Back to school also means the return of seasonal viruses. 

And as families prepare their children for new classes and routines, they should also consider ways to protect them from the inevitable uptick in supergerms.

“As we head into the colder months, we’re expecting to see the usual spike in respiratory viruses like flu, COVID and RSV. Parvovirus B19, which has been around for a long time, also seems to have had a comeback,” said Kay Leopold, M.D., pediatric infectious diseases physician at University of Michigan Health C.S. Mott Children’s Hospital.

“The good news is we have great tools to help reduce young people’s risks of getting severely sick from these illnesses. But it’s also a good time to remind kids to be conscious of hygiene habits we know prevent the spreading of germs as they get back to close-knit environments at school.” 

Leopold shares more about what infectious disease experts expect to see with viruses this season, what’s new with vaccinations and steps parents can take to keep children as healthy as possible.

Parvovirus B19 or “slapped cheek disease”

A respiratory seasonal virus called parvovirus B19 has been on the rise in the United States, according to the U.S. Centers for Disease Control and Prevention. 

It’s sometimes called “fifth disease” because it’s part of a group of childhood illnesses that cause rashes, Leopold says.

Classic symptoms usually come in two parts. 

The first stage may involve fever, body aches, weakness and fatigue, which last for a few days and mark the most contagious window. 

About a week later, kids may classically also get a red rash on their face that looks like a “slapped cheek” or a lacy looking rash on their arms and legs. 

By the time the rash appears, Leopold notes, they have likely passed the contagious period.

Most people get the virus only once during childhood. 

“The antibodies people get after an infection should be preventative against reinfections,” she said. “Similar to viruses like measles, once you get it, it’s highly unlikely that you’d get it again in the future.”

While kids often experience minor symptoms, there are rare cases of severe disease, such as associated myocarditis that causes inflammation and weakness of the heart muscle, or hepatitis, which leads to inflammation in the liver. 

The two highest risk groups are pregnant people and patients with blood diseases. 

Doctors have reported unusual numbers of parvovirus-related complications among the two high risk populations this year.

“People who are at higher risk for severe disease should talk to their doctors if they’ve been exposed to the virus or have symptoms,” Leopold said.

Parvovirus B19 is spread through respiratory droplets just like the common cold, so the best prevention strategies include regular hand washing, covering mouths when coughing or sneezing, disposing of tissues promptly and not sharing food or drinks, she says. 

RSV

In 2023, the U.S. Food and Drug Administration approved a drug to protect infants and high risk toddlers from respiratory syncytial virus, or RSV – the most common cause of hospitalization for babies in the U.S.

Last year, the AstraZeneca drug, called nirsevimab or Beyfortus, was in limited supply and needed to be prioritized for infants at the highest risk for severe RSV. 

The highly contagious seasonal virus usually causes mild, cold-like symptoms but may also lead to severe sickness, particularly in babies or children with weakened immune systems.

With no supply problems anticipated for the upcoming season, Leopold says it’s now recommended for all newborns and infants under eight months old entering their first RSV season and for high risk infants and toddlers aged 8-19 months during their second RSV season.

A 2024 study showed that nirsevimab was 90% effective at preventing RSV-associated hospitalization for infants. 

Pregnant people also have the option to take a separate vaccine between their 32-36 weeks of pregnancy to protect their babies during RSV season. 

Both options provide passive immunity to babies, either providing antibodies directly after birth or through the placenta prenatally, Leopold says.

“We recommend that people who are pregnant between September and January receive the RSV vaccine,” she said. 

“Babies born during RSV season to people who did not receive the RSV vaccine during pregnancy can receive nirsevimab.” 

Only in rare cases is it recommended that babies get both forms of protection, such as if the delivering parent didn’t have a good response to the vaccination because they were immunocompromised, she added.

But pregnant people who have received a dose of maternal RSV vaccine during a previous pregnancy aren’t recommended to receive additional doses during future pregnancies.

“This is a common respiratory virus that sends tens of thousands of children to the hospital every year and as a pediatrician I’m thrilled to see an option to protect the youngest and most vulnerable patients,” Leopold said.

“We’ve seen hospital beds fill up completely in winter because of RSV cases in infants. Having a baby hospitalized for a viral infection is traumatizing for families. We want to keep babies safe, out of the hospital and as healthy as possible.”  

Flu

This year’s updated flu vaccine is going trivalent, which means it protects against three different strains expected to be circulating this season.

It’s recommended for everyone aged six months or older, with the peak vaccination window usually falling between September and October for the best protection timing, Leopold says. 

If it’s a child’s first season receiving the flu vaccine, they’ll need two doses one month apart, she says. 

But after a year, a child can get on the regular vaccination schedule.

“Vaccines reduce the risk of hospitalization or death from these illnesses, and we strongly recommend that everyone get vaccinated,” she said.

COVID

As COVID variants continue to evolve, a new formula COVID vaccine is now available this fall, Leopold says. 

A dose of the updated 2024-2025 COVID vaccine will be recommended for everyone aged six months or older. 

Infants younger than six months, who are among groups hit hardest by the virus, can receive COVID protection through a maternal vaccine during pregnancy. 

She recommends kids getting the vaccine in the fall, with similar timing to the flu vaccine. 

But if someone has had a recent COVID infection, they should wait three months after infection for vaccination for an improved immune response to vaccination. 

If someone has had a recent COVID vaccine, they should wait a minimum of eight weeks before receiving the 2024-2025 COVID vaccine.

“As much as we’d love to not have to worry about COVID anymore, we saw a big surge in cases this summer and know it’s still a risk this season,” Leopold said.

Data shows that fewer people got the last updated COVID vaccine when it became available, with less than a quarter of adults and about a seventh of children receiving the updated shot. 

While most people now have some immunity against COVID, this wanes with time and the virus keeps changing, Leopold says, making it more important that communities boost their immunity with updated vaccines. 

“Kids do get it and even mild infections can spread to others who may be more immunosuppressed or at risk of a severe infection,” she said. 

“Higher immunization numbers help protect the broader community.” 

She says parents should schedule vaccinations in ways that are most convenient to them, but that children can safely receive multiple vaccines – including COVID and flu – at the same time.

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