As Australia enters an “eighth wave” of COVID-19, 2 updated vaccines could soon be available to the public.
In early October the Therapeutic Goods Administration (TGA) approved two updated COVID-19 vaccines: the Spikevax XBB.1.5 (andusomeran) by Moderna, and Pfizer’s Comirnaty Omicron XBB.15 (raxtozinameran).
These are monovalent vaccines, each containing one component that corresponds to a single variant of SARS-CoV-2 – the virus that causes COVID-19.
These two updated vaccines specifically target a subvariant of Omicron called XBB.1.5, also known as Kraken, that is part of the XBB* sub-lineage whose variants are currently dominating infections in Australia.
A spokesperson for the Department of Health and Aged Care told Cosmos that: “In the 28-day period between 9 October 2023 – 5 November 2023, the Australian genomic surveillance system AusTrakka reported that recombinant variants continue to be the predominant sub-lineages being sequenced.”
“Of all uploaded sequences in the reporting period, 84% of recombinant sequences belonged to the XBB* sub-lineage.”
Of those, one in particular, EG.5.1, also known as ‘Eris’, is the main sub-lineage identified.
Recombinant variants emerge when the genomes of two SARS-CoV-2 virus combine to form a new variant that is different from both parent lineages. This can happen when a person is infected with two variants at the same time.
“The currently available vaccine formulations continue to provide strong protection against serious disease and continue to be widely available across the country,” said the spokesperson.
“As expected, each generation of vaccines has been superseded by newer vaccines targeting the strains of the virus now circulating.
“Monovalent XBB vaccines are expected to provide modestly enhanced protection from severe disease compared to older vaccines.”
However, before they can be rolled-out the Australian Technical Advisory Group (ATAGI) must assess them further.
ATAGI is expected to provide advice to the minister for health and aged care on the potential use of XBB vaccines in coming weeks.
Drug manufacturers do not always seek regulatory approval at the same time worldwide which leads to different approval and rollout times globally.
Official advice for those wondering if they should get the existing vaccine booster or wait for the new one is not to wait.
“ATAGI continues to encourage all adults who were recommended to have a COVID-19 vaccine dose in 2023 who have not yet had one, to receive a vaccine dose as soon as possible.
“Vaccines containing the original/ancestral strain have demonstrated protection against severe disease from a broad range of SARS-CoV-2 variants, including Omicron and its subvariants,” the Department says.
The Australian Technical Advisory Group on Immunisation’s (ATAGI) recommends all adults aged 75 or older should receive a 2023 COVID-19 vaccine dose if 6 months or more have passed since their last dose.
ATAGI also advises that people aged 65 to 74 years, and adults 18 to 64 years with severe immunocompromise, should consider an additional dose if 6 months have passed since their last vaccination, and discuss it with their healthcare provider.