It is a race against time for global drug firms to develop a vaccine against Influenza A after the pandemic alert was raised to its top level.By declaring the first pandemic in more than 40 years, the World Health Organisation is warning governments to prepare for a long-term battle against the virus. It has advised leading drug companies to start work on a vaccine as soon as production of the seasonal shot is complete: “This is an issue that is of great importance for all countries because it is a new virus and we don’t have any immunity to it. So we will need a vaccine soon. As you may know, the seasonal vaccine is also being prepared for the northern hemisphere,” said WHO spokeswoman Fadela Chaib. While it has specified that the alert level refers to the spread not the virulence of the virus, the UN body has nevertheless warned that it could mutate into a more deadly form. While it causes mainly mild illness among patients in rich countries, it’s feared it could prove far more deadly to poor populations in the southern hemisphere already weakened by malnutrition and other disease. Since emerging in April, the A H1N1 virus has at least 145 people in some 75 countries worldwide.