Vaccines to combat a virus that can lead to fatal lung infections are urgently needed to help prevent child deaths worldwide, research suggests.

Experts report that more than 115,000 children under five are dying each year from complications associated with the infection, called respiratory syncytial virus (RSV).

Almost half of those who die in hospital are younger than six months old and more than 99 per cent of deaths occur in developing countries, the study estimates. Half of the RSV deaths in these countries occur outwith hospital.

Five countries – India, China, Nigeria, Pakistan and Indonesia – account for half of the estimated cases of RSV worldwide.

Researchers say more data are needed from Africa and South Asia, where the number of RSV infections may be even higher. Their findings highlight the pressing need for affordable treatments and vaccines as a priority.

The team led by the University of Edinburgh analysed data from 329 studies of RSV infections worldwide.

Their estimates indicate there are more than 33 million cases of RSV infection in children under five each year worldwide.

The study was conducted by the RSV Global Epidemiology Network, which includes researchers from 78 institutions and 35 countries worldwide.

It was published in The Lancet journal.