Human metapneumovirus (hMPV) has probably been infecting people for centuries
BY ROGER HARRIS/SCIENCE PHOTOGRAPHY
Alarmist headlines warning that China is in the grip of a mysterious new virus have dominated the past few days. But the virus reported to be responsible for the rise in respiratory infections there, called human metapneumovirus, or hMPV, is really neither mysterious nor new, and Chinese authorities have dismissed its claims. the health the system is flooded.
What is human metapneumovirus?
It is one of the different ones the viruses they are called cold viruses because they infect the cells of our respiratory tract and cause “common cold” symptoms such as a sore throat, runny nose, cough and sneezing, which can last for several days. You’ve most likely had HMPV infection: antibody studies show that by age 5, almost everyone is infected. As with the flu, people can be re-infected throughout their lives as immunity wears off and new variants develop.
How dangerous is hMPV?
In most people it causes only mild symptoms, but like other cold viruses, it can occasionally be more severe and even fatal. Serious infections usually occur in people who are vulnerable for some reason, including very young children, the elderly, and those with conditions such as a compromised immune system or asthma.
Globally, the virus is estimated to have killed at least one 11,000 children In 2018, under 5 years. For comparison, another cold virus called respiratory syncytial virus or RSV is estimated to kill. 60,000 children every year worldwide.
How long has hMPV been in people?
It has probably been spreading in humans for centuries. The virus was first discovered in 2001 in samples taken from children in the Netherlands with respiratory infections. Since then, it has been found in samples stored since 1976, and antibodies against the virus have been found. blood samples From the 1950s onwards.
Where did it come from?
Narrow viruses known as avian metapneumoviruses circulate in birds and the human metapneumovirus is thought to have evolved from one of them. However, it is believed to have occurred about 200 years ago, so the situation with hMPV is very different from that of the covid-19 virus, which only jumped to humans in late 2019. Although hMPV is currently a human virus, it can infect. other animals, including chimpanzees and gorillas.
What kind of virus is it?
It belongs to a group called paramyxoviruses, consisting of a single strand of genetic material. RNA embedded in a protein layer. Other paramyxoviruses include measles and Nipah. hMPV’s genome is about 13,000 “letters” long and encodes only nine proteins, making it a relatively small and streamlined genome, like many other respiratory viruses.
Is there a treatment or vaccine for hMPV?
There is no specific treatment or approved vaccine for hMPV infections. However, several potential vaccines are under development. For example, in 2024 a team from the University of Oxford began testing one mRNA vaccine It is designed to protect children against hMPV and RSV.
Why are there so many cases in China?
It is normal for waves of cold and flu infections to occur during the winter, and some years these waves are greater than others for reasons that are not well understood. More infections generally mean more severe cases and therefore more hospitalizations. “There is nothing that indicates anything abnormal. So far, they seem to be doing what normal seasonal endemic villains do.” writes Ian Mackay At the University of Queensland in Australia, he noted that there was a remarkable one similar fear in 2023
How do we know we’re not seeing the start of another pandemic?
The COVID-19 the virus was a new virus, meaning people had no immunity. This allowed it to spread widely and make it more likely to cause serious infections. In contrast, the hMPV variant circulating in China differs only from other hMPVs few mutationsthat is, most people – apart from small children – already have some immunity.
It has been claimed that this new variant can cause serious infections, but even if it is true, this does not mean that it will cause another pandemic. Indeed, Chinese Foreign Ministry spokesman Mao Ning he said on January 3 respiratory infections “compared to the previous year are not more serious and appear to spread on a smaller scale”.
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