Victoria's Juries Commissioner was granted the right to ask people called for jury service for proof of vaccination under amended legislation that passed state parliament on Thursday.

It gives the commissioner power to defer a person from serving on a jury for health, safety or welfare reasons including their COVID-19 vaccination status.

Those unable to prove they're vaccinated may be deferred. It applies until 2022.

"Vaccinations are our strongest weapon against the virus - this amendment gives courts an extra measure to make our courts as safe as possible, helping to quickly get jury trials back underway," Attorney-General Jaclyn Symes said.

The passage of the amendment came hours after a Victorian County Court Judge ruled he didn't have the authorisation to ask jurors their vaccination status.

Defence lawyers in a criminal trial, due to take place in regional Victoria, asked the judge to question jurors about their vaccination status "with a view to facilitating a double vaccinated jury".

Alternatively they wanted to be able to challenge each potential juror on the basis that their vaccination status was unknown.

The judge, who cannot be identified, ruled against both requests.

They said there was nothing giving them authority to ask such questions and the proposed challenge wouldn't be valid.

Defence lawyers appealed that decision to Victoria's Court of Appeal where the matter is listed for Friday morning.

Australian Associated Press