Pediatricians fear possible slide in vaccines may compromise herd immunity
TORONTO
Pediatricians are urging parents to maintain their children’s vaccination schedule amid the COVID-19 scare, cautioning that even a slight dip in inoculation rates could jeopardize herd immunity for a host of other ailments.
Many children and young people are almost certainly behind on their shots as infection fears push some families to avoid medical facilities, says Dr. Shaun Morris, staff physician in infectious diseases at Toronto’s SickKids Hospital.
At the same time, opportunities to inoculate have dwindled as family clinics scale down hours, switch to virtual care or shutter their offices completely. Meanwhile, school-based immunization clinics have been postponed indefinitely.
In provinces that require proof of vaccination to attend daycare and school, the closures remove one of the most powerful motivators parents have to keep their kids up-to-date, says a spokeswoman for the Canadian Paediatric Society.
Dr. Joan Robinson wonders if daycare and school closures could disrupt vaccine adherence even more than the vaccine hesitancy of families who question their safety.
“The most common reason Canadian children are not immunized is simply because the parents never got around to it,” says Robinson, also a pediatric infectious diseases specialist in Edmonton.
“And that’s not necessarily being critical of the parent. Many people have a very hectic kind of life — they maybe don’t have a car, they’re living in a not-great situation, so taking their 18-month-old for immunizations is pretty low down on the priority list.”
It’s only been about a month since most Canadians adopted strict physical distancing measures so Morris says we haven’t yet seen whether vaccination rates will change significantly. But he’s wary of the possibility, noting rates dipped in West Africa during the Ebola crisis, resulting in a spike of measles cases there.
“Myself as well as my research colleagues are in the process right now of thinking of how we can study this exact question to try to quantify it, to try to understand what reasons may be behind a decrease in immunization, and also importantly (what happens) downstream if it’s related to an increase in vaccine-preventable diseases,” says Morris.
Most physicians who have paused their work are referring patients to another doctor or pediatrician if needed, he says, but pandemics in general give rise to a whole host of factors that can derail routine care.
Ontario’s school closures, for instance, have delayed school-based immunizations delivered by local public health units “until further notice,” according to an email Tuesday from a health ministry spokeswoman.
Under normal circumstances, spring clinics would be underway right now to deliver the meningococcal conjugate, human papillomavirus (HPV) and hepatitis B vaccines to Grade 7 kids. Kids aged 14 to 16 are also required to get the threein-one tetanus, diphtheria and pertussis ( Tdap) vaccine under the province’s Immunization of School Pupils Act.
The ministry said the closures themselves “help protect students until schoolbased immunizations resume” but there was no indication on when that might be.
Like Ontario, New Brunswick requires proof of up-to-date vaccinations for kids at daycare and school unless they are exempted for medical reasons or parental objection, while British Columbia requires parents to provide immunization records for enrolled students.
Broadly speaking, Robinson says there’s more leeway for older children to push their immunization schedule, so it’s safe for tweens and teens to delay their shots until classes resume. She adds that public health would likely make accommodations if the closures extend for a long time.
It’s a different story for the primary series of vaccines given to infants at two-, four-, six- and 12-months-old - those should “absolutely not” be delayed, says Robinson.
Robinson stresses the importance of infant vaccines that prevent bacterial meningitis, which is more common and more serious in young children than in older children.
“It gets super-important to not delay those immunizations, no matter what,” says Robinson, who works at Stollery Children’s Hospital.
Even the 18-month-old shot, which is meant to boost immunity to vaccines the child already has, should be given on time if possible, she advises.
The preschool immunization should ideally be given at age four but can be delayed until age 6, “if parents really want to,” she adds.
Vaccinating children does more than protect the child - it can also protect adults who can be infected by children.