Skip to main content
COVID-19: How contagious is Omicron?

COVID-19: How contagious is Omicron?

A new variant of COVID-19 was discovered in late November 2021. Named Omicron (and known scientifically as B.1.1.529), the variant was identified by Dr Angelique Coetzee of the South African Medical Association. We're still in the early stages, and not a lot is known about the Omicron variant just now - new information is coming to light each day. However, we can explore how contagious it could be, and how we can protect ourselves against it.

It’s really important to remember that we are "learning as we go" with Omicron. This Omicron variant was only detected one month ago. The SARS-CoV-2 variant is being studied in real time and data change rapidly.

Continue reading below

What are the symptoms of the new Omicron variant?

Professor Rodney Rohde says that, while this is a new variant for COVID-19, the majority of its symptoms remain similar to what we have all come to recognise. These symptoms include:

However, early data are showing Omicron infections are presenting with fatigue and body aches over more common symptoms like breathlessness or loss of taste and smell.

Upon discovering the variant, Dr Coetzee told BBC that her patients with the Omicron variant presented with extreme tiredness and muscle aches, along with a scratchy throat and dry cough.

The data are also showing that unvaccinated individuals are displaying more of the severe issues connected to the omicron variant.

The World Health Organization (WHO) initially reported that young people infected with the variant had mild illnesses. However, Dr Coetzee warned that we should be more concerned about older people, particularly those who are unvaccinated. Those who have not been double jabbed are more likely to suffer a severe form of the virus. However, the true severity of the Omicron variant will not become apparent until more research has been carried out, with evidence now showing that a booster jab is required to provide maximum protection.

"As a medical laboratory professional who is a specialist in virology, microbiology and molecular diagnostics, I also always like to remind people that you cannot truly be diagnosed with COVID-19 without a confirmatory test. The best and the most accurate remain PCR-based tests," says Professor Rhode.

Is the Omicron variant in other countries?

The WHO has tracked the new variant in at least 50 countries now, and it continues to spread rapidly in South Africa. But the latest epidemiological report from the WHO says that, since the Delta variant remains dominant, particularly in Europe and the USA, it is still too early to draw any conclusions about the global impact of Omicron.

The first confirmed Omicron case in the USA was identified on 1st December, and it is now present in 30 states, including Washington DC, Texas, New York, California and Michigan.

According to The WHO's report, South Africa reported 62,021 cases of Omicron between 29th November-5th December. This was an 111% rise from the previous week. South Africa also had an 82% increase in hospital admissions due to COVID-19 during this week, with 912 admissions compared with 502 the previous week. However, it is not yet known how many of these cases were due to Omicron.

Omicron seems to be spreading rapidly in South Africa despite high rates of past infection with COVID-19. Estimates suggest between 60-80% of the population have previously been infected, and vaccination rates remain low at about 35%.

As of 6th December, all 212 confirmed Omicron cases across 18 European Union countries were classed as asymptomatic or mild.

On 13th December, the first death as a result of Omicron in the UK was confirmed by the Prime Minister, with the Health Secretary announcing Omicron now represented 20% of cases in England.

This week, it was confirmed that 10 people with Omicron had been admitted to hospital in England, their ages ranging from 18-85 years. The majority had received two doses of a vaccination.

"Further information is needed to fully understand the clinical picture of those infected with the Omicron variant," stress the WHO.

Continue reading below

How contagious is Omicron?

Professor Rhode says early data indicate that Omicron could be faster spreading and contagious, but less severe - although he cautions that it is too early to tell whether the early indicators of lower severity in South Africa are applicable to other countries.

Evidence suggests the Omicron variant transmits more, and escapes immunity built naturally and through vaccines.

The Delta variant had high transmissibility, which allowed it to become the dominant variant of the virus. Compared with Delta, it's unknown just yet how contagious Omicron is. However, the news about how good it is at spreading is concerning.

Dr Sarah Jarvis, Clinical Director of, puts the risks into perspective. "Even if the risk of any one infected person being hospitalised or dying is lower with Omicron than with Delta, a much higher total number of infected people could still mean very high levels of death and hospitalisation overall. A small percentage of a huge number is still a very big number."

Exactly how the Omicron variant spreads may also differ from one country to another, depending on factors such as the number of vaccinated people, levels of partial immunity from previous infection and which variants were previously in circulation.

We will only know the true extent of Omicron's transmissibility once scientists have measured the basic elements of its life cycle - getting into cells, making more viruses, and leaving the cells to be transmitted. Once each of these stages has been measured in a laboratory, scientists can report what aspects of the variant make it more, or less, transmissible.

How does Omicron spread?

Professor Rhode says, like all variants to date, Omicron is primarily transmitted via the respiratory route.

The best ways to reduce your chances of becoming infected are to follow the same medical advice given in the early stages of the pandemic:

  • Get vaccinated.

  • Wear face coverings.

  • Wash and sanitise your hands often.

  • Remain socially distant from others.

  • Ensure good ventilation when mixing indoors.

It is particularly important with this virus to ensure you are have had a booster vaccination, with experts saying the term "fully vaccinated" only covers the first two doses. The government is strongly encouraging everyone to book their COVID-19 booster jabs, since data suggest Omicron will become the dominant variant by mid-December. Cases are now doubling every 2-3 days and while vaccine efficacy against symptomatic infection is substantially reduced against Omicron with just two doses, a third dose boosts protection to over 70%.

Continue reading below

When will we know more about Omicron?

"Most experts like myself and other scientists are working with partners to gather data and virus samples that can be studied. This research will help us answer important questions about the Omicron variant. Scientific experiments have already started and we are being fed new information constantly," says professor Rohde.

He also understands the panic and stress the general public might feel as a result of the blanket coverage of the new variant in the news, with little evidence to provide reassurance or clarity.

"We know how difficult this waiting can be, but we are learning in real time with this virus. It is especially difficult to know all the answers due to it being a novel virus that continues to mutate. This is what viruses do, especially when we do not have the global population fully vaccinated yet. There are too many pockets of non-immunised and/or poorly immunised people."

You should remain updated with the latest news to ensure you understand government guidelines and restrictions, and how to book your booster slot.

Article history

The information on this page is peer reviewed by qualified clinicians.

symptom checker

Feeling unwell?

Assess your symptoms online for free