The latest Omicron quirk: "Asymptomatic carriage"

AP Photo/Susan Walsh

Most of the solid data we’ve been given regarding the Omicron variant (as opposed to the constantly shifting goalposts of the CDC and NIH) has come out of South Africa. That makes sense, since that’s where researchers first identified Omicron and they’ve had a large population sample to work with. The South African doctors have stuck with their original assessment of Omicron producing considerably milder symptoms in patients, with significantly reduced rates of hospitalizations or deaths. But the latest pair of studies from that region that were just released this week offer some new details which are either worrisome or – just possibly – encouraging, depending on how you choose to interpret it. The bottom line is that there is almost certainly a lot more Omicron going around than even the latest testing results indicate and the reason for that is that Omicron infections are frequently characterized as producing no noticeable symptoms. It’s a category they are referring to as “asymptomatic carriage.” (Reuters)

Preliminary findings from two South African clinical trials suggest the Omicron coronavirus variant has a much higher rate of “asymptomatic carriage” than earlier variants, which could explain why it has spread so rapidly across the globe.

The studies – one of which was carried out when Omicron infections were surging in South Africa last month and another which resampled participants around the same time – found a far greater number of people tested positive for the coronavirus but were not showing symptoms compared to previous trials.

“The Sisonke study included 577 subjects previously vaccinated, … with results suggesting a high carriage rate even in those known to be vaccinated,” the researchers said.

So we now have yet another medical term we’ll have to get used to hearing, but the layman’s definition is pretty simple. There are people contracting this variant who don’t even notice that they are sick. It’s not a small number, either. Compared to previous versions of the virus, the number of asymptomatic people with Omicron has skyrocketed. The studies discovered this because they weren’t originally looking for COVID patients. They were studying people with HIV and other diseases.

In one of the studies, 31% of the participants who were HIV positive also tested positive for the Omicron variant of COVID. In the pre-Omicron series of this study, only 1% to 2.4% of the asymptomatic people tested positive for either the Beta or Delta variants. That’s absolutely a very large increase.

In a second trial using the J&J vaccine, 16% of the asymptomatic patients tested positive for Omicron. That group had previously produced a rate of 2.6%. So as I said, this isn’t a slight bump. It’s at least five times more common and as much as ten times more common in some groups.

That brings us to the “good news, bad news” part of the story. We already know that Omicron is on the loose in the United States and it’s showing up all over the place. But until the Biden administration gets this test kit supply situation figured out, most of the people who are being tested are the ones that show up at hospitals and other medical facilities with any sort of medical complaint or injury. According to these new numbers, there could be a very significant percentage of the population who are walking around with Omicron right now without realizing it and could potentially be spreading it to others.

But there’s a second side to that coin as well. This asymptomatic carriage could mean that there are also entire herds of people (pardon the term) who have already had Omicron without realizing it and come out the other side with their own form of immunity. That’s probably particularly true of the vaccinated, who are still coming down with the virus at pretty much the same rate as everyone else. We’ve been told repeatedly that a combination of both a vaccine and your own naturally developed antibodies provides a “superman” level of protection. But even the unvaccinated may be benefitting from this.

We’ll need to wait until some comprehensive studies are completed in America along the same lines as the South African testing before we know for sure. But Omicron may turn out to be a gift in disguise that gets us closer to herd immunity without having to force the vaccination rates higher.