You can feel sick even if the virus is under control.
If my husband and son never tested positive, why did they feel sick? Even if a vaccinated person doesn’t have much virus in their body, they can still have powerful Covid symptoms, the experts told me. That’s because many illness symptoms — fever, malaise, runny nose, fatigue — are actually caused by the immune system’s response to the virus, rather than the virus itself, Dr. Gronvall said.
And as for why I felt fine, Dr. Morrison said that perhaps my immune system fought off the incoming virus so quickly that I didn’t even have a chance to feel sick. “It sounds to me like you were definitely exposed,” Dr. Morrison told me. But, she explained, maybe I had high levels of vaccine antibodies or immune cells called T cells that were able to kill the invading virus before it had a chance to alert the parts of my immune system that would incite symptoms.
All this said, nobody really knows what happened to me, my son or my husband. When it comes to understanding how Covid-19 affects the body, “there are so many open questions,” said Raul Andino, a virologist at the University of California, San Francisco, and people can have different experiences for many different reasons. For instance, Dr. Andino said, it’s possible that the virus was replicating in parts of my husband’s or my son’s body that the tests didn’t reach. Research suggests that the coronavirus can replicate in the pancreas, heart, brain, kidneys and other organs, although vaccination may reduce the chance that the virus spreads outside the respiratory system.
My family is not the only one that has had the bizarre experience of developing coronavirus symptoms but repeatedly testing negative. Dr. Andino said that he and his colleagues have been conducting studies in which they follow and repeatedly test entire households after one person in the home tests positive for Covid-19. “What we see is exactly what you described — that some people in the household don’t test positive,” even though they have symptoms, he said. When I asked my Instagram followers if they’d had an experience like my family’s, I got dozens of “yes” replies and stories that sounded a lot like ours.
June 7, 2022, 1:02 p.m. ET
Most people with Covid-19 exposure and symptoms will test positive, eventually.
The experts I talked to also made a really important point: There’s a difference between never testing positive and not yet testing positive. My husband and son continued to test themselves for a week after developing symptoms, so my sources said it’s unlikely they were ever going to test positive. But many people only test for a couple of days and, frustratingly, you can’t make clear conclusions from just a couple of negative tests.
As I said earlier, when people are vaccinated against Covid-19, their immune systems are primed to fight it quickly, and they often develop symptoms earlier than unvaccinated people do — a few days before they can test positive. So when people only test a few days after developing symptoms, their negative results don’t necessarily mean they don’t have Covid-19. Yet some people assume at that point that they don’t have the coronavirus and stop taking precautions. “They may relax mitigation measures when they are still shedding quite a bit of virus,” Dr. Gronvall said.
Given these findings, Dr. Gronvall said that, ideally, people who have had two or three vaccine doses should test once they start developing symptoms but continue to test on day four or five of symptoms, as tests that come back negative before then may be falsely reassuring. To do this, however, you need to have access to lots of tests. Thankfully, you can now get a third round of free Covid-19 tests through the U.S. government, and there may be free testing sites near you, too.