Covid at home: why only some people test positive

By on June 6, 2022 0

If my husband and son never tested positive, why did they feel sick? Even if a vaccinated person doesn’t have a lot of virus in their body, they can still have strong Covid symptoms, the experts told me. Indeed, many symptoms of the disease – 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 to why I felt good, Dr Morrison said maybe my immune system fought off the incoming virus so quickly that I didn’t even have a chance to feel sick. “It looks to me like you’ve definitely been 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 cause symptoms.

That said, no one 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 may have different experiences. for many different reasons. For example, Dr. Andino said, it is possible that the virus has reproduced in parts of my husband’s or my son’s body that the tests did not reach. Research suggests the coronavirus can replicate in the pancreas, heart, brain, kidneys and other organsalthough vaccination can reduce the chances that the virus spreads outside the respiratory system.

My family aren’t the only ones who have had the bizarre experience of developing coronavirus symptoms, but have repeatedly tested negative. Dr Andino said he and his colleagues had conducted studies in which they repeatedly followed and tested entire households after someone in the home tested positive for Covid-19. “What we are seeing is exactly what you described – that some people in the household are not testing positive,” even though they are showing symptoms, he said. When I asked my Instagram followers if they’d had an experience like my family’s, I received dozens of “yes” responses and stories that sounded a lot like ours.

The experts I spoke to also made a very important point: there is a difference between never testing positive and not yet positive test. My husband and son continued to test themselves for a week after developing symptoms, so my sources said it was unlikely they would ever test positive. But many people only test for a few days and, frustratingly, you can’t draw clear conclusions from just a few 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 – a few days before they cannot 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 can relax the mitigations while they’re still shedding quite a bit of virus,” Dr Gronvall said.

Given these results, Dr Gronvall said that ideally people who have received two or three doses of the vaccine should test once they start to develop symptoms, but continue testing on day four or five of symptoms. , because tests that come back negative before that can be falsely reassuring. To do this, however, you must have access to many tests. Fortunately, you can now get a third round of free Covid-19 tests by the US government, and there may be free test sites near you too.