Fauci Discusses Public Misperceptions About Viruses
Emerging from the height of cold and flu season, it may seem as though there are dozens of new, increasingly stubborn viruses out there. This, in fact, is not the case.
“There is not this whole hoard of unnamed viruses that we do not know about,” said NIAID director Dr. Anthony Fauci, in a recent conversation with the NIH Record. “Everything that really is out there, we know about.”
Viruses tend not to become more severe, though certain viruses can vary in their virulence. The influenza strain H3N2 a year ago, for example, was quite virulent and more likely to cause complications than the predominant flu strain (H1N1) this past winter.
“I guess that is one of the interesting aspects, but one of the confounding aspects of colds, particularly in the winter,” said Fauci. “When people get a sore throat, they get an upper respiratory infection (URI)— they sneeze, they cough—sometimes they get sinusitis; sometimes they go on to get a complication like pneumonia. Some of the viruses that cause URIs are very mild inherently, with very little chance of there being severity.”
Rhinoviruses, which are responsible for at least one-third of adult colds, are an example. They generally cause a mild URI. Other URIs can be mild or more serious when caused by such viruses as influenza.
“Some URIs are always mild and rarely get serious,” said Fauci. “Some are mild and not infrequently get serious. And some can be very serious.”
If symptoms do not go away, that is the time to seek help. Then it is possible that a secondary, bacterial infection has developed such as sinusitis or pneumonia, which in that case would require antibiotics.
Fauci also discussed two viruses that have made headlines in recent months.
In November 2018, a 19-year-old University of Maryland student died after contracting adenovirus, one of dozens of cases of the highly contagious virus reported on the campus around that time.
“Adenoviruses are very common,” said Fauci. “They tend to occur in outbreaks in close quarters. It is a big problem in boot camp in the military and that is why the military vaccinates their recruits against a couple of the adenoviruses.”
Adenovirus is generally not deadly, said Fauci. The student who died had a compromised immune system from an underlying illness.
“She was not a normal host,” he said. “Very, very rarely do you get an otherwise normal, healthy person get so sick that [he or she dies] from an adenovirus.”
Another viral condition making news in recent months is acute flaccid myelitis (AFM), which affects the nervous system and, in serious cases, can cause paralysis.
Proving what triggers AFM has been tough because the virus is difficult to isolate, said Fauci, but circumstantial evidence points to a specific enterovirus as the cause.
“It is one of those hit-and-run viruses,” said Fauci. “You get infected, then you cannot isolate it, but you get a post-infection syndrome—in this case paralysis.”
AFM is rare, contracted by less than one in a million people. An entire family might get infected with the same enterovirus but only one member might get AFM due to environmental, genetic or other predispositions that led to the otherwise rare complication.
“Remember, enteroviruses are all over the place,” said Fauci. “They are very common viruses. Virtually everyone, at one time in their lives, was infected by an enterovirus, including you and me. Only rarely do enteroviruses cause acute flaccid myelitis. The complication is rare, but the virus is not rare.”
Most incidents of AFM in recent years have been reported among children. That is because most adults already contracted an enterovirus when they were younger, explained Fauci, and built immunity from previous exposure.
“You escaped getting flaccid paralysis when you were a child and now you are an adult,” he said. “Meanwhile, the children are getting infected for the first time and you do not know if their predisposition—genetically or otherwise—is going to allow them to get AFM.”
Enteroviruses are generally treated symptomatically and there is no cure for AFM.
“If someone gets the rare complication of AFM,” said Fauci, “then very aggressive physical therapy has been shown to be beneficial in preventing the advancement of the physical disability.”
There is also no vaccine for AFM because “you would not know whom to vaccinate,” said Fauci. There are many kinds of enteroviruses, most of which cause mild infections.
The topic of vaccinations has also hit the news in recent months, as outbreaks of measles have been reported in Washington state, New York and elsewhere.
“First of all, it is important to establish that these measles outbreaks are all associated with lack of vaccinating children,” said Fauci. “So the anti-vax movement is at the root cause of the outbreaks that you have read about.”
Misinformation about vaccines lingers on the internet and gets propagated on social media. Addressing the anti-vaccination community can be complicated though.
“Some people are inveterate anti-vax’ers and no matter what you say or do, they are not going to change their minds,” said Fauci. “But there are some people who are preventing their children from getting vaccinated and can be convinced otherwise. The way you approach them is not to criticize or denigrate them, but to try to get them to appreciate what we call evidence-based science. And the evidence tells us that the vaccines—particularly for measles—are very safe and highly effective.”
NIAID continues to underscore the importance of getting vaccinated to protect everyone from disease.
“Herd immunity means that when a certain percentage of the population is protected by vaccination, it boxes the virus in and does not allow the virus to freely circulate in society,” Fauci explained. “For measles, you need somewhere between 92-95 percent of the population to be vaccinated to get full community protection.” Once we fall below this percentage, “then the herd immunity shield is dampened a bit and that is how people in the community start getting infected.”
So stay current on vaccines, avoid or limit close contact with contagious people and frequently wash your hands. The old adage remains: when it comes to viruses, prevention is the best medicine.