A new stronger flu vaccine will be introduced in Australia in 2016 following a record number of cases of the virus this year.
The vaccine will cover four flu strains, instead of the usual three, including two influenza B strains.
There were 90,000 cases of flu in Australia during their 2015 winter - 25,000 more than the previous year.
The UK's vaccine for adults protects against three strains, as recommended by the World Health Organization (WHO).
It sets out which strains of the virus should be included in flu vaccines in advance of the season for the condition. which in the northern hemisphere happens each February.
During Australia's recent winter, most of the flu cases were thought to have been caused by circulating influenza B strains.
As a result, the new vaccine will include both the Brisbane and Phuket B strains of the flu virus.
Australian Health Minister Sussan Ley said the move to a "quadrivalent" vaccine would mean the best possible protection would be available free to the people who most needed it.
In the UK, the flu vaccine used last winter had an unusually low effectiveness of 34% against the main circulating strains.
A trivalent vaccine is being offered to vulnerable adults in the UK this winter to protect against three types of flu virus:
A/H1N1 - the strain that caused the swine flu pandemic in 2009
A/H3N2 - a strain that can infect birds and mammals and was active in 2011
Each year, the viruses that are most likely to cause flu are identified in advance and vaccines, recommended for worldwide use by the WHO, are made to match them as closely as possible.
Children are given a nasal spray flu vaccine which protects against four strains of virus, including a strain that was active in 2008.
Youngsters are given extra protection because they are the main spreaders of flu so this helps to protect the general population.
Public Health England says that although it's not possible to fully predict the strains that will circulate in any winter season "flu vaccine remains the best protection we have against an unpredictable virus which can cause severe illness and deaths each year among at-risk groups".
The at-risk groups include:
the very young
those with underlying disease, particularly chronic respiratory or cardiac disease
Dr Richard Pebody, head of flu surveillance for Public Health England, said more than 3.3 million children across England would be offered the nasal spray flu vaccine this winter, based on a quadrivalent vaccine, which includes two influenza B strains.
"Influenza infection is more common in children than adults and as a result the childhood programme aims to control influenza better by both protecting the children themselves, but also by reducing transmission across the population," he said.