Omicron Variant Could Help Beat Delta, Study Advice

People recovering from an infection with the novel Omicron coronavirus variant can fend off infections after the Delta variant, according to a new laboratory study led by South African scientists.

If more experiments confirm these findings, they may suggest a less dire future for the pandemic. In the short term, Omicron is expected to generate a spike in cases that will put a huge strain on economies and healthcare systems around the world. But in the long run, the new research suggests that a world dominated by Omicron may experience fewer hospitalizations and deaths than a world where Delta continues to rage.

“Omicron is likely to knock out the Delta,” said Alex Sigal, virologist at the African Institute for Health Research in Durban, South Africa, who led the new study. “Maybe kicking out the Delta is actually a good thing and we’re looking at something that we can live with more easily and that will bother us less than previous variants.”

Published the institute’s new study Web site On Monday. It has not yet been published in a scientific journal.

Independent scientists said the results of the South African experiment were solid, though preliminary. Carl Pearson, an epidemiologist at the London School of Hygiene & Tropical Medicine, said the findings are consistent with what is currently happening in the UK.

“The Omicron is coming and going fast, and the Delta trend is going down,” he said.

Nathan Grubaugh, an epidemiologist at the Yale School of Public Health, said he observed the same pattern in Connecticut. “We’re seeing Omicron increase exponentially while delta cases are falling,” he said. “This shows me that Omicron outperforms Delta for susceptible individuals, then makes them less susceptible to Delta and reduces Delta cases.”

When people started getting infected with coronavirus two years ago, they produced antibodies and immune cells that could protect against it. As a result, it was very rare for a person to become reinfected in the months that followed.

But from the end of 2020, new coronavirus variants have emerged. Some, like Alpha, had mutations that allowed them to spread rapidly. Others, such as Beta, have had adaptations that allow them to escape antibodies – whether they are produced during a previous infection or in response to a Covid-19 vaccine.

Delta, which came to prominence in the summer of 2021, had mutations that gave it both a superior ability to spread and a moderate ability to evade antibodies. Vaccines still continued to be effective against Delta, but not as much as before in the pandemic.

When Omicron emerged in November, it spread even faster than Delta. The researchers suspected it had two sources for its speed. Somehow he was able to transmit it quickly – perhaps by copying a large number or spread more easily from one person to another. Omicron has also been able to infect people who have been vaccinated and those who have fallen ill with previous variants.

In a study earlier this month, Dr. Sigal’s team and a number of other research groups, approved Omicron’s ability to fend off antibodies from vaccines and earlier variants. To do this, they analyzed blood from people who had been vaccinated or recovered from Covid and mixed it with different variants.

Antibodies so strong against Delta and other variants have repeatedly done a poor job against Omicron. This helped explain why so many vaccinated and previously infected people had Omicron seizures, albeit milder than Delta infections.

In his new work, Dr. Sigal and colleagues did the same experiment, but this time on people recovering from Omicron infections. Although South Africa is experiencing a large increase in Omicron cases, Dr. Sigal and colleagues have only been able to study 13 patients so far.

“It was very difficult because of the holiday period,” he said. “Nobody really wants to stick around and be part of a study.”

Seven of the patients were vaccinated and six were unvaccinated. The scientists did not determine which volunteers were previously infected with other variants of Covid. But given that the vast majority of South Africans had Covid before Omicron, it is likely that most of the volunteers were not infected with Omicron for the first time.

Not surprisingly, the researchers found that the patients’ blood contained potent high levels of antibodies to Omicron. However, these antibodies have also proven to be effective against Delta.

This was particularly surprising because the team’s work earlier this month showed that the opposite was not true: antibodies produced after Delta infection offered little protection against Omicron.

As Omicron runs from country to country, Dr. Sigal predicted that it would leave the people immune not only to himself, but to Delta as well. This means that people infected with Delta will have fewer opportunities to pass the virus on to others. It will also easily infect people recovering from Omicron Delta. That competitive advantage could spell doom for Delta.

Of course, that’s a lot of speculation about the future health of billions of people based on just 13 volunteers. Moreover, Dr. Sigal can’t say exactly what the Omicron’s benefit against Delta is. It is possible that the antibodies it produces may also act more broadly against other variants.

Alternatively, it is possible that Omicron infections simply evoke in the volunteers the existing immunity conferred by vaccines or previous infections. If that’s true, we’ll see what happens to the unvaccinated people infected with Omicron for the first time – a fate millions of Americans may suffer in the coming weeks.

Even if Omicron destroys Delta, that doesn’t mean Omicron will prevail for generations. Once humans have become immune to Omicron, natural selection may favor mutations that produce a new variant that can evade that immunity.

Dr. Pearson said that he can predict three different futures depending on the characteristics of the coronavirus.

In one, Covid mimics the flu, with one seasonal variant outpacing the previous one each year.

In a second, Covid mimics dengue fever, with several variants escaping different antibodies, causing people to get sick from one of them every few years.

The third possibility is the most desirable: A variant acquires and becomes an easily avoidable pathogen. However, Dr. Pearson sees this as the least likely scenario.

“I bet we can rule out that it’s headed for a place where it locks onto a single strain that’s a long-term immunizer and becomes a childhood infection like measles,” he said. “But it’s still possible.”