Cartwright and his wife Shanelle have not vaccinated their children. Earlier in the week she said their kids were completely healthy and the "proof is in the pudding".
On Saturday, Shanelle took to Instagram again to complain about footy players being forced to accept a flu shot in order to play. She posted a screenshot of an article about the Titans stars being stood down, then wrote her concerns over the top of the image.
"According to the Australian immunisation handbook under 2.1.3 Valid Consent …" she wrote.
"2. It must be given voluntarily in the absence of undue pressure, coercion or manipulation.
"This is exactly that. We're entering very scary territory."
Cartwright, meanwhile, said he is not "anti-vaccinations" but stands "for the freedom to choose what goes into our bodies". He also said he won't be "bullied" into making decisions about his and his family's health.
Medical professionals have advised players to accept the flu shot because getting the flu and also coronavirus will be more detrimental to a person's health.
MORE STARS SPEAK UP
It was reported between 10-20 players initially refused the flu shot during the week and Manly star Dylan Walker has gone public with his concerns about mandatory vaccinations., issuing a lengthy statement on Instagram.
Walker's post was "liked" by North Queensland and New Zealand centre Esan Marsters.
ANTI-VAXXERS NEED TO TAKE ONE FOR THE TEAM
Sharks and NSW Origin star Wade Graham believes unless players are rejecting the flu shot on religious grounds, then it is a "no-brainer" to receive the vaccination to ensure the season stands a greater chance of restarting.
"If it's their personal preference that they don't have the flu shots, for me that's a no-brainer," Graham said on Triple M. "If they were in my team I'd be asking them to get the flu shot done.
"It's a team sport, right. So you do things that are not your personal preference a lot of the time and for me this is simple. Get the shot done so your teammates can get to playing.
"A lot of people have worked hard to get us in this position to give us an opportunity and for something as simple as this, for me it's a no-brainer.
"If it comes down to a personal preference this is one of the times where you're probably going to have to go against your personal preference."
Asked by rugby league journalist Paul Kent whether players who reject the jab should be stood down so the season can continue without them, Graham said: "If that's their choice, you're putting yourself into a corner there if you're not jumping on board.
"Even if I didn't like a flu jab, if it puts my livelihood at risk, preventing me from making some money to feed my family, then I'm getting a flu jab.
"It's simple in my eyes but it depends how strong the players' convictions are on an individual level.
"If they want to sacrifice their rugby league game for their personal preference not to get a flu shot, well that's their prerogative."
