uk apple-1639991030462
Shoppers, some wearing face coverings to combat the spread of Covid-19, walk past stalls and shops in the Apple Market in Covent Garden on the last Saturday for shopping before Christmas, in central London on December 18, 2021. Image Credit: AFP

Highlights

  • WHO advises caution: “Do not underestimate Omicron”
  • Experts say it’s not about severity, but about high infection rate.
  • High velocity of infections and reinfection could tigger higher hospitalisations, and severe cases.
  • Studies show booster shots from current vaccines do help curb severe Omicron.

The world is facing a huge spike in COVID-19 cases, especially where Omicron is detected. The latest known SARS-COV-2 mutation — labelled a “variant of concern” less than a month ago (November 26, 2021) after cases were first detected in southern Africa — is now confirmed in more than 77 countries. It's likely to have reached more countries than is currently known, say experts.

Will Omicron eventually dominate? It’s too early to say, says Dr Maria van Kerkhove, World Health Organisation's technical lead for COVID-19. She cites data, however, that mutations identified in Omicron confer it with greater transmissibility.

Key updates based on what experts recently said about Omicron: CDC information is updated as of December 19, 2021, while the WHO information is updated as of December 17, 2021.

Is Omicron really more infectious?

Omicron is a fast-moving situation, with cases doubling at a faster rate than other previous variants and able to infect the vaccinated, according to the WHO. Moreover, Tulio de Oliveira, a scientist at Centre for Epidemic Response & innovation in South Africa and part of the team that first sequenced Omicron (and told the world about it), estimates in a recent study that Omicron had a growth advantage of “0.24 per day over Delta”, based on data from Gauteng, South Africa. "This corresponds to a 5.4-fold weekly increase in cases compared to Delta.”

In the runup to Christmas holidays, Omicron has demonstrated a rapid growth in cases in Europe. In Norway, health authorities warned that Omicron could infect up to 300,000 people a day — compared with the previous peak of about 1,000 cases. In the Netherlands, the “snap lockdown” is the biggest news. Meanwhile, Israel now bans travel from the US over Omicron concerns.

The US CDC, America’s top health protection agency, also warned: “The Omicron variant likely will spread more easily than the original SARS-CoV-2 virus and how easily Omicron spreads compared to Delta remains unknown. CDC expects that anyone with Omicron infection can spread the virus to others, even if they are vaccinated or don't have symptoms."

Harvard epidemiologist Dr. Eric Feigl-Ding stated: “Comparing Omicron in South Africa epicenter versus its first wave in 2020 (~Wuhan 1.0 strain), we see Omicron has higher hospitalizations, similar ICU rate, and higher #COVID19 deaths than the 1st wave.”

30 AMINO ACID SUBSTITUTIONS
30 AMINO ACID SUBSTITUTIONS: Omicron’s spike protein has at least 30 amino acid substitutions, 3 small deletions, and one small insertion, says the US CDC. The CDC has highlighted four key mutations that may aid transmission: N501Y, H655Y, N679K, and P681H, the last of which has also been found in the Alpha variant, while a different mutation at this position (P681R) is found in Delta.

Omicron vs Delta: Which one is less severe?

The Omicron-is-less-severe (or less virulent) hypothesis has no solid scientific basis. As a new variant, there’s uncertainty swirling around its severity yet. Amid the spike in cases, the hoped-for lower Omicron virulence remains a hope, not science. Researchers at the Imperial College London, however, highlighted the increased risk of “reinfection” posed by Omicron and the need for booster shots to combat it.

More data are needed to know if Omicron infections, and especially reinfections and breakthrough infections in people who are fully vaccinated, cause more severe illness or death than infection with other variants…We don’t yet know how easily it spreads, the severity of illness it causes, or how well available vaccines and medications work against it.

- US Centres for Disease Control and Prevention (CDC) update as of December 19, 2021

Meanwhie, the journal Nature (December 17, 2021 report) reported: “As cases spread and countries plan their response, researchers await crucial data on the severity of the disease caused by the coronavirus variant.”

Is there any cause for optimism with Omicron?

There are early signs of “decoupling” between new COVID cases and ICU admissions and deaths in South Africa — while cases are up, deaths are down — as Dr Scott Gotlieb, former Food and Drug Administration commissioner, cited in a tweet on Monday. It was based on a 7-day COVID average numbers from March 2020 to December 17, 2021.

“Whether Omicron is inherently less virulent, whether this hopeful finding is result of baseline immunity in infected, or a combination of both, is still unclear,” Gotlieb said.

Also, there are 2 laboratory studies that show “diminished lung cell infectivity for Omicron compared with Delta”. This, experts say, is a “possible” mechanism for a difference in this variant's intrinsic activity.

While the overall picture for Omicron show indications it may well be less severe than prior strains, it’s also causing more hospitalisations and deaths attributed to it.

Omicron thrives in airways
Image Credit: Seyyed de la Llata, Senior Designer

It's conundrum, at best: Even if Omicron does cause less severe disease, another health expert warned its high infection rate could have “devastating consequences.”

Tim Spector, professor of genetic epidemiology at King’s College London, said: “If numbers skyrocket, it doesn’t matter if the percentage of people being hospitalised or dying remain low—it’s about volume, not percentages. The higher rate of transmission even in the vaccinated could have devastating consequences, and hundreds of people continue to die every week as we head into our second Christmas of this pandemic.”

How many hospitalisations and deaths are attributed to Omicron?

The UK has reported a 10,000 jump in Omicron cases on Saturday. It reported 12 deaths on Monday from Omicron, with 104 currently in hospital with it, according to Deputy Prime Minister Dominic Raab. In the US, COVID-19 cases are surging upward again. US health officials say the Omicron variant is likely to cause “record-high” COVID cases and hospitalisations.

How bad it gets depends how quickly people act, according to mathematical modellers. Still whether the US surge will be followed by an unprecedented level of hospitalisation and death remains uncertain.

If numbers skyrocket, it doesn’t matter if the percentage of people being hospitalised or dying remain low—it’s about volume, not percentages. The higher rate of transmission even in the vaccinated could have devastating consequences, and hundreds of people continue to die every week as we head into our second Christmas of this pandemic.”

- Tim Spector, professor of genetic epidemiology at King’s College London

One model shows that in a worst-case scenario, the new variant could result in 20% more US COVID-19 deaths than last winter (2020-2021).

When was Omicron first reported?

It was only less than a month ago today. On November 24, 2021, a new variant of SARS-CoV-2, B.1.1.529, was reported to the World Health Organisation (WHO). This new variant was first detected in specimens collected on November 11, 2021 in Botswana and on November 14, 2021 in South Africa.

On November 26, 2021, WHO named the B.1.1.529 Omicron and classified it as a Variant of Concern (VOC). On November 30, 2021, the United States designated Omicron as a Variant of Concern, and on December 1, 2021 the first confirmed U.S. case of Omicron was identified.

Scientists, among them genome detectives, are working extra long hours to learn more about Omicron, as a global network of scientists and public health officials, including the WHO, continue to monitor its course.

“In terms of transmissibility, we are seeing a really increased growth rate of Omicron over other variants of concern. These are some of the sharpest increases that we've seen to date. We do know that it has what we call a ‘growth advantage’ over Delta”.

- Dr Maria Van Kerkhove, WHO’s COVID-19 technical lead (December 17, 2021)

Would higher transmissibility lead to more hospitalisations?

“This is a concern that we have,” said WHO’s Maria van Kerkhove. “With more cases, if there's more increased transmissibility, which is what we are seeing, we'll have more cases…More cases mean more hospitalisations and more hospitalisations can put health care systems that are already overburdened into a state where people will not get the appropriate care that they need.”

india health omicron covid
A health worker sets up beds inside a ward being prepared for the omicron coronavirus variant at Civil hospital in Ahmedabad, India, Monday, Dec. 6, 2021. Image Credit: AP

Do current vaccines work against Omicron?

Yes. The WHO said on December 8, 2021 that existing vaccines should work against Omicron. On Friday (December 17, 2021), UK researcher analysing the likely impact that a COVID booster shots will have on Omicron say it could provide around “85% protection" against severe COVID.

An article published in the medical journal BMJ states that Pfizer and BioNTech started developing an Omicron-specific version of their vaccine on November 25, 2021, adding that the first batches could be ready for delivery within 100 days, pending regulatory approval. Moderna is also working on an updated version against the new variant and said it could be finished with testing and ready to file with the regulators by March 2022.

Studies show vaccine prevent worst COVID outcomes, based on lab data showing immune cells put up a strong fight against Omicron, There’s evidence of higher vaccine efficacy, as indicated by “neutralisation titre”, with higher dosage (100 micrograms) of mRNA shot, specifically using current Moderna’s mRNA-1273 jab.

New lab data showing antibody (Ab) neutralisation titres vs Omicron for Moderna vaccine booster — with sera taken from 40 individuals vs a “pseudovirus" — showing an 83-fold increase Ab titres with a 100-μg (micrograms) dose after a month; for the 50 μg dose, there was a 37-fold increase in titres.

What about breakthrough infections?

Breakthough infections, or infections among the vaccinated or those who were previously infected, may still happen.

However, Dr Scott Gotlieb, former Food and Drug Administration commissioner, explained that it does not mean current vaccines don't work. "A properly boosted vaccine does appear to be quite effective in providing meaningful protection. We are going to see breakthrough infections...the premise is the vaccines should and do appear to protect you against severe symptoms," he told CNBC.

WHAT AN ANTIBODY TITRE SHOWS:
This test is carried out to investigate if there is an immune reaction triggered by foreign invaders (antigens) — or vaccine — in the body by determining the presence and level (titre) of antibodies in the blood (also called “seroprevalence”).