The Federal Chief Medical Officer has urged increased mask wearing indoors and employers to allow work from home, amid a “significant” rise in cases of the new BA.4 and BA.5 subvariants of COVID-19.

Speaking at press conference alongside Health Minister Mark Butler on Tuesday, Professor Paul Kelly warned the public “we are at the start of a COVID wave not the end” with vaccination alone not effective in stopping the infection of transmission from person to person.

Professor Kelly urged everyone who is eligible for a third or fourth dose to make an appointment as soon as possible, saying two doses of the COVID vaccine was not enough to protect against severe disease.

“I also encourage everyone to follow the recent advice of the AHPPC (Australian Health Protection Principal Committee) and wear masks when outside the home in crowded, indoor environments, including on public transport. This is important to protect yourself and others,” he said.

“Physical distancing, where possible, and following good hygiene practices provide additional layers of protection. Undertake a test if you have any symptoms and stay at home if you have COVID-19.”

“We cannot stop this wave of infections, but we can slow the spread and protect the vulnerable,” he added.

“We have done this before, and we can do it again.”

It comes as the Therapeutic Goods Administration grants provisional approval for Moderna’s COVID-19 vaccine for children aged six months to five years of age.

However, Health Minister Mark Butler stressed supplies of a COVID vaccine for children are limited and would need final approval from the Australian Technical Advisory Group on Immunisation before the rollout could begin.

“I want to stress that there is very limited supply of this Moderna product, which is a different product to the products made available to other age cohorts,” he said.

“A very limited supply of this Moderna product across the world, and as you can imagine, there is fierce competition by countries in North America, Europe and other parts of the world to get their hands on this very limited supply.”