Covid: Little Respite, Another Omicron Version is Knocking the Doors

Manas Dasgupta

NEW DELHI, Feb 1: Even as the new daily cases in India continued to dip during the last few days, fresh studies on newer variants in different countries provide little solace to the pandemic-stricken world. The new studies are emerging that suggest the latest version of the highly-infectious omicron variant is transmitting even faster than the original, and mild cases of the first may not offer much protection against future infections.

The findings cast doubt on hopes that the scientists initially fostered that the wave of omicron that’s sweeping the world may help hasten the end of the pandemic. The prediction bred global rise in calls for governments to treat Covid-19 as endemic like influenza as people grow tired of pandemic restrictions, vaccines become more accessible and deaths remain relatively low.

While BA.1, the original Omicron variant, is still the most dominant type worldwide, recent trends suggest BA.2 is increasing in some countries including India, South Africa, the UK and Denmark, the World Health Organization said last month.

Over the past several weeks, omicron BA.2 has begun to surprise scientists. And it’s starting to look like it can, in some countries, outcompete its sibling omicron BA.1 — and, really, any other variants.

Back in December, omicron BA.1 caused a massive surge in cases in Denmark, similar to the surge in the United States. But then, just as cases began to decline, BA.2 started spreading very rapidly in Denmark. After only a few weeks, BA.2 took over the outbreak there and has lengthened Denmark’s surge. Denmark’s cases are climbing steeply, with more than 40,000 recorded each day. Since the second week in January, BA.2 has caused more than 50% of those cases, the Statens Serum Institut in Copenhagen said.

Just as the omicron surge starts to recede in parts of the U.S., scientists have their eye on another coronavirus variant spreading rapidly in parts of Asia and Europe. It’s officially called “omicron BA.2,” and this week scientists detected cases of it in several U.S. states, including California, Texas and Washington.

The production of neutralizing antibodies during an omicron infection appears related to the severity of the illness, according to one report from researchers at the University of California, San Francisco. The milder form of most omicron cases in vaccinated people may leave those who recover from them still vulnerable to existing virus and future variants that emerge, the researchers said. The protection from a natural infection was about one-third that obtained through a booster shot, the study found.

“Our results suggest that omicron-induced immunity may not be sufficient to prevent infection from another, more pathogenic variant, should it emerge in the future,” the researchers said. “They also highlight the continued importance of vaccine boosters in enhancing immunity, as breakthrough infection alone may not be reliable” in protecting against repeat infections or future illness from new strains, they said.

The second study found a second-generation form of omicron appears even more transmissible than the original. It showed 39% of people infected with the BA.2 sub-variant were likely to infect others in their households, compared with 29% of those who were carrying the original version. The study analyzed data gathered from 8,541 households in December and January in Denmark.

The risk of infection with either type was higher in those who were unvaccinated, underlining a positive effect of vaccination, the investigators said. The findings bolster work from UK health authorities released last week that found the omicron sub-variant appears even more contagious than the original fast-spreading strain. That analysis also showed booster shots remain an effective shield, the UK Health Security Agency said.

The omicron sub-variant appears to be more contagious but data so far doesn’t show it’s more dangerous or that it evades protection from vaccines, said Scott Gottlieb, the former commissioner of the US Food and Drug Administration. At worst, the strain could slow down the decline in omicron infections in the US, he said.

“It could be that BA.2 does have some small advantage,” an epidemiologist at the University of Bern who has been tracking variants all around the world throughout the pandemic said. “BA.2 might well be, like, 1% to 3% more transmissible, or something like that.” So the big question now is, will that small difference be enough for this variant to lengthen the ongoing surge in the U.S., as it has in Denmark?

Back in November, when scientists in South Africa and Botswana discovered omicron, they didn’t find just one version. They found three, called BA.1, BA.2 and BA.3 by the Phylogenetic Assignment of Named Global Outbreak Lineages at the University of Edinburgh. The first one, BA.1, took off rapidly and spread around the world and initially it looked like BA.2 and BA.3 were weaker and less able to keep up with BA.1. “We thought, ‘OK, BA.2 is just not as fit as its sibling BA.1, and it will kind of peter out,’ ” researchers said. But that’s not what happened — not at all.

Omicron BA.2 is also growing exponentially in England and Germany where it’s causing at least 5% of cases in both places. Scientists are concerned it could lengthen surges in those locations as well as possibly in the United States.

Together, this data indicates that BA.2 is not BA.1’s weaker sibling, but rather that BA.2 is quite strong and possibly more contagious.

Many studies have shown that infections with omicron BA.1 carry a reduced risk of severe disease compared with the delta variant of the coronavirus. Preliminary evidence from Denmark suggests this will also be the case with omicron BA.2, scientists said. “Scientists have found that there was no increased risk in going to the hospital if you have BA.2 compared to if you have BA.1,” researchers said. “That could change, but that’s what we know so far.”

And there’s cautious optimism about inoculations. Preliminary data from the U.K. government show that a third shot of a COVID-19 vaccine protects against an infection of BA.2 just as well as it does against BA.1. In both cases, it reduces the risk of a symptomatic infection by about 60% to 70%. In addition, there are many similarities between BA.1’s and BA.2’s spike proteins — the part of the virus that many antibodies target. The scientists expect the vaccines would likely provide superb protection against severe disease.

“I have no guarantee that you won’t get infected or possibly reinfected [if you’ve already had COVID-19], meaning that you might have the sniffles or feel like you have another cold, but I feel very, very confident that you would be protected from serious disease in the general population,” an expert said.