COVID-19 reinfection likely for unvaccinated: Study

Researchers from Yale University and the University of North Carolina in the US found that strong COVID-19 protection after recovering from the virus does not last very long, adding that a person may be reinfected in three months or less.

Researchers and doctors have been actively trying to study and understand the nature of the COVID-19 virus since the pandemic’s onset, with many pondering how long-lasting the immunity provided by an infection would be.

“Reinfection can reasonably happen in three months or less. Therefore, those who have been naturally infected should get vaccinated. Previous infection alone can offer very little long-term protection against subsequent infections,” the report’s lead author and professor of Biostatistics at Yale Jeffrey Townsend, said in a statement issued by the university.

The authors of the study titled “The durability of immunity against reinfection by SARS-CoV-2: a comparative evolutionary study” analyzed reinfection and immunological data collected from close viral relatives of SARS-CoV-2, the virus that causes COVID-19.

In addition to this, they also included immunological datasets from both Middle Rast Respiratory Syndrome (MERS) and SARS-CoV-1.

“We tend to think about immunity as being immune or not immune,” said co-leader of the study Alex Dornburg, who is also an assistant professor of bioinformatics and genomics at the University of North Carolina at Charlotte.

“Our study cautions that we instead should be more focused on the risk of reinfection through time,” he added.

Reinfections to become more common with new variants

While COVID-19 reinfections are somewhat common, the research team cautions that such events will likely become more common as new and more contagious variants emerge.

“As new variants arise, previous immune responses become less effective at combating the virus. Those who were naturally infected early in the pandemic are increasingly likely to become reinfected in the near future.”

The research also found that the Risk of reinfection associated with the coronavirus was very similar to that of endemic coronaviruses.

“Just like common colds, from one year to the next you may get reinfected with the same virus. The difference is that, during its emergence in this pandemic, COVID-19 has proven to be much more deadly,” Townsend explained.

“Due to the ability of SARS-CoV-2 to evolve and reinfect, it, too, is likely to transition from pandemic to an endemic disease,” said Dornburg.

“A hallmark of the modern world is going to be the evolution of new threats to human health. Evolutionary biology — which provided the theoretical foundations for these analyses — is traditionally considered a historical discipline. However, our findings underscore its important role in informing decision-making, and provide a crucial stepping stone toward robust knowledge of our prospects of resistance to SARS-CoV-2 reinfection,” Townsend concluded.