The pandemic is to blame for the steady rise in RSV cases



CNN

The behaviors that have helped protect us from Covid-19 over the past 2 1/2 years — lockdowns, physical distancing, wearing masks, washing hands — are likely behind an “unprecedented” rise in RSV infections this year, scientists say.

These factors may have pushed other seasonal respiratory viruses out of whack around the world.

“As long as we’ve had a record of RSV and other respiratory diseases in the United States, there have been very regular patterns of outbreaks,” said Rachel Baker, an epidemiologist and assistant professor at Brown University.

“RSV appears every year in the late fall/winter and these outbreaks are mostly in young children. Then it goes away again in the spring/summer months and reappears the following winter,” Baker said. “It’s very regular and predictable” – until it isn’t.

Cases of RSV, or respiratory syncytial virus, in the United States began to appear in the spring and are now 60% higher than the peak week of 2021. A CNN analysis shows that this is probably a minimum count.

In the US, the number of flu cases has also increased slightly earlier than usual. A few schools have experienced high absenteeism, and medical offices say they’re seeing sick people with other respiratory viruses that don’t fit the usual patterns.

In respiratory infections, for example, there have been similar unusual patterns adenovirus, parainfluenza and rhinovirus in other countries as well.

Scientists believe that the actions of the pandemic have had unparalleled consequences.

“The level of social change that has occurred with the Covid pandemic is unprecedented today,” said Dr. Kevin Messacar, an associate professor in the Department of Pediatrics at Children’s Hospital Colorado.

Like Covid-19, RSV and influenza are spread through droplets released into the air when people cough or sneeze. Drops also linger for hours on frequently touched surfaces such as doorknobs and light switches.

So those who washed their hands and disinfected surfaces, wore masks and kept their distance from others, did more than stop the spread of the coronavirus.

“While those interventions were great at limiting the spread of Covid-19, they did a very good job of reducing the spread of other respiratory diseases such as RSV and influenza,” Baker said.

The 2020 and 2021 seasons saw a sudden drop in RSV cases and hospitalizations, studies have shown, as well as unusual flu seasons.

“It was really striking,” Baker said.

But as vaccines and treatments for Covid-19 became available, more people began to return to school and work and interact without masks. They also started sharing theirs.

Pandemic behaviors created an “immune gap” or “immune debt,” which makes more people in the U.S. vulnerable to diseases like RSV.

Children develop a natural immunity to viruses when exposed to them. Most children catch RSV before the age of 2, says the US Centers for Disease Control and Prevention. Newborns receive passive protection from their mothers, as they pass antibodies through breast milk.

But for a couple of years, there was little chance of children born during the pandemic or those around them catching RSV, or other viruses for that matter. Their immunity was weakened or never developed. So when those little ones and their parents started interacting with others, they were more likely to get sick.

“Decreased exposure to endemic viruses created an immune gap: they avoided infection and thus lacked pathogen-specific immunity to protect against future infections,” Messacar and Baker wrote in a commentary published this summer in the medical journal The Lancet.

Hospitals were warned to be flexible and prepared for unpredictable respiratory disease seasons because of this gap.

“We knew it was inevitable that these diseases would come back,” Messacar told CNN.

The comment warned of a wide range of infections that will include infants who have not been exposed to the virus and newborns whose mothers have been unable to pass on antibodies because they have not been in contact with the germs.

“We’re seeing it roll out really well now,” Baker said. “And it’s not just babies that are striking, usually with that first birth cohort. It’s also causing infections in older children.

“That’s how infectious diseases work,” he added. “When you have more cases, they create more cases and you get this point.”

Baker and Messacar don’t believe this early-season pattern with RSV is sustainable, but it could take some time to return to its predictable cycle.

“We’re in a rare period right now, but I think in the next few years we’ll start to see those regular outbreaks, well, depending on what happens with Covid,” Baker said. If the coronavirus is bad enough that more lockdowns are necessary, it could throw off the seasonality of other viruses again.

With viruses like the flu, there are more variables, Messacar said.

There’s no vaccine to prevent RSV, but if it’s against the flu, so if the flu vaccine matches the strain in circulation and enough people get it, the country could avoid a spike in RSV cases like it’s seeing now.

Scientists are working on an RSV vaccine, but it won’t arrive in time to help this season.

In the meantime, there are a few things that need to be done to limit the spread of RSV, and they will be very popular.

wash your hands Keep frequently used surfaces clean. Cough or sneeze into your hands rather than your hands or elbow. Boost your immunity by getting plenty of sleep and eating a healthy diet. Wear a mask, especially when you are sick. And most importantly, if you are sick, stay home.

“All of these non-pharmaceutical interventions work, clearly, and the more we can do to keep any cases of these viruses down, the better,” Baker said.