Why are scientists worried about omicron? 5 vital facts about the variant

The United States has joined the club of countries with confirmed cases of the new omicron variant of SARS-CoV-2, the virus that causes Covid-19. The first U.S. incidence was announced Wednesday, December 1 in California, just a week after South African scientists sounded the alarm over this mutated form of the coronavirus. Aside from genetic sequence data and the confirmed cases across the globe, there is really very little scientists can definitively say about omicron — but there are clues.

What is omicron?

Omicron is the latest coronavirus variant on the World Health Organization’s list of variants of concern — alpha, beta, gamma, and delta are the other four. It has a laundry list of mutations never seen before, including 32 on its spike protein. The spike protein is the key to a cell’s door — it lets the virus bind to a cell, enter the cell, and then hijack the cell to make it a virus-producing factory. It’s also the part of the virus Covid-19 vaccines teach our body’s immune system to recognize and attack.

Infectious disease expert Anthony Fauci guessed it would take a week or more before scientists have a clearer idea of what the variant does and what it means for public health — that was on CNN on Monday, November 29.

In the meantime, here’s some more of what we do and don’t know about omicron.

Why is omicron worrying?

In a word: Mutations. Omicron has more than 50 mutations differentiating it from the original strain of SARS-CoV-2. Viruses mutate, so the mutations aren’t themselves odd but often, the more transmissible a virus becomes, the more mutations they develop.

Scientists know two essential pieces of information already about omicron’s mutations:

1. Some of omicron’s mutations are the same as other variants of the coronavirus, most notably delta. But 26 of omicron’s mutations are completely original to this variant — we haven’t seen them before and we don’t know what they do.
2. Many of omicron’s mutations are on the spike protein. The more mutations to the spike protein, the harder it can be for the immune system to neutralize the virus.

Think of it like baking a cake. Unknown mutations are like adding ingredients without labels, blindfolded — maybe what you just added was a cup of sugar, maybe it was salt. Maybe you add two things that balance each other out. Maybe they compound each other, making the cake ultimately taste even worse. You won’t know until you taste it.

What are the most concerning omicron mutations?

There are three mutation questions that matter to public health:

1. Does the mutation cause a more severe disease?
2. Does the mutation make the virus more transmissible?
3. Will vaccines protect against the variant?

Scientists don’t know the answers to any of these questions regarding omicron, but there are clues.

• Most cases of Covid-19 are mild, so it may be a few weeks before we have a sense of if it causes more severe disease.
• In South Africa, cases of omicron appear to be rising faster than they did with the delta variant, but there hasn’t been an obvious change in the rate of hospitalization. That may be because it’s too soon to know, or it could be because omicron doesn’t cause more severe disease. We just have to wait and see.
• Much as we like to think of vaccines as all or nothing — the protection they offer exists on a spectrum. Breakthrough infections are possible with some mutations and immunity wanes over time. With the four other VOCs, we know that if breakthrough infections occur, vaccines still offer protection from hospitalization or death for the vast majority of fully vaccinated individuals.

Omicron does have more mutations on the spike protein than anything we’ve seen before, which means we shouldn’t assume the old rules apply to this variant. Crucially, however, we also shouldn’t assume the old rules don’t apply to omicron, either.

For example, both the mu and beta variants initially caused a great deal of concern that they’d be able to evade vaccines. But they weren’t nearly as transmissible as the delta variant, so ultimately, they didn’t make much of an impact.

Do travel bans work?

Despite how much we don’t know about omicron and a lack of scientific evidence to suggest travel bans slow the virus, countries including the United States have restricted flights to and from South Africa (Israel went as far as to ban any foreigners from entering the country). Omicron has been detected in more than 20 countries.

We live in a very small world — international travel happens all the time. By the time a new variant is identified, it’s in more countries beyond where it was first identified. For his part, Fauci suggested two days before the first confirmed U.S. case was found that the U.S.’s travel ban on some African countries could buy public health officials a week to prepare for the new variant.

“There is very little utility of these kinds of bans...Unfortunately, from what we know about the epidemiology of SARS-CoV-2 and the epidemiology of this variant, the horse has probably left the barn,” Saad Omer, director of the Yale Institute of Global Health, told NPR Monday.

When will we know more about omicron?

While it’s frustrating to know about a variant like omicron — and how many unusual mutations it has — without knowing the full scope of how it will behave and what it means for public health, the simple fact is that’s how science works. It will take two to three weeks to understand the scope of the mutations and how they might affect public health measures like masking.

But there are things you can do in the meantime. First and foremost, if you haven’t been vaccinated, do that now. If it’s been more than six months since you’ve gotten the full first round of shots (whether that’s two mRNA jabs from Pfizer-BioNTech and Moderna or one jab from Johnson and Johnson), and you live in the U.S., get boosted. While the current mRNA Covid-19 vaccines work by targeting the spike protein, our bodies produce complex immune responses that still offer some protection from hospitalization and death.

While there’s much we don’t know about omicron, the fundamental practices we take to reduce our risk of contracting Covid-19 remain the same.