Australian health departments have failed to publicly explain the presence of a “worrying” variant of Covid-19 in Australia identified by UK researchers from a global genomic database of samples.
The variant, known as B1525, was picked up by researchers from the University of Edinburgh who were examining samples taken from GISAID, a global genomics database, in order to look for potential mutations in strains of Covid-19 that should be targeted in future testing.
The earliest case of the new mutation found in Australia was 17 January 2021, but so far health departments have been unable to say where the two cases identified may have been.
B1525 differs from the B117 virus found in England and the B1351 strain that originated in South Africa thanks to a set of mutations that include E484K – a mutation to the spike protein on the outside of the virus that plays a role in helping it to enter cells.
The E484K mutation is suspected to have contributed to making the South African and Brazilian variants of the virus more resistant to antibodies seeking to eliminate it – a development that may prove problematic for vaccine rollouts.
While the study turned up 35 samples of B1515 from Denmark and 33 from the UK, two instances were found in Australia with the earliest being recorded on 17 January 2021.
The exact point of origin of these samples within Australia remains unclear, but they are likely to have been introduced by travellers returning through the hotel quarantine program.
State and federal health authorities so far contacted by Guardian Australia say they have no record of B1525 being detected in their testing, and most have only recorded the South African and English variants.
Health services in Western Australian, South Australia, Victoria, and the Northern Territory say they have not detected the variant. Other states and territories are yet to respond officially.
Prof Peter Collignon, an infectious diseases physician with Australian National University, said authorities may have picked up the new variant in their regular testing but not recognised it if they hadn’t known to look for it until now.
This is due to the way genomic sequencing works. Where a particular virus has been sequenced, it appears as raw data that is uploaded to an Australian website. That information is then shared globally for other researchers to conduct further investigations.
For it to have meaning, health authorities need to know to look for a particular variant and then interpret a sequence against other epidemiological information that has been collected.
“I’m not the most expert on the genomics of Covid-19 but it is entirely possible that they may have picked it up in their testing and did not know they picked it up,” Collignon said. “It happens with other viruses and bacteria where people sequence a genome, upload it, then other people do a search, find it and say, ‘hey, this is what we’ve got!’
“That’s the point of having these genomic banks, that’s the point of uploading this information to these databases so other people can investigate.”
In a statement, federal health authorities said they were aware of the variant but not where it has been recorded.
“There is scant information about B1525 and importantly no epidemiological data about whether this variant is more transmissible or causes any change in disease severity,” the statement said.
“Although one of the nucleotide mutations, E484K, has been suggested to resist the immune response from people previously infected or vaccinated with some vaccines, the data on this is limited and not yet conclusive.
“An early and very small study in South Africa showed one vaccine had limited impact against mild disease severity. There is no information on the impact on more severe disease and further work is required.”
The department also said B1525 did not include the specific mutation that was known to make the UK strain more transmissible.
Prof Catherine Bennett, chair in epidemiology at Deakin University, said she was not aware the variant was present in Australia but said the work done in the study was “important”, particularly for the rollout of future vaccines.
“The [mutation identified] is called an escape variant as it seems to slip under the immunity radar in people previously infected by other variants of the virus and is associated with reduced vaccine efficacy – though some vaccines, like Novavax, still have workable efficacy and that’s good news,” Bennett said.
“When this mutation and other immune escape mutations combine with other mutations, that might signal greater transmissibility or the capacity to cause more serious illness. Hence the concern of this E484K mutation appearing in the old B117 variant from the UK.”