Cases of reinfections are more likely with the emergence of the Omicron Covid variant, South African researchers have said.
Apreliminary study by South African researchers has indicated that the newly detected Omicron variant could be associated with a higher risk of reinfections.
The study is based on data from the country's health system and provides the first epidemiological evidence of the new variant's ability to evade immunity from prior infection. The paper was uploaded to a medical preprint server and has not yet been peer-reviewed, AFP reported.
Juliet Pulliam, director of the South African DSI-NRF Centre of Excellence in Epidemiological Modelling and Analysis, said, "We find evidence of increased reinfection risk associated with emergence of the Omicron variant, suggesting evasion of immunity from prior infection."
"Recent reinfections have occurred in individuals whose primary infections occurred across all three waves, with the most having their primary infection in the Delta wave," she said in a series of tweets.
MORE DATA NEEDED
However, she cautioned, that the study is in its initial stages and more data is required for better understanding. She said, "Immune escape from prior infection, whether or not Omicron can also evade vaccine derived immunity, has important implications for public health globally, but there is still a lot we don’t know. Data are also urgently needed on disease severity associated with Omicron infection, including in individuals with a history of prior infection."
UNSURE IF OMICRON EVADES IMMUNITY FROM VACCINES
She also said it is not clear if the Omicron variant could evade vaccine-derived immunity. She said, "We do not have information about the vaccination status of individuals in our data set and therefore cannot make any assessment of whether Omicron also evades vaccine-derived immunity."
Pulliam said the studies hint at Omicron's ability to infect previously infected individuals. She said, "These findings suggest that Omicron’s selection advantage is at least partially driven by an increased ability to infect previously infected individuals.
Omicron is classified by the World Health Organisation as a “variant of concern” as scientists work to determine how it may compare with the predominant delta variant in terms of transmissibility and severity. Scientists are also studying the degree to which existing vaccines and therapies protect against Omicron.
Scientists in South Africa first reported it, but the samples came from several countries in southern Africa. And health officials in the Netherlands now say it was found there prior to the South Africa detection, PTI reported.
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