Measles has made an unwelcome return to the United States, as dozens of children in several states have been infected with the highly contagious viral disease so far this year. There are several reasons why measles has become a major problem recently, both here and around the world, but there is one commonly speculated suspect in its resurgence that simply isn’t to blame: Covid-19.
Away early AprilAccording to the Centers for Disease Control and Prevention, 113 cases of measles have been detected in 18 states, most of them in Illinois. Two-thirds of the cases involved children and half involved children under 5 years of age. No deaths were reported, but 65 people were hospitalized for isolation or treatment of complications from the infection, including 37 children under the age of 5.
Measles was locally eradicated in the United States in 2000, meaning measles cases occurring in the country today usually originated elsewhere. But outbreaks here can and do sometimes spread. Some of the seven ongoing outbreaks in the U.S. date back to late last year, but the number of cases is already double the number reported in 2023 and is expected to be the highest in a year since 2019, when there were over 1,200 cases.
If you browse social media posts discussing these outbreaks, you’ll quickly notice people pointing to Covid-19 as the culprit. Some people argue that since Covid is known to weaken people’s immune systems, it must have created fertile ground for measles to reemerge. It’s not just measles – similar arguments have been used to explain recent increases in tuberculosis or unusual disease outbreaks, such as the cluster of severe childhood hepatitis cases that occurred in several countries in 2022. And some people have even gone so far as to nickname “Covid”AIDS in the air“– citing the known impact of untreated HIV infection on the development of other opportunistic infections.
The biggest problem with this hypothesis, at least specifically for measles, is that it is not really necessary to find a specific explanation for its reemergence. The measles virus can spread incredibly well between people who have not previously been exposed to it. So as long as there are sufficiently large groups of people in a community who are not immune to measles, there is always the possibility that wildfires will occur if the opportunity arises. Measles also remains endemic in many parts of the world, so there is no shortage of sources for new outbreaks.
“Long before Covid-19, there were measles outbreaks in unvaccinated people,” Emily Smith, an infectious disease epidemiologist at George Washington University’s Milken Institute School of Public Health, said in an email to Gizmodo.
All states require vaccination against measles and other previously common germs before children enter the public school system. And while the national childhood measles vaccination rate is still high (93.1% in the 2022-2023 school year), it has recently fallen below the 95% threshold that experts say is needed to ensure limited spread in a community (a concept known as). Herd immunity). In some regions of the U.S., vaccination rates are even lower, giving measles even more room to spread if it is ever introduced there.
As far as immunity goes, there’s nothing strange going on with these recent outbreaks. According to the CDC, 83% of cases involved people who were either unvaccinated or had unknown vaccination status, while another 12% of cases involved people who had received only one of the two vaccinations required against measles. The measles vaccine is highly effective and long-lasting (more than 99% protection with two full vaccinations), but it is not completely safe, so an occasional case can occur in vaccinated people, especially if the virus is allowed to circulate in a community long enough.
The other stumbling block here is that there’s just not much evidence that Covid is undermining our defenses against other germs on a broad scale.
“There is no evidence that Covid – or the vaccine – affects people’s immune systems,” Richard Rupp, a pediatrician and director of clinical research at the Sealy Institute for Vaccine Sciences at the University of Texas Medical Branch, told Gizmodo. “Measles has always been a concern. I think people have an image of measles as just a red patch on their face or someone as a sad sack sitting around with them. But no, it’s always been a bad disease.”
There are known life-threatening cases of acute Covid wreak havoc on the immune system, and they can increase a person’s risk of becoming infected with other germs at the same time, although this applies to any serious infection. Some people may experience persistent symptoms (even mild ones) even after the first Covid infection, a condition called long Covid. And there is evidence that at least some of the Long Covid cases may be linked to persistent, harmful changes in the immune system triggered by the infection.
But even these changes seem to be examples of this Dysregulation and overactivation of the immune system, not the kind of long-term immune deficiency that might make someone more susceptible to other infections (which is the case with HIV). At a population level, there is no data to show that rates of known opportunistic infections have exploded in the way one would expect if Covid weakens everyone’s immune system. And similar to these recent measles outbreaks, Covid is hardly needed to explain any mysterious disease outbreak that occurs. For example, the strange wave of severe hepatitis cases in children in 2022? It now appears to have been caused by a previously unknown interaction between a common virus and a rare genetic susceptibility to serious infection.
To put it bluntly, there is no good reason to consider Covid “airborne AIDS.” And it does everyone a disservice to treat it that way. Covid remains a real public health problem (at least 48,000 Americans died last year, according to preliminary CDC data), and those who have had Covid for a long time deserve more attention and research. But blaming every other health problem on the coronavirus is both inaccurate and a wasteful distraction.
For example, the pandemic has had a real impact on the global resurgence of measles by disrupting or redirecting resources existing measles vaccination programs, especially in poorer countries. Disinformation about the Covid-19 vaccine spread by the anti-vaccine movement may also have weakened public trust in other vaccines. To control measles, people everywhere must be reminded of the value of vaccination and ensure they have easy access to vaccines.