Mandy Moore felt "super helpless" after her sons were diagnosed with RSV

She told PEOPLE magazine: "It was a super helpless feeling.

"I mean, we were lucky in the sense that it didn't include a hospital trip, but my husband and I were still really shook and very concerned."

RSV is a common cause of coughs and colds, and while infections usually get better by themselves, they can be serious for babies.

For babies, RSV can cause bronchiolitis, or even pneumonia.

Mandy and her husband Taylor Goldsmith also have daughter Loui Everett together, who was born in September 2024.

The This Is Us star said: "Even though Lou was going to be born in September, which is technically before the start of RSV season, which runs from fall to spring in the majority of the country, we were determined to find some sort of solution, so we talked to Dr. Danny Bruckner, our pediatrician, and he was adamant that no matter when a baby is born, even if it's before or during the RSV season, it's really, really important to have an extra layer of protection."

Mandy was "relieved" when their daughter Lou was able to get Beyfortus, which is a monoclonal antibody medication for infants and young children.

She said: "Lou was lucky to get the very first appointment on October 1. She got immunised, and I was unbelievably reassured and relieved, knowing that she was going to be protected through her first RSV season.

"I mean, as a parent, I feel like it really is the best possible situation - you learn from your mistakes, and I feel like this go-around, I was even more prepared."