About the new variant Omicron

THERE is a lot of anxiety in the air about Omicron especially when we see governments globally reacting to the new threat. In Singapore, our Ministerial Task Force has already outlined new measures including further testing of those coming in through our vaccinated travel lanes.

We have seen outright travel bans and border closures by Japan and Israel. The WHO has declared the new South African variant as a Variant of Concern and named it Omicron. They have skipped Greek letters Nu and Xi for obvious reasons. The South African medical community has been on the ball, had rapidly sequenced the new variant and alerted the world.

You may recall that South Africa generated the Beta variant and hence they have been on the alert for the presence of a new variant. We know that Omicron was first found in a patient in Botswana on Nov 11 and the World Health Organisation believes that the spread of Omicron variant started on Nov 24.

The mutations you may have read about on the spike protein of the new variant has numbered more than 30 mutations. The scientists are surprised by the number of mutations. This compares with the 2 critical mutations in Delta and the 3 critical mutations in the spike protein of the Beta variant. What this means is that mutations may impact the transmissibility, increase severity and resistance to the antibodies we mount against it.

At the moment , we are 2 weeks into the spread of Omicron and still do not have all the answers. The mutations may look frightening but what remains to be seen is how the virus behaves at ground zero. We know that in the provinces in South Africa the virus is spreading and displacing Delta. A new variant is like a new challenger to the boxing ring, it needs to fight the incumbent Delta and beat it at its own game.

For the Omicron to be dominant, it needs to be able to evade the antibodies we mount against it; be it from previous natural infection or from vaccines. If the variant has a lot of mutations, it can evade the neutralising antibodies that we have as a first line of defence against the virus. However, the mutations cannot be so numerous that they result in the ineffectiveness of the spike protein to attach to the target called the ACE receptor.

Some of the mutations can result in efficiency of the spike protein. There are 2 parts to a spike protein, we call them S1 and S2. The S1 subunit attaches itself to the target ACE receptor and S2 subunit shoots out tentacles to attach the virus to the cell surface; the tentacles pull the virus towards the cell surface and fuses the virus and the lung cell membranes similar to the way a squid captures a prey.

Yet other ways the mutations can affect the immune system is to throw into chaos the role of interferons. Interferons are a first response by the immune system when the virus arrives. The role is to trigger a host of reactions by activating T cells to attack virus infected cells, stopping viral replication and triggering memory cells to gear up the response to an old enemy. However these interferons have dual nature like "yin and yang" and work in tandem to snuff out the virus. Yet the variants can have mutations that suppress the interferons selectively, upsetting the delicate balance and triggering what we know as Cytokine storms.

The jury is still out as to what the Omicron can do. Can it outperform Delta and become the dominant force? Is it highly infectious and therefore can trigger another wave of infection during the coming winter? Will it result in severe disease that will skyrocket mortality and overload healthcare systems?

We have some answers but not all. We know that in Gauteng province of South Africa, the cases are increasing exponentially and the Omicron seems to be edging out Delta. It is too early to tell if it is going to cause severe disease as deaths usually lag infections by 2 to 4 weeks. We know that it is detectable by PCR testing and has a unique signature. The data suggests there is some increase in hospitalisation figures in the last week but it is really too early to tell.

We also spoke to Dr Angelique Coetzee last Saturday; she is the chairperson of the South African Medical Association and a clinician in Pretoria , the epicentre of the Omicron outbreak.

She told us that the patients she and her colleagues in the region have seen are younger, usually below the age of 40 and have mild symptoms with lots of fatigue. They do not seem to run into trouble as yet in terms of requiring oxygen supplementation or hospitalisation. The patients affected include vaccinated and partially or non-vaccinated patients.

On the global front, there is concern as there are 3 patients in Israel who are community cases and hence their reaction of border closure. In the Netherlands, there were 600 passengers from two flights that arrived from South Africa and 61 passengers tested positive. In Hong Kong, there was a passenger that was positive whilst in quarantine on Nov 13 and he infected the fellow passenger across the corridor in the quarantine hotel.

This must have brought traumatic flashbacks to those of us who recall the Sars outbreak in the Metropole hotel in Hong Kong in 2003.

In Japan, the Delta virus in its successive iterations seems to have mutated into some kind of evolutionary dead end. The number of cases now average less than 100 daily; down from a peak of 20,000 cases or more daily in August. They are very concerned that the Omicron variant will start a new wave of infections and hence the border closure.

Life must go on

While we are waiting out the next 2 to 3 weeks with bated breath for clarity to emerge, what can we do? Life must go on, get vaccinated if you have not done so, get a booster jab if you have not done so, mask up and use the ART kits provided if you have any symptoms.

In the last 10 months we have vaccinated some 6 billion patients and built a wall against the virus. The virus has proven to be a formidable enemy and the Delta variant found a way through the wall and infected those who have waning antibody levels. Now the Omicron variant threatens to do the same if not worse.

I have asked my patients to get booster jabs. They can also do a CPASS test. This is where we can measure the neutralising antibodies either before or after they have done their boosters; or before they travel. The CPASS test is measured in terms of percentage. A level of 80 per cent and above is protective; this means the neutralising antibodies in the blood are able to block the binding of the ACE receptor target and a part of the virus spike protein. This gives them confidence as an objective way to measure their protection against Delta or other variants.

As we count down towards the end of 2021, we wish and are hopeful that the dual Annus Horribilis of 2020 and 2021 will draw to an end and we look forward to a new Annus Mirabilis of 2022. I take the opportunity to wish all our readers the joyous greetings of the festive season.

• This article is produced on alternate Saturdays in collaboration with Royal Healthcare Specialists Centre