With news surrounding the latest Covid-19 variant – Omicron – dominating news headlines this week, health experts have their say about this ‘new variant of concern’, and what it means for Australians.
‘Unsettling but far from unexpected’
Dr Deborah Cromer, Group Leader in Infection Epidemiology and Policy Analytics at the Kirby Institute, University of New South Wales says that “the emergence of a new variant, though unsettling, is far from unexpected”.
“Viruses constantly mutate and take on new forms, and the level of existing immunity against a new variant is key in determining the impact an emerging strain will have,” says Dr Cromer.
“Scientists will now need to quickly use established laboratory methods to determine how much immunity, blood from vaccinated people has against Omicron and we will then be able to use the established relationship between immunity and vaccine efficacy to predict how existing vaccines will perform against Omicron, and therefore how much impact this new variant may have on the inroads we have made in the fight against Covid-19 disease.
“Closing borders may buy us some time to gather the data to answer these questions – however, as we have seen previously with both the original strain and with Delta, a virus will ultimately find its way past these barriers, and it will come down to how effective the immunity we have generated to date is against the new variant,” she says.
‘Not all Covid variants cause trouble’
Perhaps as a way of calling for calm, according to Associate Professor Sanjaya Senanayake, a specialist in Infectious Diseases and Associate Professor of Medicine at The Australian National University, “not all Covid-19 variants cause trouble”.
“Lambda and Mu have not taken off globally. So, it is possible that the new variant, Omicron, could hopefully fizzle out,” says Associate Professor Senanayake.
“But Omicron is troubling in terms of its mutations and the limited infections that have been seen in people.
“It has a lot of mutations, more mutations than seen before with previous variants.
“Many of these are on the spike protein and the receptor-binding domain.
“Some of these mutations can increase the transmissibility of the variant, while others can help it evade the immune system: a worrying combination,” she adds.
Associate Professor Senanayake also points out that “the WHO [World Health Organisation] has said that there’s an increased risk of reinfection with Omicron compared to other variants of concern”.
“The WHO suggested that it is growing at a faster rate than previous infection surges, indicating it could be more infectious than Delta,” she says.
“The limitations here are that it is still early in the discovery of the variant, so time will tell if these initial trends persist. It will also take time to determine the effectiveness of our current vaccines against Omicron, involving both observational and laboratory data.”
Associate Professor Senanayake says that the outbreak of this new variant, that “emerged in a country where only 25% of the population is fully vaccinated” is a “stark reminder to developed nations that when it comes to Covid and vaccination, we have to … ensure that the whole world gets vaccinated in a timely manner”.
‘We already have weapons to reduce the risk of becoming infected’
While this new variant presents concern due to its number of mutations in the spike proteins, which may give this variant a better way to evade antibodies from vaccines, Dr Vinod Balasubramaniam, a virologist at the Jeffrey Cheah School of Medicine & Health Sciences at Monash University in Malaysia, says that “this should not deter the current worldwide vaccination drive, including booster doses”.
“We should not forget that already we have the ‘weapons’ (e.g., masks, social distancing, proper hand hygiene etc.) to reduce the risk of becoming infected,” says Dr Balasubramaniam.
“It should therefore be our main goal to slow down virus spread by adhering to the existing hygiene and speeding up the vaccination, including booster doses process (especially in vulnerable populations).
“Getting vaccinated against Covid-19 is the strongest form of protection.”
‘Will it outcompete Delta’
According to Dr Stuart Turville, an Associate Professor in the Immunovirology and Pathogenesis Program at the Kirby Institute, UNSW Australia, “what we know about the current variant comes from the work on all other variants and the science that has looked at predicting what variants may turn up in the future”.
“Key now is how this virus will expand in the real world,” says Dr Turville.
“That is: Will it outcompete Delta? Will it have a higher R-value? Will it be associated with vaccine breakthroughs or primarily unvaccinated? If a breakthrough occurs frequently, is it related to evasion from antibodies? What will the disease severity and mortality rates be for this variant in both [vaccinated and unvaccinated] groups? Will prevalence in children be, low and [what about] disease severity?
“At this stage, the numbers are too low to have the above real-world data.
“At this stage, we don’t know, and it’s a: watch and see.
“Closed borders only buy some time for some countries. In many cases, the variant may be already in the community.
“Pragmatically, good quarantine is a better option and enables the study of the virus with no community spread.
“We did this in 2021 and developed rapid systems to understand viruses like this within one week within the lab. We did this recently for Lambda.”
‘Yet to understand if Omicron is a threat’
Catherine Bennett, Chair in Epidemiology in the Faculty of Health at Deakin University, says that “we are yet to understand if Omicron is a threat”.
“There are enough warning signs to warrant the precautions to limit global spread – the larger number of mutations focussed in the same area of the spike that most vaccines target, a rapid rise in cases in South Africa linked to its emergence, and reports of high rates of reinfection.
“It is not yet known how effective current vaccines are against Omicron as vaccination rates are low in South Africa, with only 24% fully vaccinated.
“They have just come out of a large Delta wave yet are reporting worrying rates of reinfection.
“There are also high rates of people living with HIV and AIDS in southern Africa, which makes it more complicated to interpret the effectiveness of either vaccine-induced or natural immunity against infection or serious illness.
“Until we know more about the threat this variant might pose in Australia, it is wise to take precautions to prevent community transmission,” she says.
