Coronavirus: Why 'Omicron' might not be as scary as it sounds, and the advantage NZ has

A Kiwi epidemiologist is urging calm over the emergence of the 'Omicron' variant of COVID-19, saying there's no solid proof it's as bad as the headlines would have us believe - yet.

First discovered in South Africa thanks to its sophisticated virus-tracking infrastructure, Omicron appears to have taken two weeks to displace the highly infectious Delta variant. It has many more mutations too - including on the spike protein - linked to increased transmissibility and raising concerns it could render vaccines less effective.

"This variant caused alarm amongst virologists because it has a very large number of mutations - more than 50 - and some of these mutations affect the structure of the spike protein, which is so important for the effectiveness of vaccines," epidemiologist Michael Baker told Newshub Nation on Saturday.

"The other factor is it appeared to be outcompeting the Delta variant in an area of South Africa. That really means it's tipping the balance into this category of 'variant of concern'."

Dr Baker said while it seems likely Omicron is more infectious than Delta - which was already twice as catchy as the original SARS-CoV-2 virus - that might not be the case.

"We may be seeing a founder effect with the pattern of spread in South Africa," said Arindam Basu, epidemiologist at the University of Canterbury. 

"A founder effect is one where a selection of initial genetic patterns dominate in the cases we get to see - not necessarily because the virus itself is more transmissible."

After suffering a third wave of infections through mid-2021, South Africa recently got its daily case numbers down below 1000, low by world standards - so what Dr Basu is saying here is that although the rising case numbers are dominated by Omicron, it could just be because Omicron was the variant present at that inter-wave bottleneck, so is contributing more genetic material to new cases than other variants, like Delta.

Dr Basu said Omicron might well be more infectious, but it's simply hard to tell at this stage.

"Having said that, and given what we know about Delta, it is likely that Omicron strain will enable the virus to propagate fast in populations. The effective reproduction number (which measures the potential for COVID-19 to spread) is likely to be higher than that of Delta. That then will have the undesirable effect of fast transmission."

Computational evolution scientist David Welch of the University of Auckland said it's possible Omicron benefitted from a superspreader event, making it appear more transmissible than it really is.

"As experiments are run and we observe what is happening over the next few weeks, we will be able to answer this question more precisely. In the meantime, we should be preparing for the possibility that it will spread faster than Delta."

As for the vaccines developed last year to fight off the original virus, they're still likely to work against Omicron despite its numerous mutations, Dr Basu said.

"The Pfizer vaccine is built against a specific protein of the virus that helps it to enter human cells and replicate. That has not changed with Omicron as far as we know; hence the vaccine will still be protective."

Microbiologist Siouxsie Wiles is a little more concerned, saying more than 30 of the mutations are on that spike protein, calling it a "real worry".

And Miguel Quiñones-Mateu, viral pathogenesis expert at the University of Otago, said it's "difficult for the virus to evolve/select" for the "trifecta" of being infectious, deadly and good at evading vaccine protection.

"However, having a canvas of 8 billion people to explore, who knows, it may be just a matter of time." 

Dr Baker said while Omicron has mutations, it's still recognisably SARS-CoV-2, so vaccines are "still our best defence at an individual level".

Dr Welch said if it is easier to spread amongst the vaccinated, it's the unvaccinated who should be most worried, as they'll be exposed to more potential cases but lacking the protection against serious illness.

But the unequal distribution of vaccines worldwide is likely partly to blame for the emergence of new variants like Omicron, experts say. Rich nations have started giving citizens third doses, while much of the developing world hasn't had their first yet. South Africa's coverage is less than 25 percent.

"The fact that this variant has emerged once again highlights how badly the world is handling the pandemic," Dr Wiles wrote in a piece for The Spinoff.

Dr Quiñones-Mateu backed this up, saying if everyone got vaccinated "more or less at the same time", the virus' ability to find new hosts and evolve would have been muted.

"More importantly, I know that in some countries, where access to COVID-19 vaccines is scarce or less-than-optimally planned, people are mixing and matching different vaccines, at times not following the appropriate schemas. Similar to taking antibiotics without prescription or antiviral strategies without the proper guidance, all this could put pressure on the virus, perhaps leading to escape variants.

"The misuse of vaccines and therapies will only accelerate the selection of 'something nastier'. Vaccinating as many people, in a relatively short period of time, has to be the goal, and staying away from misusing antiviral treatments."

As for whether it'll reach New Zealand, Dr Welch said it's inevitable - but we have a chance to get more people vaccinated before it does. 

"There could be a benefit in delaying its arrival through keeping up border restrictions such as MIQ requirements for longer than currently planned. The time bought by this could be used to vaccinate 5-12 year olds, increase vaccination rates across the whole population, and provide booster shots to people who are five months or more past their initial two doses. This would better prepare us for its arrival."