Just when we thought we were seeing the light at the end of the pandemic tunnel, a new variant — named Omicron — emerged. Although it’s been discovered relatively recently, the variant already has the whole world on alert. Although we’ve only had a few studies on it, we already know quite a bit about it.

It’s already everywhere

The Omicron variant has already been discovered in at least 89 countries, according to the World Health Organization (WHO). In many of these countries, there is already community spread. In other words, it’s not going to stop or be squashed anytime soon.

In other words, travel bans and travel restrictions won’t stop the virus’ spreading; at most, they can delay its arrival. The WHO added that such measures are not just unproductive, but also costly:

“Blanket travel bans will not prevent the international spread, and they place a heavy burden on lives and livelihoods. In addition, they can adversely impact global health efforts during a pandemic by disincentivizing countries to report and share epidemiological and sequencing data,” the organization said in a statement on December 1.

Simply put, Omicron is out of the box and spreading all around the world.

It’s much more contagious than Delta

The first cause of concern when it comes to Omicron is that it appears to be much more contagious than the Delta variant — which itself was much more contagious than the original variant.

In areas with local spread, the number of Omicron cases seems to be doubling every 1.5-3 days, an enormous growth rate. This means that if you start with 1,000 cases today, you’ll end up with over 1 million cases a month later. This is clearly visible in England (where the strain is already becoming dominant), and is apparent everywhere the virus has emerged.

It’s hard to say just how contagious this variant is, but for now, there is convincing evidence that it is contagious enough to become the dominant strain, like Delta became the dominant one before it.

It has many mutations that make it different

Unlike previous strains, which exhibited only a few mutations, Omicron has a whopping 57 mutations. Not all of these are dangerous (there’s a good chance some of these don’t even do anything), but with so many mutations, there’s still a great deal of uncertainty when it comes to what this strain is capable of.

Speaking on NPR’s “Weekend Edition“, National Institutes of Health director Francis Collins commented:

“Nobody expected Omicron — this one was really a curveball, a variant that has 57 different mutations in it that makes it almost like we’re starting over with a different virus than where we began.”

In particular, over 30 of these mutations affect the viral spike protein — the part which the virus uses to attach itself to health. Changes to these can make the virus more contagious and more capable of evading vaccines (though this is not guaranteed). For instance, a preprint study found that Omicron is three times more likely to reinfect those previously infected with other strains.

It has some ability to evade vaccines — but it’s not clear how much

Without a booster shot, existing vaccines seem to not offer too much protection against the variant. For instance, one study found that the vaccines produced by Johnson & Johnson, Russia’s Sputnik vaccine, and China’s Sinopharm provide little to no protection against the virus. This is still preliminary data and these vaccines could still protect against severe cases and hospitalizations, but there are clear signs of vaccine resistance. The AstraZeneca vaccine yielded similar results.

The mRNA vaccines, in the two-dose regimen, are only somewhat better. The Pfizer vaccine was just 33% effective against infection — although it was 70% successful against severe disease that required hospitalization. Moderna was largely in the same boat as Pfizer.

Again, these are still preliminary studies and focus on antibody levels — real immunity is also dependent on other parameters, such as T cells, but major observational studies have not been published yet.

The booster dose appears to grant good protection against Omicron

The first piece of good news is that boosters appear to be highly effective against Omicron.

Although two doses of Pfizer have little neutralizing ability against the virus, boosters seem to perform much better. In a company study, the booster (which was previously mostly a way of extending immunity rather than granting increased immunity) makes the vaccine effective against Omicron.

“Although two doses of the vaccine may still offer protection against severe disease caused by the Omicron strain, it’s clear from these preliminary data that protection is improved with a third dose of our vaccine,” said Albert Bourla, CEO, Pfizer. “Ensuring as many people as possible are fully vaccinated with the first two dose series and a booster remains the best course of action to prevent the spread of COVID-19.”

“Our preliminary, first dataset indicates that a third dose could still offer a sufficient level of protection from disease of any severity caused by the Omicron variant,” said Ugur Sahin, CEO and Co-Founder of BioNTech. “Broad vaccination and booster campaigns around the world could help us to better protect people everywhere and to get through the winter season. We continue to work on an adapted vaccine which, we believe, will help to induce a high level of protection against Omicron-induced COVID-19 disease as well as a prolonged protection compared to the current vaccine.”

Yet again, Moderna is in the same boat. In a recent study, the company found that its booster is also effective at fighting Omicron. The currently authorized 50 µg booster of mRNA-1273 increased neutralizing antibody levels against Omicron approximately 37-fold compared to pre-booster level.

It’s probably not more severe than Delta

The second bit of good news is that based on what we’ve seen so far, Omicron won’t cause more severe disease than Delta. Based on an app where the British public self-reports symptoms, the main symptoms of Omicron are runny nose, headache, fatigue (either mild or severe), sneezing, and sore throat. Notably, there is no fever, coughing, or loss of smell and taste among the most common symptoms, based on this study at least.

But there’s a catch: the adult population of the UK is 90% vaccinated (and over half of the over 18s already have a booster shot). So Omicron seems milder — but on a vaccinated population.

There are speculative reports that Omicron may be indeed milder, but this is still unclear and optimistic. A British paper, which is yet to be peer reviewed, found no evidence of a difference in the severity of symptoms or hospitalisations when compared with Delta. For now, we don’t know yet, and there’s not much reason to be optimistic just yet.

We’re likely headed for another big wave. The best thing to do against Omicron at the moment is to get a booster

We’re headed for a long winter. In a recent intervention, Dr. Anthony Fauci expressed his concerns about how we will face Omicron.

“We are going to see a significant stress in some regions of the country on the hospital system, particularly in those areas where you have a low level of vaccination,” he added. “This virus is extraordinary. It has a doubling time of anywhere from two to three days,” adding that the variant is “going to take over. It is going to be a tough few weeks to months, as we get deeper into the winter.”

There’s still much we’ve yet to learn about this variant, but for now at least, the best option we’ve got is to get a booster as quickly as possible. The science is coming in fast, and it’s best to be prepared. Omicron seems very contagious, and with an already fatigued and overworked medical system, things could easily go awry.

Hopefully, we’ll be more prepared for this one.