The researchers reviewed 65 studies from 19 countries up to September 2022, meaning some covered the period when Omicron swept across the world.
Omicron proved to be more contagious than previous strains, but less severe.
People with natural immunity from a pre-Omicron variant saw their protection against reinfection wear off much more quickly for the early Omicron strains, dropping to 36 per cent after 10 months, the study said.
“Vaccines continue to be important for everyone in order to protect high-risk populations such as those who are over 60 years of age and those with comorbidities,” study co-author Caroline Stein of the IHME said in a statement.
The study also gives a more accurate picture of what COVID-19 might look like in the future, as more vaccinated people are reinfected, acquiring “hybrid immunity”.
“In the long run, most infections will occur in people with strong protection against severe disease because of previous infection, vaccination, or both,” said Cheryl Cohen, an epidemiologist at South Africa’s National Institute for Communicable Diseases.
“These results suggests that, similar to other human coronaviruses, there might be a low seasonal hospitalisation burden” associated with COVID-19, Cohen said in a Lancet commentary.
For all the latest world News Click Here
