Influenza may not be the great wintertime killer of the elderly as always believed. Instead, they are as likely to die from acute respiratory disease than the feared flu virus.

These findings by a Birmingham, UK, research team put a question mark over the annual ritual of having a jab as protection from the latest "killer" virus.

This groundbreaking research, based on elderly populations in England and Wales over four winters, reveals the lack of proper post mortem analysis among the elderly.

Doctors are too ready to blame an elderly person's death on the latest flu strain when it was as likely to have been caused by respiratory syncytial virus (RSV).

More significantly, it indicates that the elderly require specialist care and treatment rather than visiting their family doctor with what they think is flu.

Dr D M Fleming, head of the Birmingham Research Unit that carried out the study, points out that the findings also make impossible any useful analysis of the effectiveness of the flu vaccines.

The study explains that RSV is most likely to be spread in cold and damp conditions a typical British winter, in fact. Countries in continental Europe often experience far colder, but drier, winters than Britain, and yet report lower death rates during the season. Increasing air pollution can also exacerbate RSV.

The study team says that RSV peaks at the beginning of the year, while December tends to be the worst time for flu.

By studying all deaths in England and Wales among the over 65s, they discovered that the number of deaths caused by the influenza A and B strains varied during the four years, whereas the numbers of RSV victims each year remained constant, again making it possible to isolate the deaths due to flu.