The vast majority of Ontario students have been inoculated against highly contagious diseases like measles, mumps and whooping cough, but that still falls short of the “very ambitious” immunization coverage goal of 99 per cent for many vaccines, a new report shows.

The June report from Public Health Ontario looked at vaccination records for more than 1.5 million students aged 7, 12, 13 and 17 over three school years, starting in 2013-14. The data from 36 public health units on 14 publicly-funded immunization programs shows that immunization coverage “varies greatly” based on the vaccine program, geographic region and age group.

For the most part, the numbers show there is “strong support” for immunization across Ontario, one of the authors of the report, Dr. Sarah Wilson, told CTVNews.ca in a telephone interview.

Dr. Wilson, an epidemiologist with Public Health Ontario, highlighted immunization against measles as an example. In the 2015-16 school year, 92 per cent of seven-year-olds and 95 per cent of 17-year-olds had up-to-date immunization coverage.

“I think those (numbers) are evidence of good uptake of the measles vaccine and I think a lot of jurisdictions would be quite happy to have those figures,” Dr. Wilson said.

The report does note, however, that the provincial measles coverage failed to meet the “very ambitious, nationally defined coverage” of 99 per cent. That’s also the case for most other provincial vaccination programs, which have what Dr. Wilson also described as “incredibly ambitious” targets.

Still, the key takeaway from the report, she said, is that “the overwhelming majority of people in Ontario do support immunization.”

Dr. Wilson said that a couple of years ago, Public Health Ontario tallied the number of students across the province who had been granted immunization exemptions, based on religious beliefs or what’s referred to as a “statement of conscience.” The figure was “very low” at just below two per cent, she said.

Other highlights from the latest immunization report include:

Increasing vaccination against meningococcal disease.  Invasive meningococcal disease (IMD) is a rare, but serious illness that, in severe cases, can lead to delirium, coma, and death. Ontario’s meningococcal C conjugate vaccine (MCC) program provides one dose to toddlers at 12 months of age. The report shows that the rate of seven-year-olds who have received the MCC vaccine rose from 84 per cent in 2013-14 to 92 per cent in 2015-16.

Hepatitis B vaccination below national coverage goal. The report found that Ontario is currently below the national coverage goal of 95 per cent for universal hepatitis B vaccination programs. Across the three school years assessed in the report, approximately 84 per cent of students received at least one dose of the hepatitis B vaccine, and approximately 85 per cent completed the vaccine series.The report does note that the complete picture may not have been captured in the data due to differences in how the inoculation was tracked in previous years, and the fact that many students will still receive doses of the vaccine in the future. 

HPV vaccination rates need improvement. In the 2015-16 school year, 61 per cent of 13-year-old female students had up-to-date immunization against human papilloma virus (HPV), which has been linked to cancers of the cervix, anus and throat.

While that number is lower than other vaccine uptakes, Dr. Wilson pointed out that across the three school years captured in the report, 71 per cent of 13-year-old girls had received at least one dose of the HPV vaccine. And more than 84 per cent of those who started the HPV vaccine series completed them by the end of the school year.

Dr. Wilson said she is “optimistic” that changes to the publicly-funded HPV vaccine program, which has since been extended to boys, with the first doses administered in Grade 7, will improve the immunization coverage rates.

Dr. Allison McGeer, director of infection control at Toronto's Mount Sinai Hospital, said she was really pleased to see comprehensive immunization data in the latest Public Health Ontario report.

“We just haven’t had good data in the past,” she told CTVNews.ca in a telephone interview.

Dr. McGeer said the report will help address gaps in the publicly-funded immunization programs.

“The fact that we’re not on target for lots of things, it’s not an acute concern but it’s a message for all of us that we really need to be focused on maintaining and improving vaccine programs,” she said.

“Although things are pretty good, there’s still room to improve.”