Finally, human metapneumovirus was taken seriously

Like many other respiratory viruses, Williams says HPV tends to affect those with chronic lung disease or existing conditions like asthma and cancer. But despite this, it has been found that many doctors do not realize that it is a threat, largely because until relatively recently, no one was testing it outside of academic studies.

“There’s no doubt that even within the medical community, many doctors don’t realize how common HPV is,” he says. “As clinical testing has become more available, people have told me to their surprise, ‘I had a patient in my ICU with metapneumovirus last week. It’s real, and I never believed it before. Until people see it for themselves, I think they don’t fully believe the burden.

It’s possible that there have been significant increases in hMPV cases in the past, but we either weren’t aware of them or mistook them for influenza, Vermund says. One consequence of Covid, he explains, was the recognition of the need for greater surveillance of circulating respiratory viruses, which meant that epidemiologists discovered HPV case numbers for the first time.

“The Chinese have become very advanced in molecular diagnosis of respiratory viruses, and they do a lot of public health surveillance, more so than many other countries,” he says. “I think what we might see is that they do a particularly good job at this, so finding the virus following pneumonia is more common than we used to realize.”

Williams believes the current surge of interest in hMPV could have positive public health consequences. Right now, he says hMPV can only be detected as part of what’s called a multiplex panel, a diagnostic that checks for up to 25 different respiratory viruses, at a cost of about $200 per patient. While this is a worthwhile investment for emergency room doctors who decide to admit or send a sick child home, these costs are often prohibitive for lay doctors.

“There are cheap tests for influenza, Covid, and respiratory syncytial virus that doctors can use anywhere,” he says. “But there isn’t really any cheap test for hMPV, just this complex diagnostic panel that evaluates multiple viruses that is difficult for the average clinic to obtain.”

There are hopes that a low-cost test for hMPV could be on the way. According to Vermund, the Ragon Institute in Massachusetts is working on ways to try to get the price of testing for respiratory viruses down to less than $6 per patient, with the eventual goal of getting the cost down to less than $1.

Likewise, another consequence of increased awareness about hMPV is that it provides stronger incentives to accelerate vaccine access. To date, there is no licensed vaccine available for the virus, but a series of vaccine candidates have been introduced Clinical trials are in early phase In the past two years.

Last summer, scientists at Oxford University Launched a clinical trial Of a joint RSV and hMPV vaccine in partnership with Moderna, Andrew Pollard, a professor of infection and immunity who runs the Oxford Vaccine Group, says adding hMPV to existing vaccines would be the most practical way to introduce additional immunization.

“If you can put them in the same vaccine, like RSV and hMPV, without the need for additional needles, you actually cover more respiratory hospitalizations,” Pollard says. “But before we can do that, we need to know how often you need to be vaccinated against HPV. If you can provide immunity by vaccination every few years, you can combine it with RSV.”

Overall, Vermund describes the sudden interest in hMPV as an important development. Although the virus will not lead to the next pandemic, it is still infecting a large number of people, creating a major strain on public health systems, as well as being a long-standing cause of death among vulnerable groups.

“Although pneumonia is not one of the deadliest viruses, it is incredibly common,” he says. “It’s caused a fair amount of colds over the years, which is an incredible economic burden, and every now and then it kills someone.”