSK has invested $2 billion to expand the company's flu vaccine manufacturing capacity and to increase the production of its antiviral Relenza (zanamivir for inhalation). Both could help meet public health needs in the case of pandemic."​

"The company expects to increase its North American manufacturing capacity with the proposed acquisition of ID Biomedical, a Canadian vaccine manufacturer,"​ she added.

Special preparations to cope with the expected demand include an investment of € 94.3 million to double production capacity for its Influsplit/Fluarix flu vaccine at its Sachsisiches SerumWerk (SSSW) plant in Dresden, Germany.

Christey added: "GSK will build a second plant at the site and increase its annual production capacity from 35 million influenza vaccine doses per year currently, to 60 million doses annually before the end of this decade."​

Meanwhile Roche​'s response to the flu outbreak has resulted in production reaching full capacity. Almost all governments have ordered it, and thus demand may not be satisfied.

Roche had commented that it might allow other companies or governments to make it under licence.

"More than 200 requests from third parties have been received to date and Roche production experts have already been in initial talks with 8 companies, amongst them large generic manufacturers and major pharmaceutical companies, as well as with a number of governments, including Taiwan and Vietnam,"​ the company said.

"The goal is to be in a position to select potential partners for more detailed discussions by the end of November."​

The company has also said it hopes to be able to step up its own annual production of Tamiflu to 300 million treatments, 10 capsules per treatment, by 2007. It has 12 outside suppliers that can perform parts of the process.

Other vaccine manufacturers such as Chiron​ are pursuing alternative ways, namely to make vaccines that might help prevent people from getting bird flu.

In October this year, they announced that it has initiated a Phase I/II study of an investigational cell culture-derived influenza vaccine in the United States.

Production of influenza vaccine using cell-culture technology may offer significant advantages over traditional manufacturing methods by eliminating the dependence on chicken eggs for production.

The removal of egg supply lead times would enable flexible and faster start-up of vaccine production in the event of an annual vaccine supply shortfall or an avian influenza pandemic.

However one major disadvantage is of course, cost. Changing to cell-based vaccine manufacturing could cost the company billions of dollars.

The other major vaccine manufacturer, Sanofi-Pasteur has entered a series of contracts designed to speed the production process for new cell culture influenza vaccines.

Only this month, Sanofi Pasteur​, had entered into an agreement with the French Ministry of Health to produce pre-pandemic vaccine in 2005 against the H5N1 avian strain.

The deal would mean a stockpile of 1,400,000 doses of vaccine would be created. The agreement also commits the company to being ready to provide enough vaccine for 28 million people in the event of a pandemic being declared, once the actual virus strain responsible has been identified.

Sanofi Pasteur is the only vaccine manufacturer to participate in FLUPAN, an EU-funded collaboration that is intended to improve the level of pandemic preparedness in the EU.

Under the terms of the agreement, Sanofi Pasteur is to produce a vaccine to combat another strain with pandemic potential (H7N1) that will be used in a FLUPAN clinical study.