Federal Health Minister Greg Hunt is in hospital suffering from a suspected infection, although his condition is not believed to be linked to getting a COVID-19 jab.
The 55-year-old Victorian Liberal MP is being kept overnight for observation and will take antibiotics and fluid while in hospital.
The minister's office says he is expected to make a full recovery.
Alongside former prime minister Julia Gillard and Department of Health secretary Brendan Murphy, the Liberal MP was among the first to receive the AstraZeneca jab at a Melbourne clinic on Sunday.
At the time, Mr Hunt said vaccinations safeguard the community from more than just coronavirus.
"Whether it's smallpox, measles, mumps, rubella, whooping cough, influenza, and now COVID-19, vaccinations can save lives and protect lives," he told reporters.
Mr Hunt, elected to the seat of Flinders on Victoria's Mornington Peninsula almost 20 years ago, has been overseeing Australia's medical response to the coronavirus pandemic.
He was appointed to the Health Minister portfolio in 2017 by then-prime minister Malcolm Turnbull.
His hospitalisation comes as fellow federal ministers Christian Porter and Linda Reynolds are away on leave amid separate rape allegation scandals.
Victorian Premier Daniel Andrews was also admitted to hospital on Tuesday after suffering broken ribs and damaged vertebrae in a fall.
