Omicron linked to higher risk of coronavirus re-infection: Study

The team of researchers in South Africa noted that, in contrast, there is no population-wide epidemiological evidence of immunodeficiency associated with beta or delta variants.

NS B.1.1.529 COVID Type, was first detected in South Africa, designated as a Variant of Concern (VOC) by the World Health Organization, the health body’s apex category for concern over coronavirus variants.

Experts believe that the variant contains about 50 mutations. Of these, 32 are in the spike protein, which the virus uses to enter human cells, and 10 are mutations of high relevance.

This is the first data-based study to suggest that Omicron may evade immunity from prior infection.

“Population-level evidence suggests that the Omicron variant is associated with a substantial ability to evade immunity from prior infection. In contrast, there is no population-wide epidemiological evidence of immune escape associated with beta or delta variants,” study The author noted.

In a peer-reviewed study posted to the pre-print repository medRxiv last week, researchers examined whether SARS-CoV-2 reinfection risk has changed over time in South Africa, in the context of the emergence of Beta, Delta and Omicron. Variants.

They used surveillance data on SARS-CoV-2, the virus that causes COVID-19, collected between March 4, 2020 and November 27, 2021, through South Africa’s National Notified Medical Conditions Surveillance System .

Study participants included 2,796,982 individuals with laboratory-confirmed SARS-CoV-2 who had a positive test result at least 90 days before November 27, 2021.

Individuals who tested sequentially positive in an interval of at least 90 days were considered to have suspected re-infection.

Study identifies 35,670 suspected reinfections among 2,796,982 laboratory-confirmed individuals SARS-CoV-2,

“These findings suggest that the selection advantage of Omicron is at least partly driven by an increased ability to infect already infected individuals,” said the South African DSI-NRF Center of Excellence in Epidemiological Modeling and Analysis (SACEMA) , said Juliet RC Pulliam of Stellenbosch University. South Africa.

Pulliam, the study’s corresponding author, tweeted: “Avoiding immunity from prior infection, whether or not Omicron can evade vaccine-derived immunity, has important implications for public health globally, but there is still much that we don’t.” know.”

The study also suggests that the spread of the beta and delta variants of COVID-19 was due to increased communicability rather than the ability to evade immunity.

“We find evidence of a substantial and sustained increase in the risk of re-infection that is tentatively consistent with the timing of the emergence of the Omicron variant in South Africa, suggesting that its selection advantage is at least partly associated with previously infected This is motivated by an increased ability to infect individuals,” the authors said.

The finding has important implications for public health planning, especially in countries such as South Africa with high rates of immunity from prior infections, he noted.

Urgent questions remain about whether Omicron is also able to evade vaccine-induced immunity and the potential effects of reduced immunity to infection on protection against serious illness and death.

“We do not have information on the vaccination status of individuals in our data set and therefore cannot make an assessment as to whether Omicron also confers vaccine-derived immunity,” Pulliam said in a tweet.

“Next steps include the extent of Omicron’s immunity to both natural and vaccine-derived immunity, as well as its transmissibility relative to other types,” he said.