Plenty of viruses are having their strongest season for years. But experts have urged calm about HMPV, which is not a new disease — even if you've never heard about it.

Young children, older adults and those with weakened immune systems are at a higher risk of developing severe illness due to HMPV.

The WHO has downplayed concerns over a rise in HMPV cases, saying outbreaks are normal during winter in the Northern Hemisphere.

An expert has warned that the new virus currently spreading in China could reach "other parts of the world." The human metapneumovirus (HMPV), which has seen a recent surge in cases across China, has prompted the country’s Centers for Disease Control to call for additional measures to curb its spread.

Human metapneumovirus (HMPV) spreads rapidly in China, causing respiratory illnesses, with rising cases also reported in India.