Masks Are Not to Blame for the RSV and Flu Surge Right Now
This year’s flu season is shaping up to be particularly tough, as the current weekly number of cases is extremely high. Meanwhile, doctors are seeing a surge in the respiratory syncytial virus , better known as RSV, which usually causes mild cold symptoms in adults but can be especially dangerous for very young children and the elderly. This surge in RSV has already resulted in an unusually high number of hospitalizations , mostly among young children. These spikes in influenza and RSV infections occur earlier in the year and at higher levels than usual.
There are many unknowns why influenza and RSV are at unusually high levels. However, one thing is certain: “Because we’ve been wearing masks all this time doesn’t mean we’ve harmed our immune system,” said Raiwat Deonandan , an epidemiologist at the University of Ottawa. “Your immune system is not like a muscle where if you don’t use it, you lose it.”
If it’s not because we’ve been wearing masks all year, what do we know about why the flu and RSV season is higher than usual this year?
How does our immune system work?
Our immune system is used much more than we think, even if we don’t get sick. “Our immune system doesn’t atrophy, it doesn’t weaken, it works daily,” said Sabine Vohra-Miller , founder of Unambiguous Science. As Vohra-Miller points out, although respiratory viruses such as influenza are in the 2020-2021 season. decreased, our immune system is constantly exposed to pathogens that are found in our food and water, the vast majority of which never result in illness.
Our immune system also has a very long memory, where it “works like a photosystem,” said Colin Furness , an epidemiologist at the University of Toronto. “It’s very forever.” Our immune system learns to recognize certain infectious agents that it has encountered before.
As we get older, our immune systems begin to weaken, much like photographs shrink with age. However, “in children and in healthy adults, unless you have some kind of immune-compromised health condition, these pictures remain very intact,” Furness said. “It doesn’t matter if you haven’t had the flu in years, your body will react to the flu the same way it did the last time.”
A virus like the flu can only elude the immune system by changing to the point where it can no longer be recognized, while for viruses and pathogens that don’t change very much, like measles or chicken pox, the immune system will be able to fight it the next time the impact occurs, even if it has been for many years.
Flu and RSV are seasonal.
While not being exposed to respiratory viruses during the year will not affect a person’s immune system, the unusually low number of cases in the 2020-2021 season may be one of the reasons why we are seeing such a high number of influenza and RSV cases. “There is some truth to the fact that with pandemic restrictions holding back all kinds of respiratory diseases, we are seeing a resurgence in general,” Deonandan said.
However, this resurgence is due to the seasonality of viruses such as influenza and RSV, and not to the absence of infections that attack the human immune system. As a number of scientists predicted in a 2020 paper , the low number of respiratory infections, combined with the seasonality of these viruses, could lead to higher-than-normal infections in later seasons.
Right now that classes have resumed at the school, “it’s really fueled the viruses in the school environment,” said Pedro Piedra , a virologist at Baylor College of Medicine. All these viruses circulating among schoolchildren have a ripple effect of infecting other members of their social circle, such as their parents, who then spread the virus to their colleagues.
COVID Infections May Affect Our Immune System
One factor that may be contributing to this year’s unusually heavy flu and RSV seasons is the impact of COVID infection on our immune systems. As early evidence suggests , this may play a role. “There are a number of papers suggesting that COVID infection may reduce our ability to fight future infections of various types,” Deonandan said.
This is not a new idea: a number of viruses are known to negatively affect our immune system. One example is the measles virus , which can make our immune system “forget” past infections. As a 2019 study showed, infection with measles can lead to the destruction of 11 to 73% of the antibodies in our body.
It is not yet known how much COVID can reduce our immune system response, who might be susceptible, and what the consequences might be. “A lot of people have had multiple infections that are fine,” Deonandan said. “There just might be a proportion of people who become infected or re-infected and that compromises their ability to fight future infections.”
Take precautions to reduce your risk
Influenza causes 12 to 52,000 deaths per year , and RSV causes 58,000 to 80,000 hospitalizations per year in children under 5 years of age . While this year promises to be a particularly bad one, the risks are well known. “Respiratory viral infections before the pandemic, during the pandemic and after the pandemic will have a significant impact on our health,” Piedra said. “All this is not new.”
The advantage is that there are a number of precautions that can reduce the risk of illness or reduce the severity of these symptoms. This includes getting your COVID shots up to date, making sure you get your flu shot, and taking precautions like wearing a mask when you’re in a public place.