A new outbreak of measles in the New York City area, among the largest in decades, shows how whole communities are put at risk when parents refuse to vaccinate their kids. Vaccines are only truly successful as a community effort – it’s not merely a personal choice, as many in the anti-vaccination movement, as well some politicians like Chris Christie and Rand Paul, have argued.
Measles, a disease the Centers for Disease Control declared eliminated by 2000, continued its comeback last year. In the US, the CDC reported 349 cases over the year. Globally, the disease spiked in 2017, with 6.7 million cases – a 30 percent increase from the year before, according to the World Health Organization. They attribute the rise to a combination of the growing anti-vaccine movement, and social instability.
Scientists warn that measles is a “canary in the coal mine” for the rise of other preventable diseases. It’s highly contagious – unvaccinated people have a 90 percent likelihood of contracting the disease if they are within a confined space with an infected individual who coughs or sneezes. Unlike other viruses, it can survive as long as two hours in the air. It is contagious for four days before the appearance of a rash, and for four days afterwards. One person with measles can infect as many as 12 to 18 other people.
And the disease can be fatal, having killed 110,000 in 2017. About 1 in 3 people who contract measles will experience complications, which can include pneumonia, swelling of the brain, and death.
“Herd immunity” means that a certain percentage of any population needs to be immunized for a vaccine to be truly effective. If a given percentage of a population is immunized, it makes it very hard for a certain disease to spread. For the MMR (Measles, mumps, rubella) vaccine, 95 percent of a population needs to be vaccinated. This is called the critical immunization threshold.
About half of the US measles cases in 2018 were in New York, with 55 cases in Brooklyn and 108 cases in nearby Rockland county. These cases are concentrated within the area’s small, and tightly-knit communities of Orthodox Jews, where city health officials have also noted the spread of anti-vaccination propaganda.
The Brooklyn-based Parents Teaching and Advocating for Children’s Health (PEACH) was leading the charge, citing a local rabbi that had been promoting the popular, yet debunked, claim that the MMR vaccine leads to autism in children.
Many of the cases involved small children between the ages of seven months and four years, long before they enter school and their parents are required to show evidence they have been vaccinated.
Past outbreaks of measles have also centered around small, closely-intertwined communities where anti-vaccination sentiment has taken hold. In 2017, Minnesota saw its largest measles outbreak in three decades, in which 80 percent of cases involved Somali-American families that had been targeted by anti-vaccination literature, according to Minnesota’s health department.
In 2014, the US had its worst year for measles in decades, with 644 cases. Nearly 400 of those cases were in Ohio, where many Amish had started refusing vaccines after two children allegedly became sick after getting the vaccine. Notably, the refusals were not for religious reasons, but because the notion had recently spread that vaccines were harmful. When a missionary returned from the Philippines with measles that year, there was nothing to stop it from spreading rapidly through the increasingly unvaccinated community.
In these small groups, it doesn’t take much for the percentage of vaccinated people to drop below the critical immunization threshold. And when one member brings measles into the community, the damage can be immense.
These outbreaks among smaller populations should serve as a cautionary tale on what could happen if a higher percentage of the wider population were to start refusing vaccines. Immunization rates remain high, but the percentage of children under two years old not receiving vaccinations has quadrupled since 2001 – a trend that will become dangerous if it continues.
According to the New York City Health Department, there’s been a substantial uptick in child vaccination there since the outbreak. It’s been generations since we’ve seen diseases like measles at their worst and most widespread. Before 1963, when the vaccine was approved, it’s estimated that there were 3 to 4 million cases in the US each year, with up to 500 deaths and 48,000 hospitalizations.
With these large-scale outbreaks fading from memory, it’s easy to forget how important vaccines really are. These local communities are learning hard lessons from their experiments with vaccine refusal. It’s imperative that the rest of the country learn these lessons as well, without even larger outbreaks needed to make the point.