28.DEC.2021 5 MIN READ | 5 MIN READ

Understanding Omicron, virus mutations and how we can continue to protect ourselves. Dr Asok Kurup, infectious disease specialist at Mount Elizabeth Hospital, shares more.

Last updated on 11 November 2022

Just as the COVID-19 situation appeared to be stabilising in Singapore, news broke about Omicron, a variant of the SARS-CoV-2 virus that causes COVID-19. While virus mutations were expected, encountering one so soon after Delta caught everyone by surprise. Naturally, there has been consternation over how this heavily mutated variant would affect people and whether it will derail plans to live with an endemic COVID-19.

To date, much still remains unclear about Omicron as scientists work round-the-clock to fully understand the new variant and how it may adversely affect people in a largely-vaccinated population like Singapore’s.

Dr Asok Kurup, infectious diseases specialist at Mount Elizabeth Hospital, explains more about virus mutations, what makes Omicron a ‘variant of concern’, and what we can do to keep ourselves safe.

Everyone is talking about the new COVID-19 Omicron variant. Why is it classified a ‘variant of concern’, and what exactly should we be worried about?

A variant of concern is designated by the World Health Organisation (WHO) based on evidence that the implicated variant – in this case Omicron – has several mutations that heightens its transmissibility, ability to avoid being repelled by the body’s immune defences, and increases re-infection risk.

More research is still ongoing to understand the Omicron variant better, but initial findings point to Omicron being staggeringly highly transmissible and having many mutations which make it possible to escape the body’s immune system. WHO has designated the Omicron variant as a ‘variant of concern’ because it poses an increased risk to global public health.

What do we know so far about the symptoms Omicron causes and its transmissibility?

While initial findings suggested that Omicron might be less severe than the Delta variant, this is becoming less obvious as the variant spreads across the globe. More data is needed to determine the impact of the variant on heavily vaccinated populations like Singapore. However, what is very striking is how much more transmissible Omicron is than any other COVID-19 variants we’ve seen previously.

How can we protect ourselves against Omicron?

How can we protect ourselves against Omicron?
Omicron is spreading at a lightning pace, and much more rapidly than other variants. That being said, do bear in mind that being vaccinated and maintaining precautions such as avoiding crowds, social distancing and masking up are crucial in mitigating the spread of COVID-19. These measures have also been effective against other variants like Delta.

How effective are current vaccines against the Omicron variant? What can we expect or look forward to for future generations of vaccines?

Singapore has recently added bivalent COVID-19 mRNA vaccines from Moderna/Spikevax and Pfizer-BioNTech/Comirnaty to offer greater protection against the original SARS-CoV-2 virus, and the Omicron variant(s). They help offer additional protection against newer COVID-19 variants, including XBB.

How can we be vigilant against community spread of Omicron in Singapore?

It is imperative that the young also get vaccinated and boosted where applicable for their age, and follow prevailing public health mandates. This is especially so during festive periods when there is a tendency for more crowds to form.

What about expectant mothers, parents with young children and individuals with compromised immune systems? What should they do?

Until more data is available, these individuals must be more careful when mixing with society. Where possible, they should get vaccinated, get boosted, and be very mindful about personal hygiene and masking up.

Does Omicron pose a threat of re-infection for recovered COVID-19 patients?

Does Omicron pose a threat of re-infection?
Limited data suggests that previous infection may offer less protection against Omicron in comparison to other variants of concern, such as Delta. There is also some preliminary data that details how vaccination may afford more reliable protection than natural infection. However more research has to be done before we can be certain.

How effective are our current testing methods (PCR and ART tests) in picking up Omicron?

The widely used PCR and antigen-based rapid diagnostic tests continue to be able to detect COVID-19 infections, including Omicron cases. We do not need to worry about being blindsided by our current testing methods in Singapore.

Can you tell us more about what causes virus mutations?

Viruses are constantly evolving and changing as they spread between people over time. Every time a virus replicates (makes copies of itself), there is potential for changes to its structure. Each of these changes is a ‘mutation’.

A virus with one or more mutations is called a ‘variant’ of the original virus. Some mutations can lead to changes in important characteristics of the virus, and affect its ability to spread and/or its ability to cause more severe illness or even death.

What are some other common types of viruses that often mutate?

Most commonly, mutations occur in the influenza virus, also known as the ‘flu’ virus.

What is your opinion on travelling, now that cross-border travel has resumed for some countries?

Is travelling safe?
At the moment there are parts of the world where Omicron is raging, like in Europe. Omicron cases are also rapidly increasing in the United States. Therefore, it is best not to travel at this time, and to defer non-essential trips to a later date.


Be it Omicron or other variants, COVID-19 affects everyone differently. Seek medical help if you experience persistent symptoms such as breathlessness and chest discomfort.

Our post-COVID evaluation service includes diagnostic tests and a specialist consultation to support your recovery. Contact us to find out more:

Mount Elizabeth Hospital: +65 6737 2666
Mount Elizabeth Novena Hospital: +65 6933 0000
Gleneagles Hospital: +65 6473 7222
Parkway East Hospital: +65 6344 7588


Article contributed by Dr Asok Kurup, infectious diseases specialist at Mount Elizabeth Hospital

Asok Kurup
Infectious Disease Specialist
Mount Elizabeth Hospital

Dr Asok Kurup is an infectious disease physician practising at the Mount Elizabeth Hospital, Singapore. His clinical expertise encompasses managing diverse infections ranging in complexity from outpatient to inpatient care. Conditions include community type infections (eg. influenza), tuberculosis, parasitic infections (eg. malaria), brain infection, pneumonia, skin, bone and joint infections, and surgical infections.