New Brunswick's education minister has delivered a scathing critique of anti-vaccination activists at the start of three days of public hearings on a tough new law he's proposing.

Dominic Cardy told a committee of MLAs that opponents of vaccination are conspiracy theorists who "influence, mislead and deceive" parents into thinking their children are at risk if they are vaccinated.

"This is not supported in fact," Cardy said. "If you believe in evidence-based decision-making, you have to look at the evidence, and the evidence is incontrovertible."

He said growing anti-vaccination sentiment, spread by social media, risks reducing the percentage of vaccinated children below a critical threshold that allows the population as a whole to resist an outbreak.

"The anti-vaccination movement threatens kids and it threatens their lives," he said. "There are no two sides around the safety of vaccines."

'Two sides'

A leading anti-vaccination activist attending the hearings told reporters Cardy's criticisms were "disappointing."

"There's two sides to every story and anyone who thinks there's one side has an underlying motive for thinking so," said Dena Churchill, a former chiropractor from Halifax who lost her licence to practise because of her public campaign against vaccinations.

Churchill alleged that U.S., Canadian and Nova Scotia health agencies were deliberately covering up incriminating data about vaccines.

But she dodged questions from journalists about why governments would do that.

"I don't know what the motives are," she said. "I'm not a politician. I don't understand the political parties."

She also made claims that have been debunked by governments and experts about the presence of glyphosate, aluminum and mercury existing in vaccines at dangerous levels.

Dena Churchill, at right, an anti-vaccination activist attending the hearings called Cardy’s criticism 'disappointing.' (Jacques Poitras/CBC)

Health Canada calls vaccination "one of the world's greatest public health achievements, along with sanitation, antibiotics and clean drinking water" that has prevented diseases such as measles, mumps and polio for which there is no treatment or cure.

Cardy's bill would eliminate non-medical exemptions for children whose parents choose to not have them vaccinated. Those children would not be allowed to attend public schools and would have to resort to private schools or home schooling.

He told the committee he was working on the bill before two outbreaks earlier this year of measles in the Saint John area and whooping cough in the Fredericton area.

But those two outbreaks underscored the need for tougher legislation, Cardy said.

He said while he generally would not want to infringe on the freedoms of parents to choose, the risk to the broader school population makes it necessary.

Experts estimate that 95 per cent of a population must be immunized to achieve "herd immunity" — a critical mass that makes it unlikely the disease will be able to spread.

Because vaccines don't work in three per cent of cases, Cardy said, only two per cent can remain unimmunized without risk.

Unfounded beliefs

He said current statistics show 1.6 per cent of the school population have exemptions, some for legitimate medical reasons and some for other reasons. He wasn't able to say whether that number has been creeping up or how many of the exemptions were medical.

But he said the spread of unfounded anti-immunization beliefs online could lead to an increase, and that's why his bill is needed. No other province has as strict a policy, though some American states do.

Cardy said the importance of the vaccination bill was underscored by outbreaks of whooping cough and measles in two cities. (The Canadian Press)

A series of anti-vaccination activists are scheduled to testify during the three days of hearings. Cardy said normally, what he calls "fringe" opinions, such as claims the moon landings were faked, should not get that kind of a platform.

But the anti-vaccination movement needs a public debunking because of the health risk, he said.

Dr. Bob Sears, a California pediatrician who opposes mandatory vaccination, compared what he called the "police powers" in Cardy's bill to the racist "separate but equal" segregation of white and black children that existed in the U.S. South before the civil rights era.

He was taken to task by PC MLA Glen Savoie, who said it was offensive that a California physician was lecturing New Brunswick politicians on what to do.

Travel funded by anti-vaccination group

Savoie got Sears to admit his travel was funded by an anti-vaccination group. The Saint John East MLA said he still suffers from complications from chicken pox, German measles and red measles that he caught as a child because he wasn't vaccinated.

Sears also faced questions about being put on probation by the Medical Board of California over his intervention in a child custody case about vaccinations. Sears can practise medicine, but his files are monitored by another doctor.

New Brunswick Medical Society president Dr. Serge Melanson told the committee that vaccines go through rigorous reviews and are generally safe.

But he said because the numbers were so small, he couldn't say for sure whether the bill would have prevented this year's measles outbreak if it had been in effect.

"It's hard to say whether it would have had a significant impact or not. The answer might be no."

Cardy's bill will require the support of at least one other party in the legislature to pass because the Progressive Conservative government lacks a majority.

Cardy took questions from MLAs from all four parties in the legislature during his two-hour testimony. The Progressive Conservative government lacks a majority in the legislature, so at least one other party will have to support his legislation for it to pass.

Detailed questions

None of the MLAs from the three opposition parties spoke against his bill, instead asking questions about the details of how it will work and what alternatives he looked at.

He said education campaigns have proven not enough to change vaccination rates in other provinces. He also said it's not clear whether his bill would withstand a constitutional challenge because no such case has reached the Supreme Court of Canada.

Despite Cardy's aggressive attack on the legitimacy of anti-vaccination activists, PC Bruce Northrup, the MLA for Sussex-Fundy-St. Martins, said the committee would need to look at "both sides of the story."

"Sometimes there is the in-between," Northrup said. "We have to get to the facts as a committee."

Cardy would not say during a scrum with reporters whether all of his 21 fellow PC MLAs support his legislation.

The hearings continue on Wednesday.