Associate Professor Siouxsie Wiles knows a lot about viruses. She heads up the bioluminescent (the production and emission of light by a living organism for us mere mortals) superbugs laboratory at Auckland University.
She is a proven standout communicator on coronavirus, in particular, and science, in general, in both the mainstream and social media. Further, Dr Wiles is also often viciously attacked in Cameron Slater’s far right blog. Credentials don’t often get as impressive as this.
One of her regular media outlooks is Newsroom which, on 20 December, published an excellent article from her: https://thespinoff.co.nz/science/20-12-2021/siouxsie-wiles-on-the-worrying-rise-of-omicron.
Dr Wiles discusses the worrying rise of the latest globally threatening Covid-19 variant, omicron. It has also arrived in Aotearoa New Zealand although to date all cases have been caught at the border.
The Gauteng experience
Dr Wiles focusses on omicron’s very high transmissibility noting that cases are rising really fast. She draws upon data analysis by Dr Ridhwaan Suliman (mathematician) in South Africa. Suliman analyses data from Gauteng.
Situated on the Highveld, Gauteng is one of the nine provinces of South Africa. Although the smallest province in that it only comprises 1.5% of the country’s land area Gauteng is a good choice for data analysis. But, within this relatively small area resides over 25% (nearly 16 million) of the nation’s population, including Johannesburg and Pretoria.
Dr Suliman compares the four main Covid-19 waves (southern seasons) – the first (winter 2020) followed by beta (summer 2020-21), delta (winter 2021), and omicron (summer 2021). Omicron’s transmissibility compared with the earlier waves is astonishing.
Comparing daily infection cases (based on seven day rolling averages) Omicron is presently nearly 10,000 per day. For the same number of days delta was around 8,000 (the first two waves were about half delta’s).
This rings obvious alarm bells as delta subsequently reached its peak daily case rate of over 10,000. But it is early days for omicron. To the extent that waves are connected for convenience with seasons omicron, has experienced less than half a season in Gauteng.
Suliman’s data records a slight dip (previously it had been just above 10,000) although there was an earlier small dip quickly followed by a bigger rise. Delta’s current daily rate has now fallen to below that of the first two waves for the same length of time.
Further, the effects of vaccination rates have to be factored in when considering the implications for New Zealand. Our vaccination rate for the whole population is 75% (76% in Australia). Compare this with South Africa’s 26%. This does put us in a much better position all other things being equal. But this is different from being in a good position.
Dr Suliman also looks at weekly hospitalisation rates in Gauteng comparing them with the earlier Covid-19 waves. Hospitalisations are seriously on the rise. Currently it is around 3,000 (per capita roughly 1,000 in New Zealand). Delta at its peak was around 6,500 but is now declining.
Allowing for big differences in vaccination rates, Gauteng is consistent with what is happening internationally including across Europe. Even though delta continues to surge in the United Kingdom, it has been swamped by omicron as the dominant strain. Across the Tasman New South Wales has rocked up to over 2,500 cases a day compared with around 500 a week ago.
Omicron a milder variant?
It has been suggested that the effects of omicron are milder than delta although this is now being challenged. One has to be very cautious in drawing firm conclusions. Dr Wiles notes research revealing that omicron was 70 times better than the delta variant at infecting and replicating in bronchial tissues and 10 times worse at infecting and replicating in lung tissue.
Hospitalisations and deaths normally lag cases by several weeks as it takes time for people to get very sick, and sometimes they can be in intensive care for weeks to months before they die. Not enough is known about the effectiveness of vaccines against serious illness and death and what happens to people who aren’t vaccinated who get omicron.
As Dr Wiles points out: “…even if does turn out that omicron causes a milder illness for most people, that won’t be the case for everyone. And because of the sheer volume of people catching omicron, hospitals are still likely to be overwhelmed. We also don’t yet know whether those who have a mild illness from omicron will go on to develop long covid and be impacted for life.”
Timely advice for New Zealand’s response
Public health specialists at Otago University have published in their online publication Public Health Expert very timely quality advice on how to respond not just to the delta threat but now also omicron: https://blogs.otago.ac.nz/pubhealthexpert/covid-19-christmas-the-new-year-and-summer-holidays-what-the-nz-government-and-individuals-can-do-to-minimise-the-risks/.
The article is written in the context of encouraging progress now being made in reducing the delta threat with significantly decreasing infection rates in Auckland and well contained to small numbers in a small number of other provinces. Increasing vaccination rates have clearly made a big difference. Their focus is on strengthening international border security and a range of public health measures. It is recommended reading.
It is unfortunate that we have just got back to September when Auckland was trending downwards. The decision to lower alert levels from 4 to 3 was too early and contrary to the advice of the Government’s modellers (the Government was let down by wrong Health Ministry advice).
This unwise decision meant more than just a delay of around two months. It also meant a subsequent exponential increase in infections and hospitalisations leading to an avoidable longer overall lockdown.
Aotearoa would be in a much better place now if external experts had not been kept out of the loop and been able to directly and proactively access government. The reality is, like most other areas of health, most of the expertise rests within the health system but outside the Health Ministry. If omicron is to be successfully combatted this expertise should not be allowed to be so disengaged again.
Where we are at
But we are at where we are at. There is a big question mark over whether the combination of loosing restrictions and the festive season will lead to a further delta surge. This is now made worse with the arrival of omicron at our border.
The most critical response is better securing the overseas border from omicron. The Government’s announcement yesterday of delaying the returnees from Australia until the end of February, reducing the time between the second vaccine dose and first booster to four months, and the 5-11 year olds vaccine rollout are good strong steps in the right direction.
This announcement suggests a veering back to the zero tolerance approach which has served New Zealanders so well, at least until October this year.
But it appears that on average we have a case of community transmission after every 200 or so overseas arrivals in managed isolation and quarantine. As hard as it will be the tap of arrivals needs to be significantly slowed down, particularly from high risk countries (there are many), to ensure numbers are safely manageable.
This slowdown would be at least until good progress has been made with vaccinating 5-11 year olds, providing boosters to the already vaccinated, and further improving vaccination rates for those over 12 years (or much more is learned about the effects of omicron).
When asked whether the French Revolution of 1789 was a good idea Chinese revolutionary Mao Zedong is reported as saying that it is too early to tell (actually I think it was his fellow revolutionary Zhou Enlai).
Regardless of who said it, what is certain is that while it is too early to say what the effects of omicron will be, it will not be very long before we do.
Continuing the zero tolerance approach evidenced yesterday by government, including its scope, will make the difference between success and failure.