Omicron in the US: How the new COVID variant compares to delta

With a virus as contagious as the coronavirus that causes COVID-19, any new variants that are even more transmissible than the original can cloud the path to recovery from a global pandemic. In July, the delta variant, which scientists believe is twice as contagious as earlier ones, became the dominant variant in the US and quickly resulted in a spike of COVID-19 cases and hospitalizations. The vast majority of hospitalizations and deaths have been in people who are unvaccinated. On Nov. 26, the World Health Organization named omicron the newest variant of concern.

As of Sunday, 17 US states and counting have reported cases of omicron, or about a third of the country.

“This news is concerning, but it is not a surprise. We know that this virus is highly infectious and moves quickly throughout the world,” Minnesota Gov. Tim Waltz said in a news release from the state’s health department after a person from the Minneapolis area, who had attended the Anime NYC convention from Nov. 19 to 21, tested positive.

After scientists in South Africa identified omicron following a new spike in cases, researchers around the globe started the race to find out exactly how contagious it is and whether it’ll decrease the effectiveness of the COVID-19 vaccines. Last week, President Joe Biden issued a travel ban on eight countries in southern Africa over omicron variant concerns. Omicron has since been detected in at least 45 countries around the world.

Right now, scientists think that omicron is likely to be at least as contagious as delta and that the level of contagiousness will strain health care systems if left unchecked. But they’re also confident vaccines will continue to be protective against severe disease, and the same public health measures we’ve been using to curb COVID-19 the last two years will also be effective against omicron. According to Dec. 5 data from the US Centers for Disease Control and Prevention, 75.5% of Americans ages 5 and older have received at least one COVID-19 shot.

On Friday, CDC Director Dr. Rochelle Walensky told Good Morning America that there were about 90,000 new cases of COVID-19 in the US every day, and that “and about 99.9% of them continue to be delta.” As scientists work to uncover omicron, here’s how the two variants compare right now.

Is omicron worse than delta (or vice versa)?

It’s too early to tell for sure, but early signals of the severity of omicron are “encouraging,” Dr. Anthony Fauci, President Biden’s chief medical adviser, told CNN — that is, there aren’t safety signals right now that show omicron leads to more severe COVID-19. In terms of how contagious the two variants are: “Clearly, in South Africa, omicron has a transmission advantage,” Fauci said, noting that we need to be “careful” about drawing too many conclusions before there’s more data, which might take a couple weeks. (There is the optimistic view that omicron outcompetes delta as the dominant variant but is also less deadly, which would change the pandemic for the better. But again, it’s too soon to make that distinction.)

Omicron has some similar mutations in its spike protein to the delta variant, according to the Republic of South Africa’s Department of Health, as well as the alpha, gamma and beta variants — all classified as variants of concern by the WHO. This means omicron will also be very transmissible, likely enabling the virus to more easily get around someone’s antibodies, lowering the vaccine’s efficacy against symptomatic disease (as in the delta variant’s case, scientists expect the vaccines to remain protective against severe COVID-19). Scientists from South Africa also believe omicron may lead to more cases of reinfection in people who’ve already had COVID-19.

Omicron has more mutations on its spike protein than the delta variant does, but whether that means anything remains to be seen…Read more>>