"The flu vaccine is not going to protect you directly against the coronavirus," Dr Kidd told AAP.
"The (flu) vaccine is a very specialised vaccine for giving protection against four strains of flu and that changes every year."
Dr Kidd also warned people away from hydroxychloroquine, an ingredient in arthritis treatments and malaria vaccines, which had been promoted as a possible cure for coronavirus.
"It's a very small amount that's an overdose and kills people - it's quite dangerous," he said.
'Rationality goes out the window'
Dr Kidd has seen all sorts of scams claiming a cure for COVID-19, like alternative medicines, vibration therapy and even crystals.
"It's a worrying time because when people get panicky as we've seen, rationality goes out the window," he said.
"We all need to be very, very careful now. And the last thing we need to do is be spending a lot of money fruitlessly on a scam."
Dr Kidd said the best way to keep safe was to practice the social distancing and hygiene measures recommended by the government.
"I would prefer to call it physical distancing," he said.
"It's about just maintaining that safe physical distance. Some people refer to it as protecting your personal space."
No more than two people will be allowed to meet in public or private under new guidelines announced by the government.
Dr Kidd said people should only be going out to buy essential goods, keeping 1.5 metres from people, sneezing or coughing into their elbow, and staying home if they feel sick.
There are more than 4000 confirmed cases of coronavirus in Australia, with 17 people dying.