Canada's top health professional says “campaigns that target parents on social media and the internet” are planting “seeds of doubt” about vaccines, and she's worried serious diseases are making a comeback. Dr. Theresa Tam, Canada’s chief public health officer, said in a statement Tuesday that she was heartbroken to see Canadian parents talking to media about losing their children to measles, a vaccine-preventable disease. “In an era where, thanks to the success of vaccines, we are no longer familiar with these dangerous illnesses, some parents have come to fear the prevention more than the disease,” said Tam, who is a physician with expertise in immunization.

“Seeds of doubt are often planted by misleading, or worse, entirely false information being spread in campaigns that target parents on social media and the internet. It is no wonder some parents are confused and concerned.” #Measles is highly contagious and not benign; at best it’s a miserable fever & head to toe rash. At worst complications can be serious and even permanent. Get up to date – Vaccinate! https://t.co/Ib49BqYTiJ pic.twitter.com/KKeHDhSMUD — Dr. Theresa Tam (@CPHO_Canada) February 26, 2019 So-called anti-vaxxers use social media to spread false information, with one popular claim being that vaccines cause autism. The proported link between the two is based on a fraudulent study that has since been withdrawn, and has also been debunked through scientific research.

Measles was declared eradicated in 1998 in Canada, but is starting to appear again. The disease can lead to permanent disabilities like blindness or brain damage, encephalitis that can cause seizures and in some cases death. The Public Health Agency of Canada said in a March 8 monitoring report that 19 cases of measles have been reported nationwide so far this year, largely in British Columbia. When the World Health Organization released its list of "10 threats to global health" in January, "vaccine hesitancy" made the list. Handout photo of Dr. Theresa Tam, Canada’s chief public health officer. Health Canada Photo "Vaccination is one of the most cost-effective ways of avoiding disease: it currently prevents two to three million deaths a year, and a further 1.5 million could be avoided if global coverage of vaccinations improved," it wrote. Tam said she was “very concerned” to see vaccine-preventable diseases “making a comeback in Canada” and vowed to work with partners in the months ahead “to continue to address the misinformation around vaccines.” She called on healthcare providers “to take the time to answer the questions of concerned parents.” She also urged parents and guardians to turn to “reliable sources of information” such as Immunize Canada, the Canadian Paediatric Society and her own agency.