Researchers who analysed over 40 years of data have  concluded the current  crop of vaccines offers only inadequate protection against seasonal flu outbreaks and serious pandemics alike. Evidence for their effectiveness in older individuals was lacking, according the researchers who pooled the results of 31 studies published over four decades.

The most commonly used seasonal influenza vaccine “trivalent inactivated vaccine (TIV)” was shown to be only 59% effective in healthy adults.

Dr Michael Osterholm, from the University of Minnesota in the US, one of the lead authors of the study published in the journal The Lancet Infectious Diseases, said: “The ongoing health burden caused by seasonal influenza and the potential global effect of a severe pandemic suggests an urgent need for a new generation of more highly effective and cross-protective vaccines that can be manufactured rapidly.

The research has shown that pandemic swine flu vaccine was around 69 percent effective in people under the age of 65. “This amount of protection is not adequate for a pandemic setting. The difference between 69% effectiveness and 90% effectiveness (or greater) will have a major public health effect in any pandemic that causes serious morbidity (illness) or increased mortality.”