What happens to previous COVID-19 variants when a new one becomes dominant? - Market News
Home » What happens to previous COVID-19 variants when a new one becomes dominant?
Covid-19

What happens to previous COVID-19 variants when a new one becomes dominant?

What happens to previous COVID-19 variants when a new one becomes dominant?

(NEXSTAR) – Just when it feels like there’s some positive news in the fight against COVID-19, a new variant rears its ugly head, driving up the number of cases and hospitalizations. But does that mean the previous variant is no longer a concern?

Well, maybe — but not necessarily, according to experts.

The ongoing COVID-19 health crisis, first declared a global pandemic by the World Health Organization in March 2020, started after the discovery of SARS-CoV-2, a new type of coronavirus. As the months went on, new variants started popping up, the most concerning of which were alpha, beta, and delta. And recently, the omicron variant has become dominant in the US, surpassing delta within just a few months of the first cases detected.

“Omicron just pushed delta aside, just like delta pushed everything else aside,” Dr. Davidson Hamer, a professor of Global Health and Medicine at Boston University’s Schools of Public Health and Medicine, told Nexstar.

However, Hamer acknowledges that earlier variants of concern (VOC), such as alpha, beta, or gamma, may still be circulating in places where “sequencing is not routine.” But in the US, where genome sequencing is more common, variants other than delta or omicron are hardly detected. In fact, the CDC’s latest update on variant ratios in the US indicates that earlier variants are responsible for: 0% of current cases.

Should we stop sweating the previous variants?

“We are still concerned about the previous one in the short or medium term,” warns Dr. Jorge Luis Salinas, a hospital epidemiologist at Stanford University School of Medicine and a co-medical director at Stanford Healthcare. “It’s possible they come back or in a derivative form.”

As Salinas explains, the variants that cause public health concerns have “evolutionary advantages” over the previous ones, perhaps resulting in increased transmissibility, more serious diseases or the ability to evade vaccine protections.

“It is more likely that new variants will arise, which have even more mutations, which allow the virus to spread better,” says Hamer.

“Usually it’s kind of an old species that evolves, or evolves further, but it never really goes back to where it came from.”