The possibility of coronavirus reinfection was a concern since the first reports of people getting sick again popping up in 2020 – while many around the world were still in isolation. But so far there has been relatively little data on how widespread it is.
The first large-scale inquiry to address the question was published in The Lancet this week, and it found that the vast majority of people who have had COVID-19 are indeed protected from catching it again – for at least six months. However, people 65 years and older are much more likely to have recurrent infection than younger individuals.
The researchers analyzed data from Denmark’s national COVID-19 testing program, which offered free PCR testing to about 4 million people living in the country. Overall, they found that a very small percentage of the population – 0.65% – experienced reinfection.
Those 65 years and younger, the coronavirus once offers 80% protection against reinfection. But for people 65 and older, it only gave about 47% protection against COVID-19, further emphasizing how dangerous this disease can be for older adults.
“As older people also experience more severe disease symptoms and die sadly, our findings show how important it is to implement policies to protect the elderly during the pandemic,” said Steen Ethelberg, author of the study by the Statens Serum Institut. in Denmark, said in a statement. “Given what is at stake here, the results highlight how important it is for people to take the measures to keep themselves and others safe – even if they have had COVID-19.”
“Given what is at stake here, the results highlight how important it is for people to adhere to the measures that keep themselves and others safe.”
– Steen Ethelberg, researcher at Statens Serum Institut in Denmark
What this study means for us (and the future of the pandemic)
Overall, this news is positive, but it also underscores the need for continued vigilance. Many factors can still play a possible role in getting sick.
The emergence of different variants is one of them. Coronavirus re-infection has become a particular concern in recent months as new variants have begun to spread around the world.
In a vaccine study in South Africa – where a variant does the spread that experts fear is more contagious and the current vaccines may be less effective – in 2% of the people who previously had another variant of the coronavirus infected, found new infections.
The large new study from Denmark did not investigate the role of variants in reinfection, given the time frame of the research. It therefore offers no clues as to whether it is more likely that someone has come down with COVID-19 more than once.
Previous case studies of people who have been re-infected have been of concern because they have suggested that it is possible to become ill a second time. This was the case with an otherwise healthy 25-year-old man in Nevada who tested positive for COVID-19 last spring, recovered and then fell ill again. He needs hospitalization for the second time. But even when the first reports surfaced and drew significant news coverage, researchers were careful to point out the scarcity of the outcome.
Since the new study on reinfection was not conducted in the United States, it is unclear whether the findings apply here in the same way. But overall, researchers are optimistic that most people who get COVID-19 will not experience reinfection soon after. And they continue to study immunity, both after infection and after vaccination. It is unclear at this stage how long immunity lasts after a person receives a COVID-19 vaccine.
All of this underscores the continuing need for basic preventative measures, even as cases of coronavirus begin to decline nationwide.
The Centers for Disease Control & Prevention recommends that people who have had COVID-19 be vaccinated as soon as it is available, mainly because they are less likely to become infected again if they come in contact with the virus.
Continued mask wear is also essential as qthe question remains as to the extent to which those who recovered from COVID-19 may spread it to others if they are exposed again. In addition, wearing the mask helps to reduce the small chance that a person gets the virus more than once.
Earlier this month, the CDC released new guidelines that say fully vaccinated Americans can safely congregate inside without wearing masks or social distances, and it offers a promising look at how restrictions are likely to weaken as more shots are fired into the arms. go. But for now, it’s a race against the clock to ensure millions of Americans are vaccinated, as variants continue to spread.
Experts are still learning about COVID-19. The information in this story is what was known or was available at the time of publication, but guidance may change as scientists discover more about the virus. Consult the Centers for Disease Control and Prevention for the most up-to-date recommendations.