On Jan 3, Monday, the US reported over a million cases of COVID-19. Yes, 1 million. That is a record by a staggering margin—almost twice the previous record. In fact, the previous record for per-day cases of COVID-19 was also held by the US, reporting 590,000 cases just last week—also nearly double the count the previous week.
As the Omicron variant of the virus sweeps the world, a surge in cases has been reported across every continent: the US and UK, South Africa, France, and now India. Recognized by the World Health Organization (WHO) as a Variant of Concern (VOC) on November 26, Omicron is soon expected to surpass Delta as the world’s most dominant strain.
However, while Omicron seems more infectious than Delta, does it also cause more severe symptoms? In other words, is Omicron more lethal than Delta? What about vaccines? Are two doses of a COVID-19 vaccine enough to protect against the new strain? Or will we need a third—a booster?
The Omicron variant has raised so many new questions. Here we will answer some of the biggest.
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What is a variant?
A variant is a mutated or evolved virus.
The virus responsible for COVID-19, termed SARS-CoV-2, is a coronavirus. The term corona refers to the ‘crown’ covering its outermost layer—spikes of protein that cleave our cells, allowing the virus to enter them. Once in, the virus reprograms our cells to produce more of it, hijacking their resources to achieve this.
The thing is, the replication is not perfect. The result is a mutated virus. Most mutations are harmless. In fact, scientists have cataloged over 10,000 mutations of SARS-CoV-2 (Nature). However, often, a mutation may alter the virus in a way that makes it easier to spread or more deadly. (Or, in the case of Delta, both.)
WHO labels such variants as variants of concern. Till now, we have identified five: Alpha, Beta, Gamma, Delta, and Omicron.
Read more: #COVID19: Will We Need a Third Dose of the Vaccine?
Omicron vs. Delta: Is Omicron worse than Delta?
The Delta variant was first discovered in late 2020 in India. In less than a year, it spread rapidly to become the most dominant strain globally. In fact, its high transmissibility was its defining feature; it is one of the most transmissible respiratory viruses we have discovered.
Here is the kicker: Omicron is the most transmissible respiratory virus we have discovered. The virus has a generation time of 4 days and spreads to an average of 6 people in that period. What that means is, it takes 4 days, on average, for 6 people to become infectious. However, those 6 people can spread the virus to 36 more in the next 4 days, such that in 12 days, the virus would end up infecting, 36 times 6, 216 people! A study by Hong Kong University found that Omicron, over the first 24 hours, multiplied 70 times faster than the Delta variant.
But while the Omicron variant is the most explosive in terms of transmissibility, it is not in terms of severity. At least, that is what most of the preliminary data suggests.
The Hong Kong University study found that the virus replicates rapidly in the bronchus, not the lungs, making it highly infectious, but not deadly. Data collected from hospitals in South Africa, where the variant was first discovered, indicates at shorter stays, fewer ICU admissions, and lesser need for supplemental oxygen.
The South African analysis has shown that hospitalizations are down by as much as 80%. As for the US, hospitalizations are reportedly down by 43% compared to the surge last winter, while the death rate is down by nearly 50% (CDC). As Biden’s chief medical advisor, Dr. Anthony Fauci, remarked, all “indications point to lesser severity of Omicron versus Delta.”
Read more: The Impact of Pandemics Like Corona Virus on Healthcare Workers
Do I need a booster shot?
All indications may point to lesser severity, but Fauci has urged us to keep up our guards and warned against complacency, lest we overwhelm hospitals. Do not forget that when hospitals help treat COVID-19, it comes at the cost of not helping treat other conditions.
While masks and social distancing reduce the likelihood of contracting the infection, the best protection remains to be a vaccine. However, the recent surge has seen even the fully vaccinated diagnosed with COVID-19. Are the vaccines then ineffective against the Omicron variant?
Not really. Yes, reinfections seem widespread, but protection against severe infection, natural or vaccine-induced, seems not that terribly reduced—to about 20%, according to a study by London’s Imperial College. In fact, authors of the South African and North American analyses mentioned above have added that the reason why hospitalizations could be low is that those who tested positive were vaccinated.
Even though protection seems reduced, it is still much higher than it is without being vaccinated. According to CDC estimates, those above 65 and vaccinated are 6 times less likely to be hospitalized when infected than the unvaccinated. For those between 18 and 49, the likelihood reduces to 2 times—still quite low. Now, a 20-30% reduction on those odds should seem bad, but not too worrisome.
And to make up for the reduction, experts suggest that we get a booster shot. The study by Imperial College, for example, found that a booster could boost immunity to 55-80%. The infection caused by the Omicron variant has been described as mild. But the severity could be even milder if we get another shot.
Over 200 million have been vaccinated in the US, of which over 65 million have even received a booster. But that is just one part of the world. The odds are not too worrisome for us, but they are for the underprivileged. Believe it or not, just over 7% of people living in low-income nations have received a dose (Our World in Data). That is one dose. Not even two. And here we are talking about a third.
