How concerned should you be about mpox?
Faculty Q&A
ANN ARBOR—Mpox, a virus that causes pus-filled blisters, has been detected in several countries, including the United States, Canada, Australia and some European nations.
Aubree Gordon, associate professor of epidemiology at the University of Michigan School of Public Health, is an infectious disease epidemiologist. She is an investigator with the Centers of Excellence for Influenza Research and Response with the National Institutes of Health, director of U-M's Michigan Center for Infectious Disease Threats and currently leads several studies on SARS-CoV-2 transmission and immunity.
How concerned should we be about mpox?
We've seen a number of cases of mpox pop up in multiple countries, and that is concerning. It's definitely something that has to be monitored at this point. The good news about mpox is that it isn't as transmissible as something like SARS-CoV-2. So it should be able to be controlled. We do have existing vaccines that work against mpox, however, currently only one is licensed for that purpose in the U.S.
The emergence of something like mpox, which we've had cases pop up before, is something that's probably going to happen more and more often in the future. One of the reasons is that mpox is actually related to smallpox. If you're over a certain age, you probably have a scar from getting a smallpox vaccine, which prevented smallpox and was responsible for us being able to eradicate smallpox, but it also prevented cases of mpox.
Now we have a large population that hasn't gotten the smallpox vaccine because the virus was eradicated and because there are risks that come with smallpox vaccination. So, people are becoming susceptible or are susceptible to these other pox viruses, including mpox.
How is it transmitted?
Human-to-human transmission of mpox has been relatively uncommon. However, when it does occur, mpox is typically transmitted through close contact, either through large droplets or through direct contact with another person. Basically, you need to have contact with their saliva or pus from lesions.
One of the unique features of this particular outbreak is that it does appear that, at least in some people, it is probably being transmitted through sexual contact. There's a lot of work going on right now to figure out how it's being transmitted and what specific groups of people are at risk and who may have already been exposed to the virus.
Do you think we'll see a wide spread of this virus?
Because it doesn't transmit that easily, because we have a vaccine that works for it and because it is relatively easy to recognize cases due to the characteristic skin lesions, it should be a lot easier to control it.
That's one of the things that you look at for diseases in general, like when we think about diseases and you think about whether you can eradicate or eliminate. Eradicate is getting rid of it completely. Smallpox is an example of something that we've eradicated; there haven't been any human cases since the 1970s. Eliminate is if you get rid of it in an area or region of the world but it may still be around in other areas of the world.
Smallpox was a huge success, and there are many different reasons why we were able to eradicate it. Smallpox is incredibly transmissible but people are not typically contagious until they have symptoms. It's not like SARS-CoV-2 where you are highly infectious before you get symptoms or if you never develop symptoms. And it is very easy to identify smallpox, unlike respiratory illnesses like SARS-CoV-2. And there was a very good vaccine.
These things together, made it possible to control smallpox, eventually leading to its eradication. Since mpox also has these same features and is less transmissible between people, we should be able to control it as well.