Senior health officials have rejected claims made by Gerard Rennick that Covid-19 vaccinations amount to “experimenting” on children after the Liberal senator questioned the safety of the vaccine for children aged five to 11 in a Senate inquiry.
It comes after Rennick posted anti-vaccine content on Facebook making similar claims.
At a fiery hearing on Tuesday, the head of the Therapeutic Goods Administration, John Skerritt, rejected suggestions it was “nothing much” for children to catch Covid-19 and warned that misinformation was hindering its work.
The chair of the Senate Covid-19 committee, Labor’s Katy Gallagher, urged Rennick to “talk to a few parents whose children have struggled to breathe with Covid”, suggesting he “give [her] a call” – in reference to her daughter’s struggle with the illness.
On Sunday the TGA gave provisional approval for a one-third dose of Pfizer’s Covid-19 vaccine to be used in children aged five to 11, who will be added to the rollout from 10 January after a recommendation from the Australian Technical Advisory Group on Immunisation.
Rennick, who has extensively shared accounts of alleged vaccine adverse events on Facebook that he admits he can’t be sure are “100% accurate”, responded on his page that the TGA approval was “completely irresponsible”.
He claimed there were “serious concerns” about the sample size of clinical trials, citing an essay by a doctor of political economy with two years of statistical training who does not have expertise in epidemiology or vaccines.
On Tuesday the chief medical officer, Paul Kelly, reiterated that Pfizer is “worthwhile, safe and effective” for children aged five to 11.
Kelly said that Australian authorities had received “very reassuring” results from the US Centre for Disease Control, after 5m doses had been administered to children in that age group in the US.
These resulted in “vaccine side effects, which generally are very minor and not unexpected”, he said.
Kelly said the most concerning side effect was myocarditis or pericarditis, inflammation of the heart or the surrounding of the heart. These were an “extremely rare event” in children – with just four cases after 5m doses had been administered – but had been “amplified … by the misinformation campaign” online, he said.
He noted there had been 22,000 Covid cases this year in children aged five to 11 and although “only a very small number” have been hospitalised (1.4%) it was “not a trivial infection”.
Kelly cited disruption to children’s schooling and transmission by children with Covid to others. Skerritt added that one in 3,000 children develop multi-system inflammatory syndrome, which is “quite serious and lasts many months”.
“I reject the assertion that it’s nothing much for kids and doesn’t matter if they catch [Covid],” Skerritt said.
Dr Christopher Blyth, a paediatric infectious disease expert on Atagi, accepted that the “risk benefit” calculation is different in children because Covid tends to be less severe.
He accepted that 1,500 sample size for children in clinical trials was “low”, but said there was now a large dataset that would inform its advice.
“Do I have significant safety concerns? No I do not,” he said, adding that Atagi would continue to monitor results closely.
Both Skerritt and Blyth rejected Rennick’s suggestion this amounted to “experimenting” on children.
“That is not an experiment, that is using data to inform the rollout of a program,” Blyth said of using international data from the US. “We don’t have the capacity to wait for seven years for data in the setting of a pandemic.”
Skerritt rejected Rennick’s claim it takes seven to 10 years for full clinical trials of other drugs, and said the duration of two-and-a-half months for children’s Covid vaccines was “not all that different” from normal timeframes.
Rennick challenged witnesses about alleged unrecorded adverse events. Skerritt replied that the TGA only accepted such reports if experts agreed that evidence establishes on the balance of probabilities that the vaccine had in fact caused the side-effect because there is “no other likely cause”.
“If there isn’t cause and effect, it’s not a side-effect of the vaccine,” he said.
Gallagher told Rennick it was “not becoming of a member of the government to run the lines you’ve been running in this hearing”.
“You’ve got responsibilities you’re not observing,” she said.
Rennick replied that he was “merely putting forward the views” of those who had reported adverse events and “don’t want their children vaccinated”.
The Australian Medical Association vice-president, Chris Moy, told Guardian Australia that Rennick’s surveys of adverse events were “as far away from science as possible” because they “force one answer he wants”.
He said Rennick sought to “portray himself as a Robin Hood figure while inciting distrust and fear … against the scientists and health professionals who have done so much to protect Australia”.
“It’s not a fair fight because the vaccines that have been successful protecting us can’t stand up for themselves, the people would never know [that without it they would have got sick].”
Rennick told Guardian Australia he does not intend to stop social media advocacy on adverse events and rejected the label of misinformation.
“These are people’s stories and [the charge of misinformation is] an insult to those people,” he said. “It’s medical gaslighting of people who are having trouble getting their adverse events recognised.
“I’m not going to deny children having Covid is a bad thing … but don’t belittle others whose children have had adverse events.”
On Facebook, Rennick said he “definitely won’t be supporting any government legislation” until the approval for children was reversed. “The government has crossed the rubicon.”