Medical Xpress – A team of researchers in South Africa has found evidence that suggests people who have been infected with the COVID-19 Omicron variant may be less susceptible to infection from the Delta variant.
The team has written a paper describing their work.
As the global pandemic has progressed, variants have emerged—some more resilient than others.
Thus far, the Delta variant has proven to be the hardiest and because of that has overtaken the original virus as the most widespread of the variants infecting people around the world.
More recently, the Omicron variant has emerged, first in South Africa, then all around the world.
Initial reports indicate that the new variant is much more easily spread than Delta but is less harmful to those infected — also, there has been some evidence that the booster shots given for the original and Delta variants may last for as little as ten weeks against Omicron.
In this new effort, the researchers in South Africa have found some evidence of Omicron infections giving people some degree of immunity from Delta infections … read more.
Omicron infection enhances neutralizing immunity against the Delta variant
medRxiv – Omicron has been shown to be highly transmissible and have extensive evasion of neutralizing antibody immunity elicited by vaccination and previous SARS-CoV-2 infection.
Omicron infections are rapidly expanding worldwide often in the face of high levels of Delta infections. Here we characterized developing immunity to Omicron and investigated whether neutralizing immunity elicited by Omicron also enhances neutralizing immunity of the Delta variant.
We enrolled both previously vaccinated and unvaccinated individuals who were infected with SARS-CoV-2 in the Omicron infection wave in South Africa soon after symptom onset.
We then measured their ability to neutralize both Omicron and Delta virus at enrollment versus a median of 14 days after enrollment. Neutralization of Omicron increased 14-fold over this time, showing a developing antibody response to the variant.
Importantly, there was an enhancement of Delta virus neutralization, which increased 4.4-fold. The increase in Delta variant neutralization in individuals infected with Omicron may result in 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. source