The British government says it plans to double its stockpile of antiviral drugs such as Tamiflu to cope with the possibility of a flu pandemic.
Roche the Swiss drug manufacturer which makes Tamiflu is apparently geared up to meet the increased demand.
The Health Department has already ordered enough of the drug to protect half the population once a strain has been identified.
Many health experts believe a global influenza pandemic is almost inevitable and the most likely candidate at present appears to be the H5N1 avian flu virus currently attacking birds across Asia, Africa and parts of Europe.
Should a pandemic strike as much as 50% of the population could be affected and experts say up to 2.5% of those infected could die.
The Health Minister Alan Johnson says a flu pandemic is "one of the most severe risks" that Britain faces.
The Department of Health has awarded contracts to GlaxoSmithKline and U.S. group Baxter International worth 155.4 million pounds over four years to supply a pandemic flu vaccine as soon as the strain is identified and made available by the World Health Organisation.
The British government is also buying 14.7 million courses of antibiotics, 34 million respirators and 350 million face masks.
Meanwhile in the United States the Food and Drug Administration (FDA) are saying that both Tamiflu and Relenza, another flu drug, should carry warnings about possible psychiatric side-effects.
The warning follows reports from Japan that children in particular have experienced delirium, psychosis and hallucinations, after taking the drugs; apart from these side effects there have also been reports of deaths.
Three Japanese adults committed suicide while on Tamiflu and five children died, also since 1999, when Relenza was first approved, there have been 115 reports of psychiatric related events, of which 74 were children.
Tamiflu (oseltamivir) is a pill, while Relenza (zanamivir) is inhaled.
The safety of the treatments are about to be reviewed by a panel of experts but the FDA says the warning should be directed at patients of all ages and not just children and the products will continue to be monitored.
The threat of a pandemic in recent years has prompted many governments throughout the world to amass stocks of Tamiflu as a precaution.
Japanese Health authorities already warn against the use of Tamiflu and Relenza in patients aged 10-19.
Roche says there is no definite proof of a causal relationship between Tamiflu and abnormal behavior and says clinical and non-clinical studies are currently being conducted.
The Australian inventor of the original flu jab created more than 40 years ago, Dr. Graeme Laver has voiced fears over the vaccine's effectiveness.
Dr. Laver has warned it will do little to prevent a flu epidemic in Britain this winter, and says he believes it should not be relied upon to protect from a potentially severe flu epidemic.
The Australian scientist claims that people's lives could be saved if drugs such as Tamiflu and Relenza were used instead, once the disease has already struck.
Dr. Laver suggests both prescription-only drugs should be sold over the counter so that they were more readily available to flu sufferers.
Laver says the seasonal flu was severe in Australia this year and the number of flu victims tripled compared to last year.
His comments lend support to a recent study by the Health Protection Agency (HPA) which found the vaccine had no "protective effect" on lowering numbers of elderly people admitted to hospital with respiratory infections.