Dr. J. Edward Les, MD, is a Calgary Pediatrician and a Senior Fellow with the Aristotle Foundation for Public Policy.It’s fall, which means for many Canadians it’s vaccine season. But opposition to vaccines stands in the way of their administration, driven in part by politics south of the border.Back in August, US President Donald Trump signed an executive order aiming to overhaul immunizations for American children, specifically by removing universal recommendations for vaccinations against entities such as meningococcal disease, hepatitis B, and influenza — thereby reducing the number of infectious diseases against which children would be protected from 17 to 11.The rationale for this change, apparently, is to reduce the challenge to children’s immune systems. "Large amounts of vaccine,” the President remarked, “… like vats of vaccine are currently pumped into your child's body.” Reality check: The fact is that doctors administer less than 0.5 mL per vaccine — usually 0.1 to 0.3 mL per vaccine. A teaspoon, by comparison, is about 5 mL.And it’s important to emphasize that while all vaccines contain antigens (small molecules that trigger an immune response in the body — training the immune system is the point, after all), small children are exposed to somewhere between 2,000 and 6,000 antigens every day, while the entire pediatric immunization schedule (before the recommended revision) exposes a child to approximately 165 antigens. Multiple vaccines — including multiple vaccines in one shot — do not overwhelm a child’s immune system but rather train it to respond ably to infectious threats.Which brings me to perhaps the most startling new recommendation: that the MMR (measles, mumps, and rubella) vaccine be divided into three distinct immunizations to be given at separate visits..The MMR vaccine has been in use for 55 years in the US and is administered in well over 100 countries around the world; it’s hugely effective and has an impeccable safety record (it’s not "lethal" as the President suggested). There is no scientific basis for splitting the vaccine into separate injections, and the inconvenience of three visits (and, for American families, the increased cost) will inevitably drive immunization rates lower.That said, the factor that, more than any other, is sure to drive immunization rates lower — it has already done so — is the ongoing public musings by the President and by his Secretary of Health and Human Services, Robert F. Kennedy Jr., that childhood vaccines are responsible for rising rates of autism. While it’s certainly laudable to pursue the root causes of autism, there is no evidence that implicates vaccines as the culprit, despite exhaustive studies examining the issue.Which is not to suggest that those studies are perfect; few, if any, scientific studies are. Scientific evidence, by and large, is imperfect; studies can be contaminated by biases, industry influences, and improper conclusions reached due to incomplete data collection, confounders, false correlations, and so on. But researchers and physicians mostly do the best they can, fully cognizant of these imperfections and of the reality that science is never “settled.” They constantly sift and challenge the data as it’s generated and presented, in a never-ceasing effort to get to the truth.There’s no “conspiracy” on the part of doctors to inflict vaccinations on children. By the curious illogic of those opposed to vaccines, the implicit assumption is that scientists secretly concoct deadly poisons and then inject themselves and their families with them. Those skeptical of childhood vaccines should reflect on such assumptions.Of note, in the early 1990s, in response to reports linking the mumps component (a different strain from the one used in the US) to rare cases of meningitis, Japan withdrew its MMR vaccine from the market, and the country pivoted to individual vaccines, with mumps vaccination left as optional. Mumps immunization rates promptly plummeted, and deafness in children caused by mumps infection doubled. Now, more than 30 years later, Japan has again licensed a three-in-one MMR vaccine, this time with a different mumps strain.It’s no accident, in the face of declining immunization rates, that measles has staged a comeback both in the US and Canada. Measles, while it’s not polio or smallpox, is more than “just a rash.” As we are seeing in Pennsylvania currently, it hospitalizes up to 20% of its victims, and it has the capacity to kill — five people have already died this year in Pennsylvania because of measles..Measles also damages existing immunity to other viruses (so-called “immune amnesia”), leaving kids vulnerable to other infections for months; in rare cases, it can lead to fatal encephalitis (subacute sclerosing panencephalitis). Mr. Kennedy’s public response to the recurrence of measles has been rather confusing: on the one hand, he’s on record as saying he would not give his kids, if they were young right now, the measles vaccine, while on the other hand, he proclaims that children should get the measles vaccine for protection.By the time of MMR’s insertion into the routine childhood immunization schedule in 1971, deaths from measles had already significantly declined thanks to improved childhood nutrition, modern public sanitation systems, and advances in medical care.But it still killed 400 to 500 American children per year; the introduction of MMR relegated that to a historical footnote, and by 2000 America was declared free of measles. Worldwide, measles has continued to be a significant killer, with an annual death toll of roughly 95,000 per the World Health Organization, mostly amongst the unvaccinated.But now measles is back in force in America. Given its highly contagious nature, immunization rates of 95% or greater are needed to prevent its spread, and many jurisdictions have fallen well below that.And measles is the proverbial canary in a coal mine. As vaccination rates decline, other preventable infectious diseases — polio, diphtheria, tetanus, and so on — threaten to return. Relying on “natural immunity” (infection with disease and subsequent immunity) to protect our kids from those scourges of the past isn’t a wise approach when the cost is counted in the form of paralysis and death.One hopes that Mr. Trump will change course as the folly of his new vaccine policy becomes apparent. Reversing course can be difficult; it can be hard to admit to getting things wrong. Physicians and medical researchers know that perhaps better than anyone.But an honest approach to progress in science demands constant humility.Dr. J. Edward Les, MD, is a Calgary Pediatrician and a Senior Fellow with the Aristotle Foundation for Public Policy.
