Johannesburg : A study conducted by South African scientists suggested that the Omicron variant could displace the Delta variant. The infection with the new variant boosts immunity to the older one. The study which is yet to be peer-reviewed, found that people who were infected with Omicron, especially those who were vaccinated, developed enhanced immunity to the Delta variant.

"The increase in Delta variant neutralization in individuals infected with Omicron may result in decreased ability of Delta to re-infect those individuals," the scientists who conducted the study said. The analysis enrolled 33 vaccinated and unvaccinated people who were infected with the Omicron variant in South Africa.

The results of the study are "consistent with Omicron displacing the Delta variant, since it can elicit immunity which neutralizes Delta making re-infection with Delta less likely," they said.

Alex Sigal, a professor at the Africa Health Research Institute in South Africa, said on Twitter on Monday that if Omicron was less pathogenic as it looked to be from the South African experience, "this will help push Delta out".

According to an earlier South African study, there is reduced risk of hospitalisation and severe disease in people infected with Omicron compared with the Delta variant, though the authors say some of that is likely due to high population immunity. read more

South Africa also recalled rules that no longer required people without symptoms of COVID-19 to isolate or test if they have been in contact with a positive case, the government announced on Tuesday, saying an amended circular will be re-issued. Only those people who developed symptoms needed to get tested and that those with mild symptoms should isolate for eight days and severe cases for 10 days. All quarantine facilities outside the home would be stopped, while contact tracing efforts would also be scrapped aside from in specific scenarios such as cluster outbreaks.

Last week the health ministry said that asymptomatic individuals who had been in contact with a case of COVID-19 no longer had to isolate but should monitor for symptoms for 5-7 days and avoid attending large gatherings.

The reason for the revision was based on a number of scientific factors including the fact that, most people have vaccinated with at least one vaccine dose and developed some level of immunity. This has contributed to the current low hospitalisation and high recovery rates, the department said.

The country has led the continent in terms of COVID-19 cases and deaths as well as vaccinations, with 3.42 million cases reported and 90,854 fatalities. Cases started declining this week, with 7,216 new cases and 25 deaths reported in the past 24 hours.

Source : Reuters