Omicron has 'substantial' ability to evade immunity from previous infection 8 months ago

Omicron has 'substantial' ability to evade immunity from previous infection

"We find evidence of a substantial and ongoing increase in the risk of reinfection"

Reports suggest that Omicron has a "substantial" ability to evade natural immunity developed by a previous Covid infection.


Findings from the world's first real-world study of the variant's effects suggest that Omicron could cause a new wave of infection.

Researchers at South Africa's National Institute for Communicable Diseases (NICD) have warned that their findings could pose serious health implications across the globe.


"Urgent questions remain regarding whether Omicron is also able to evade vaccine-induced immunity and the potential implications of reduced immunity to infection on protection against severe disease and death," the researchers said.

Scientists analysed 2.8million confirmed cases in South Africa since March of 2020, where they found a total of 35,670 reinfections.

Their findings suggest that the risk of reinfection was lower in the Beta and Delta Covid waves than the first wave created by the initial strain of the virus in 2020.

But significantly, they found the risk of reinfection in the current Omicron wave is 2.4 times higher than in the first wave.


It's essential to bear in mind that the research is yet to be peer-reviewed, but these findings will undoubtedly inform Covid policy across the world.

"We find evidence of a substantial and ongoing increase in the risk of reinfection that is temporally consistent with the timing of the emergence of the Omicron variant in South Africa, suggesting that its selection advantage is at least partially driven by an increased ability to infect previously infected individuals," said the researchers.

"Immune escape from prior infection, whether or not Omicron can also evade vaccine derived immunity, has important implications for public health globally."


Similarly, Professor Paul Hunter of The Norwich School of Medicine said: "The implications of this paper are that Omicron will be able to overcome natural and probably vaccine induced immunity to a significant degree.

"But, the degree is still unclear, though it is doubtful that this will represent complete escape."

He added that it is yet unclear whether this also means a higher chance of hospitalisation.

He continued: "With previous variants, epidemiological studies showed that protection against severe disease from other variants was better maintained than protection against infection."

Barry Schoub, chair of the South African government's committee on COVID vaccines, told Sky News that initial reports were "good news".


He added that hospitalisations had increased slightly, but nothing near previous waves of Covid.

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