Unlike COVID-19, human metapneumovirus has been around for decades, and we understand how it spreads and how to treat it.

While cases are climbing in China, the situation is very different from what it was when Covid-19 emerged five years ago, medical experts say. HMPV is common and decades old.

HMPV has many of the same symptoms of mild, common winter woes like cold and flu, but it can lead to much more severe complications, particularly in vulnerable groups like infants, the elderly and people with weakened immune systems.