A new study suggests that immunity developed against Omicron can also protect against Delta, justifying how omicron outpaced Delta as the most dominant coronavirus variant.
Researchers, who observed how immunity from the highly infectious Omicron variant performs in 33 participants in South Africa, discovered that the ability to neutralise Omicron rose 14 times after 14 days, while immunity against Delta was enhanced four times.
This was detected in previously vaccinated and unvaccinated individuals who were infected with COVID-19 in the Omicron infection wave soon after symptoms started.
Researchers think this sets a positive tone in phasing out variants fostering the burden of coronavirus disease, ensuring re-infections with Delta become less likely.
This also implies that while Omicron displaces Delta, it takes over re-infections in individuals with weak Delta infections and then counteracts itself.
“The increase in Delta variant neutralization in individuals infected with Omicron may result in a decreased ability of Delta to re-infect those individuals. Along with emerging data indicating that Omicron, at this time in the pandemic, is less pathogenic than Delta, such an outcome may have positive implications in terms of decreasing the Covid-19 burden of severe disease,” the study states.
End of acute phase?
The study has not been peer-reviewed but if it hatches out, it could see the beginning of COVID-19 transition into a less harmful disease as Omicron dominates further, analysts suggest.
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According to a study led by researchers at South Africa’s National Institute for Communicable Diseases, individuals infected with Omicron between October and early December 2021 had lower odds of being admitted to the hospital compared to those infected with other variants – equivalent to a roughly 80 percent reduction in risk.
The study, which has not yet been peer-reviewed, also looked at disease severity once someone was admitted to hospital with Omicron, compared to known Delta infections, and identified a roughly 30 percent reduction in the risk of severe complications.
Other studies suggest that Omicron spares the lungs, considering that upper respiratory infections are much less dangerous than infections that embed themselves in the lower respiratory tract, as previous COVID strains have.
However, there might be downsides when it comes to future protection, George Abraham, president, American College of Physicians said in a monitored report.
He said weaker infections tend to lead to weaker and shorter-lived immunity. “People with more severe illness tend to get more robust immunity, which may last longer. People who have milder infections tend to have less robust immunity,” he adds.
That means there’s a chance that people who catch Omicron and experience it as a mild upper respiratory illness might not gain much protection if a more severe variant emerges.
And getting a mild or even a severe case of COVID won’t protect forever. Any immunity from an Omicron infection, or from any other variant, is fleeting, Abraham says, noting that the bodies destroy antibodies over time, and viruses continually mutate.
Eventually, the combined effects of a declining immune response and future mutations will allow the virus to elbow its way back into previously-infected cells.
This occurs with the common cold, infects over and over. People who’ve already caught the virus can catch it again after some time passes, as can people who’ve been vaccinated.
No spike in Omicron cases will change the potential for breakthrough cases, apparently. But we can hope that when most people have some level of immunity, either from vaccination or previous infection, relatively mild cases will become the norm and the spread will slow, some analysts say.