Measles and an Outbreak of Science Illiteracy

On January 22, the World Health Organization declared anti-vaxxers a “Top Threat to Global Health in 2019.” The agency specified “ vaccine hesitancy” as the “reluctance or refusal to vaccinate despite the availability.” It’s the first time that vaccines have made the agency’s list of the top ten biggest threats to global health.

Might it be time for President Trump to stop tweeting about the long-defunct link between vaccines and autism?

An Almost-Vanquished Childhood Disease

I had the measles when I was four, with its characteristic fever and spots, for an entire month. My sister got a vaccine. She shrieked at the two shots, but she became a teacher so I think in retrospect she’d agree it was worth it.

Before the measles vaccine became available in 1963, epidemics in the US cycled every 2 or 3 years, with 3 to 4 million cases a year, and on average 450 deaths. Before that time, half or more of an elementary school classroom could be vacant as the highly contagious disease swept through. Nearly everyone had had measles by age 15.

Measles was eliminated from the U.S. in 2000. But now it’s back. This week the CDC reports outbreaks in 10 states, with 101 cases already for 2019. And it’s only February.

The recent history of the resurgence keeps circling back to “unvaccinated people,” in CDC parlance. A few cases popped up in the US in 2008. The scattered outbreaks ever since have often been traced to travelers returning to the US, and then the infection ricocheting through communities via the unvaccinated.

Those who choose to avoid vaccination shatter the safety net of herd immunity: vaccinate enough members of a population, and an infectious disease won’t spread.

But so many people just don’t get that, and/or can’t see beyond their own desire to protect their children from a needle stick and fear of a time-tried technique. At least now some teens are educating themselves and overruling their parents’ ignorance and getting vaccinated.

Creeping Back

2019 seems poised to become the year that measles returns, thanks to the anti-vaxxers. Different groups are guilty of avoiding vaccination.

In 2018, 82 people brought in measles from other countries, with a large cluster among Orthodox Jewish communities in the New York City area that began with travelers returning from Israel.

In 2017, 75 cases in Minnesota came from a Somali-American community with unvaccinated members.

In 2015, epidemiologists traced 147 cases to a California amusement park, an outbreak thought to have originated from a traveler returning from the Philippines, because the strain matched that from an outbreak there the year before.

In 2014 the U.S. had 23 outbreaks, including one of 383 cases, mostly in unvaccinated Amish communities in Ohio and lingering cases from the Philippines. Earlier cases came from Europe, mostly France.

I’ve covered vaccine success stories for several publications, including here at DNA Science: Vaccine Memories: From Polio to Autism and Remembering The Pre-Vaccine Era: The Diseases of Childhood. When I wrote A Necessary Retelling of the Smallpox Vaccine Story here in early 2017, I really didn’t think I’d need to rerun it. Surely by now the public would have grasped the logic of herd immunity that requires no specialized knowledge.

I was wrong.

So, here, again, two highlights from the history of vaccine technology: Andrew Wakefield and Edward Jenner. But first, a refresher.

Vaccines 101

A vaccine is a pathogen, or part of one, whose presence in a human body evokes an immune response, yet it isn’t complete or active enough to transmit the illness. When the vaccinated person encounters the wild pathogen, the protective antibody response is immediate, thanks to immune memory.

Vaccines aren’t just biomedicine, but bioethics too. The herd immunity that arises at the population level protects us all, illustrating the principle of beneficence: action for the benefit of others. Vaccinate enough people against a particular pathogen, and it can’t find enough sensitive people to rampage through a population.

In plain English, when parents refuse to vaccinate their children, other children can die. Yet vaccines are not entirely risk-free; no medical treatment or procedure is. Most reactions are due to allergy or the necessary revving up of the immune response.

The Discredited Dr. Wakefield

The vaccine-autism link arose from a paper published in The Lancet in 1998, in which English physician Andrew Wakefield described “a pervasive developmental disorder” in 12 children. The large, red word “RETRACTED” appears on the first page.

The study had no controls and a tiny sample, but case reports are ok in the medical literature given appropriate caveats. What wasn’t ok (among many other problems) was that attorneys representing allegedly harmed children were paying Dr. Wakefield to make his claims. When this news surfaced, The Lancet, in February 2010, again fully retracted the paper — in case anyone missed the earlier discrediting. Apparently lots of people did. The “debate” persists among the uninformed.

Edward Jenner’s Story

Whenever I write about vaccines I retell the classic story of Edward Jenner and his testing of the smallpox vaccine that has rid the world of this terrible disease. The reasoning that led to this world-altering invention is both straightforward and brilliant.

Vaccine technology dates back to the eleventh century in China. Based on the observation that those who recovered from smallpox never got it again, people would collect the scabs of infected individuals and crush them into a powder, which they inhaled or rubbed into pricked skin.

In 1796, the wife of a British ambassador to Turkey witnessed the Chinese method of vaccination, and mentioned it to an English country physician, Edward Jenner. Intrigued, Jenner had himself vaccinated the Chinese way, and then thought of a different approach.

It was widely known that people who milked cows contracted a mild illness called cowpox, but didn’t get smallpox. The cows became ill from infected horses. Since the virus seemed to jump species, Jenner wondered, would exposing a healthy person to cowpox lesions protect against smallpox?

Wrote Jenner of the horse ailment that farmers transferred to cows: ‘It is an inflammation and swelling in the heel, from which issues matter possessing properties of very peculiar kind, which seems capable of generating a disease in the human body … which bears so strong a resemblance to the smallpox that I think it highly probably it may be the source of the disease.’

A slightly different virus causes cowpox than smallpox, but Jenner’s approach would prove successful, leading to development of the first vaccine (from the Latin vaca for “cow”).

Unable to experiment on himself because he’d already taken the Chinese vaccine, Jenner instead tried his first vaccine on 8-year-old James Phipps. On May 14, 1796, he dipped a needle in pus oozing from a small sore on a milkmaid named Sarah Nelmes, then scratched the boy’s arm with it.

Young James survived, and the smallpox vaccine was born. Eventually, the vaccine would completely eradicate the disease, although several nations maintain the virus in storage for research purposes.

Just as I was one of the last kids to have measles, I was also one of the last to have a smallpox vaccine. My kids didn’t need it, because the last case of smallpox in the world, in Somalia, was in 1977.

My smallpox vaccine left a telltale scar on my upper left arm. I regard it as a badge proclaiming the genius of this public health tool that is still, sadly, so misunderstood.