(The Hill) — Surgeon General Vivek Murthy announced Friday that he has tested positive for COVID-19, days after he said that his 4-year-old daughter had the virus. 

Murthy wrote on Twitter that his wife and his 5-year-old son were also positive for the virus and had “mild symptoms.” His daughter is “doing OK” and has an improving fever, he added.

Murthy used the occasion to reflect on what it means to get the virus after being careful. 

“When you’ve been as safe as you can, getting COVID-19 can be frustrating and disappointing,” he wrote. “I’ve felt that. It can also be a source of shame. Many people assume you must have been careless to get sick. Our safety measures reduce risk but they can’t eliminate risk. Nothing can.”

He also pointed to the power of vaccinations. 

“One major source of peace of mind for us: we and our son are vaxed/boosted,” he wrote. “Vaccines are very effective at saving our lives and keeping us out of the hospital. As parents, I can’t tell you how reassuring it is to know we’ll be able to care for our kids even if we get infected.”

Murthy’s 4-year-old daughter is too young to be vaccinated, and the timeline for authorization of the vaccine for that age group was recently pushed back to collect more data on a third dose. The delay has been a source of frustration for some parents. 

“I wish a vaccine was available for my child and for all kids <5,” he wrote earlier this week. “It would protect kids and help parents. Unfortunately, more data is still needed from clinical trials for the FDA to make a full assessment. I know a safe, effective vaccine for <5s remains a top priority for them.”