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 previous variants, 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 were in people who are unvaccinated.
On Friday, the World Health Organization named the newest variant of concern, omicron. After scientists in South Africa identified the variant 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. This week, President Joe Biden issued a travel ban on eight countries in southern Africa over omicron variant concerns. Omicron has been found in many other countries, including Scotland, Portugal, Canada and the United Kingdom.
On Monday, the Netherlands government announced that it had detected omicron in COVID-19 samples taken prior to South Africa’s alert to the WHO, suggesting that omicron has had a footing in Europe for longer than scientists thought.
Right now, scientists think that omicron is likely to be as contagious as delta or more, and that 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.
As scientists learn more by the hour, here’s what we know about delta versus the omicron variant.
Is omicron worse than delta?
Right now, it’s too early to tell. Omicron has some similar mutations in its spike protein to the delta variant, according to 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 or not that means anything remains to be seen.
“What all those changes in the aggregate are going to do for the things that matter for this virus, we don’t really know yet,” Robert Garry, a virologist at Tulane University, told CNN.
What is a mutation or variant?
The coronavirus enters our cells using its “corona,” or layer of protein spikes, then makes copies of itself in our bodies, where inevitably there are some errors or mutations, as explained by Yale Medicine. Sometimes those mutations in the virus are harmless, but other times – like in the case of the delta and omicron variants – they make it much easier for the virus to spread from person to person and infect more people.
The more people who are unvaccinated or without immunity from COVID-19, the more opportunities there are for the coronavirus to spread and form concerning variants.
“I think what you’re seeing is just the manifestation of what we’ve been talking about,” Dr. Anthony Fauci, President Joe Biden’s chief medical advisor, told NBC Sunday. “Why it is so important for people to get vaccinated, and for those who are fully vaccinated to get boosted.”
Apart from vaccine hesitancy, many people in countries outside the US don’t have access to a COVID-19 vaccine. According to Our World in Data, 6% of people in low-income countries have received a dose of coronavirus vaccine.
“The emergence of the omicron variant should be a wake-up call to the world that vaccine inequality cannot be allowed to continue,” South Africa’s president, Cyril Ramaphosa, said in an address.
What are the symptoms of omicron vs. delta?
Dr. Angelique Coetzee, a South African doctor who helped discover omicron, told BBC that so far, patients she’s seen with the omicron variant have “extremely mild cases” of COVID-19. Those symptoms included fatigue, headache and a scratchy throat, she said – not the telltale loss of smell or cough associated with earlier COVID-19 infections.
However, the delta variant also changed the way COVID-19 presents. Cough and loss of smell are also less common symptoms of COVID-19 caused by the delta variant compared with earlier variants, per the Baton Rouge General, a Mayo Clinic network. Cold symptoms like a headache and runny nose are now more common symptoms of COVID-19, according to the United Kingdom’s Zoe COVID Study.
In general, it’s too early to make a claim that omicron has better or worse symptoms than delta. Although anecdotal evidence shows that confirmed cases of COVID-19 caused by omicron have caused mild symptoms, most of those people have been younger, according to South Africa’s health department. Younger adults and children are generally less likely to experience severe COVID-19 than older adults.