Is Omicron the variant that will end the pandemic?

IT HAS been 8 weeks since I wrote about the Omicron variant and what 8 weeks it has been! We have seen record number of cases globally with huge case numbers in North America, Europe and in Australia. We have seen huge numbers peaking at a million cases daily in the United States with 150,000 hospitalisations and 3,500 deaths on a single day last week.

On a global scale, the cases have soared to a peak of 20 million cases with 45,000 deaths in the last week. The Omicron is now the dominant force in most countries and in the South Africa epicentre, the cases have peaked with the deaths about 20 percent that of their previous Delta wave. In Singapore, we have seen new growth in cases since Jan 4 this year with 4,832 local cases on Jan 26 and we are now in the midst of an Omicron wave.

The Omicron is faster in many ways compared to Delta. The Omicron takes a shorter time of 2 days to infect the next person compared to 3 days for Delta. The patient with Omicron also infects 3 to 4 patients more than a patient with Delta.

The interesting thing I found is that the Omicron multiplies 70 times more rapidly in the tubes or bronchioles of the lung and 10 times slower than Delta in the air sacs. Hence the Omicron patient has a lot more virus in the tubes in the lung allowing spread when talking and breathing.

However, the Omicron is less severe than the Delta due to the its slower speed of reproduction in the air sacs of the lung. In 2,252 initial Omicron cases in Singapore, only 3 required oxygen and none needed intensive care.

Nevertheless, we still have 38,000 unvaccinated seniors in our midst and Omicron may be milder than Delta but it can still wreak havoc among the unvaccinated. Our local figures show that the vaccinated were 10 times less likely to be in the ICU or to perish compared to those who are not vaccinated.

In the US, the unvaccinated were 16 times more likely to be hospitalised and vaccination reduced death by 68- fold.

So how effective is the vaccine against the Omicron? The Pfizer and Moderna vaccines don't work so well against the Omicron as compared to the Delta. By 6 months, the vaccine effectiveness against Omicron for hospitalisation and/or catching the disease had dropped to low levels and hence a booster is critical.

Upon boosting, the effectiveness goes back up to about 88 per cent. It is good to see that 91 per cent of us have been vaccinated and more than half of us have had a booster dose.

The Omicron is highly transmissible and formidable, so we have to continue with our masking, social distancing, personal hygiene, good ventilation and ART testing. We know that masking and personal hygiene reduces transmission by half and social distancing by a quarter.

A more refined way of differentiating masks would be that if you spoke to an infected person who is not wearing a mask, you can speak to that infected person for 30 minutes if you are wearing a surgical mask without catching the virus.

If you are wearing an N95 mask, you can talk to that person for more than 2 hours without getting ill. I wear an N95 mask at work but also make sure I wear an N95 if I am going to a high traffic area like a market, hawker or shopping centre. There are now several comfortable models of N95 masks available.

One of the current topics that we are all invested in is the vaccination programme in our children who are 5 to 11 years old. We have rolled out vaccination in our children since early this month and have vaccinated 140,000 children so far with no major adverse side effects.

The results have been good with high levels of neutralising antibodies after the second dose. These neutralising antibodies are highly protective against catching the disease.

We must balance this against the risk of 14,380 children ages 12 and below who caught Covid since October and 2,586 who were hospitalised. Four of the children hospitalised required oxygen or intensive care while 15 developed Multi system inflammatory syndrome(MIS-C).

This MIS-C is an illness where the virus triggers the immune system to attack the heart, lungs and kidneys. It is very similar to Kawasaki's disease which you may have heard of.

In the US, there were 1.9 million children ages 5 to 11 who caught Covid and 8,300 were hospitalised with 94 deaths. In addition, about 7 per cent of the kids had Long Covid and 5,200 had MIS-C. Those who were hospitalised; about a third went into intensive care and those who had MIS-C, two thirds were in intensive care.

If you are not familiar with Long Covid, it kicks in after 4 to 12 weeks from date of infection. There are lots of symptoms in Long Covid involving all parts of the body. So, Covid is not a mild disease in children after all, and hence we can justify the vaccine.

At the same time, we are already having mandatory vaccinations against diseases like chickenpox, rubella and meningitis that are far less serious than Covid. Furthermore, in young children the spread of the Omicron is rapid and there is also spread to adults and elderly in the household.

One of my patients is a teacher who delayed her booster till school reopened and promptly caught Covid, presumably from her students. So we should not delay our boosters and we should also vaccinate our children.

In the way forward, we must reduce transmission so we can reduce risk of more variants. One of these variants has already emerged and that is a slightly different version of Omicron. This is called BA2 and it has 85 mutations as compared to 60 mutations in BA1 or the original Omicron.

It looks like it could be faster, though not more severe, and the vaccines are still effective against it. However it has lost that distinctive unique signature when we run a PCR test on it.

In the final analysis, is Omicron the variant that will end the pandemic? It is highly transmissible and less severe; which is the way all viruses want to go. We cannot be too optimistic and the huge numbers are putting a strain on health systems and disrupting industries and supply chains. We are seeing massive pump priming and the global economy is starting to overheat with inflationary pressures appearing.

The pandemic has certainly shown its propensity to come at us with all the different heads of the mythical Hydra. We need Hercules with his sword of truth to release us from the scourge. Surely we can find our Heroes in our healthcare workers, our scientists to develop diagnostics, therapeutics and novel vaccines and our leaders to steer our economies, build resilience and to marshall our resources to transit into this new normality.

This article is produced monthly in collaboration with Royal Healthcare Specialists Centre