Australian health officials will be keeping close tabs on the results of a trial which combines the flu shot and the COVID-19 vaccine.
Novavax has announced enrolment of the first participants in a study at a number of sites across Australia to check the safety and effectiveness of a combination vaccine using its seasonal influenza and COVID-19 jabs.
Results of the study are expected in mid-2022.
The Therapeutic Goods Administration, which assesses all COVID-19 vaccines before they can be used in Australia, will only register a vaccine if its benefits are much greater than its risks.
A health department spokeswoman told AAP the co-administration of a COVID-19 vaccine with other vaccines is "not routinely recommended as this can sometimes lead to a higher frequency of mild to moderate adverse events or make the attribution of potential adverse events to vaccination more challenging".
The Australian Technical Advisory Group on Immunisation currently recommends a preferred minimum interval between a flu shot and a Pfizer or AstraZeneca COVID-19 jab of seven days.
This can be shortened if there is an increased risk of COVID-19 or another vaccine-preventable disease, or logistical and scheduling issues.
A flu shot can be given before or after any dose of a COVID-19 vaccine, with a minimum interval of seven days.
"This advice is based on the current absence of data on the immunogenicity and safety of these vaccines when co-administered, and may change as further information becomes available," the spokeswoman said.
"The government is watching these developments closely and engaging with Novavax on possible commercialisation of this new vaccine, as we are for other promising vaccines in trial."
The early phase trial will comprise 640 healthy adults between the ages of 50 and 70 years who have either been previously infected with the coronavirus or given a COVID-19 vaccine at least eight weeks prior to the study.
"The combination of these two vaccines ... may lead to greater efficiencies for the healthcare system and achieve high levels of protection against COVID-19 and influenza with a single regimen," Novavax's Gregory Glenn said in a statement.
The federal government has 51 million doses of the Novavax stand-alone COVID-19 jab on order, pending TGA checks of the protein vaccine.
Australian Associated Press