When my 13-year-old son was diagnosed with covid-19 in April, after getting it from me, one of my friends reached out via email.

“Look on the bright side,” she wrote. “Now he’ll have antibodies. When the kids go back to school, you won’t have to worry.”

At the time, I hoped my friend was right. I wanted to believe that the silver lining to our household being exposed to the novel coronavirus is that we’d be armed with some kind of superhero powers that would keep us free from future bouts of the virus, free from parental fretting. And for a brief time, it felt as if we were.

But now as a new school year approaches, and as my household has gotten to know this virus in ways we wish we hadn’t, the optimism has waned.

If getting covid-19 myself and watching a child battle covid-19 have taught me anything, it’s that the virus is complicated. That getting it and getting through it doesn’t make you feel powerful — but powerless. That when it comes to the coronavirus, there are often more questions — more worries and gray areas — than there are concrete answers or anything resembling a sense of peace.

In the spring, I wrote in this column about what happened as our family of six came to terms with my covid-19 diagnosis. I chose not to write about my son because I was hoping there was nothing much to write about.

After my diagnosis, my husband and I worked like crazy to keep our four kids away from me in our New York City apartment, in the hopes they’d remain covid-free. Within 10 days, our three oldest children ran fevers that lasted just 24 hours. When their fevers disappeared, we thought we’d dodged a bullet.

But then our oldest son’s fever came back. And it wouldn’t leave. He was formally diagnosed with covid-19 by our pediatrician in early April. For four weeks, the fever stayed. Some days it climbed as high as 103. Most days it hovered at 100 and 101.

My son lost weight. He grew pale. He developed red rings around his eyes. He went from eating us out of house and home to having no appetite at all.

He was prescribed azithromycin to combat the fever and pain in his chest, which helped. But he was wiped out. His favorite activities before covid included playing on his PlayStation 4 and texting his friends. But the virus left him so weak some days he didn’t even want to look at his phone. (This may not sound like a big deal — but if you are a parent of a 21st-century teen or tween, you know that when your child is too weak to take an interest in Fortnite, there’s something wrong.)

It’s weird that it was our oldest who got covid-19. He’s a typical teenage boy who likes to remind his parents just how uncool we are, and he’d been the only one of our kids who hadn’t snuggled with me in the days before my diagnosis, who waved away my attempts at hugs. Just before my symptoms set in, our youngest child had snuggled with me a great deal, as had my husband. And neither of them got sick.

Our second oldest son, who has asthma, was the child we had worried would be most vulnerable. And his fever was gone within 18 hours, his breathing never affected.

Instead, our oldest — the one who’d had no underlying health conditions, who loves Little League and all kinds of sports — was the one most affected by it. It was just one of many mysteries we’d discover about covid-19. There were more surprises to come.

Even once you test negative for covid-19 after having it, the symptoms can linger. In my case, I still have burning lungs. I looked for the same symptom in my son and was relieved to find he had no cough, no lung issues.

But then my son’s headaches began. Doctors call them covid headaches. My son never had headaches before covid. He gets them now, some so strong he needs to go back to bed. And he’s still pale, and has a significantly reduced appetite.

He’s part of a months-long study at New York-Presbyterian/Columbia University, looking at those who have had covid-19. At each visit, before his blood is drawn and spit samples are collected, he’s asked questions about how he’s feeling.

“I’m feeling better,” he told the team on his last visit. “But will the dizzy spells go away?”

The researcher looked at him gently. “We’ve been hearing about dizzy spells from other patients.”

“Will they go away?” he pressed.

“We hope so.”

The answers are no more definitive when I ask if my son can get the virus again.

My son and I have antibodies. We’d hoped that meant we can’t get covid-19 in the future. But all of the researchers we’ve talked to tell us the same thing — that while antibodies are believed to give us some level of protection, they’re no guarantee and the protection may last only a few months. If the virus sufficiently mutates in coming months, they warn, we could catch a new strain, regardless of what antibodies we picked up from our first go-round.

Then there are the other things researchers aren’t sure about when it comes to long-term effects of the coronavirus. They don’t know if it will impact fertility in the young people who’ve contracted it. They don’t know if it is a virus that remains in the system, and could be triggered by stress or exhaustion for years, even decades, to come.

Five months after our covid-19 journey began, we count our blessings. My husband and I know people who have died of the virus. We are grateful to be alive, grateful to see our son up and about and having perfectly healthy and vigorous arguments with his younger siblings, to see color returning to his cheeks. When he recently asked me for a late-night peanut butter and jelly sandwich, I jumped for joy, elated that his appetite appears to be returning.

But for those who think, like I once did, like my well-intentioned friend did, that the virus comes and goes and leaves no lasting scars in children and brings with it a silver lining of immunity, please think again. My son thankfully now tests negative for covid-19. But its impact is a lasting one.

We recently filled out a school survey, electing to send our children to in-person school for two days a week this fall, rather than keep them home full time. We are big believers in our kids getting back out there, interacting with their peers, living their lives as fully as possible.

Still, we worry. Some parents enter the school year worried about the impact of a virus they don’t know. In our case, we enter it acutely aware of the virus we’ve gotten to know too well.

Mary Pflum Peterson is a television journalist and the author of “White Dresses: A Memoir of Love and Secrets, Mothers and Daughters.” She and her husband are raising their four children in New York.

Follow On Parenting on Facebook for more essays, news and updates, and join our discussion group here to talk about parenting and work. You can sign up here for our newsletter.