The world may not learn the true level of threat posed by the new Omicron variant of Covid-19 for several weeks, says a University of Otago scientist.
University of Otago evolutionary virologist Jemma Geoghegan says Pfizer and Moderna have indicated they could update their existing vaccines to account for Omicron's spike protein changes within 100 days. Photo: University of Otago
Evolutionary virologist Jemma Geoghegan told Nine to Noon patience was crucial as labs and scientists worked to gather information on Omicron.
Dr Geoghegan said while lab experiments were currently underway to determine whether existing vaccines were effective against the new variant, it would take time to collate the data.
"Scientists will be growing this virus in the lab and testing it against … blood that contains antibodies from past infections or vaccines, to see whether or not it's effective against this variant."
However, it was also epidemiologically important to keep an eye on what was happening in the real world, she said.
"What happens in the lab doesn't necessarily equate to what's happening out there in the world, so it will be several weeks until we see whether or not there is an increase in hospitalisations and deaths [driven by the Omicron variant]."
The fact Omicron appeared to be "outcompeting" Delta in some regions of South Africa was quite surprising, she said.
"We thought Delta was extremely well-adapted to spread between humans as it was very infectious, very contagious, it basically replaced all other variants around the world, so the fact that Omicron is now outcompeting that means that it's probably more fit ...
"I think it's right to be concerned at this moment, but we need to know more."
Geoghegan believed it was likely current vaccines would still reduce the severity of the new variant, and said pharmaceutical companies had indicated they could "tweak" their existing vaccines to account for the spike protein changes Omicron displayed within 100 days.
This was possible because mRNA vaccines like those made by Pfizer and Moderna "basically provide an instruction for your body to make copies of the spike protein", she said.
The existing vaccines provided the instructions to make "the original spike protein that first emerged way back in Wuhan nearly two years ago", Geoghegan said, "however, if [the vaccine manufacturers] need to update that, they would use a spike protein from a current variant".
"It sounds quite simple and it is a relatively simple process, but obviously then there's ... safety testing to go on."
Such vaccine modifications, coupled with drug therapies that were showing a "significant layer of added defence" would help in the ongoing global fight against the virus, Geoghegan said.
"It's unlikely that the vaccine that we currently have doesn't provide [any protection], so ... it's a good basis that we have over 90 percent coverage and we have to remember that Delta is actually still the most dominant variant world-wide ...
"In comparison to Omicron, Delta is more likely to keep entering New Zealand than any other variant, because it is literally in every country that's doing genomic sequencing and it is the dominant variant."
The global community's failure to ensure equitable distribution of vaccines to all nations had likely contributed to the rise of the Omicron variant, Geoghegan said.
"Southern parts of Africa have the lowest vaccination coverage in the world," she said, noting that the region's ongoing HIV/Aids epidemic meant there was also a high number of immunocompromised individuals in the population.
"With variable Covid vaccination rates compared to the rest of the world, this scenario will allow SARS coronavirus to keep evolving ... it provides sort of a training ground for it to evade immune response and keep transmitting to infect new cells," she said.
"It could have been likely that these mutations accumulated within an immunocompromised host, with extensive intra-host evolution."
Geoghegan said while early reports out of South Africa indicated Omicron caused only mild symptoms in patients, precautions should still be taken until more data was collected.
"Initial reports of these infections suggested mild disease but these were among younger people who tend to have more mild disease anyway, so we need a better understanding of the level of severity of the Omicron variant at a population level, I think."
