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A Short History of Measles and Vaccine Hesitancy

The graphs accompanying this article show that vaccination rates have risen over the last ten years in California, while declining in most of the rest of the country. The California increase in vax rates correlates with the aftermath of the 2014 Disneyland Measles Outbreak, which caused over 300 measles infections, mostly in Southern California and Canada, and overwhelmingly among unvaccinated individuals. It also sparked debate on vaccine hesitancy and led to California Senate Bill 277, which revoked the “personal belief” exemption, thus tightening the rules around vaccination requirements for K12 public school children by eliminating nonmedical exemptions.

SB 277 was co-authored by Senators Richard Pan (who was a physician) and Ben Allen. At the time, some California public schools had vaccination rates below 60%, even though a 95% rate is required for Community Immunity (herd immunity) for many diseases, including measles. Though the bill was supported by the California Medical Association, the American Academy of Pediatrics, the PTA and California Children’s Hospital Association, there was loud and aggressive opposition by a tiny number of anti-vax activists, who tried (but failed) to get Pan recalled. They also called him a Nazi and made death threats against both him and Allen.

It takes a serious level of fear and anger to want to kill someone. So, what was driving this fear and anger?

A major factor is the false belief that vaccines cause autism. For new parents, autism can be a terrifying diagnosis. So, if there is any evidence that something specifically is causing autism, it makes perfect sense to try and avoid it. And if parents believed that the state was imposing an autism-causing drug on their children, it is not hard to see why they’d associate the law-makers with Nazis, and the drug with Zyklon B. To a rational, educated person who understands that the risks associated with vaccines are actually miniscule compared with the risks associated with the diseases they protect against, this kind of thinking by anti-vaxxers probably seems absurd, or ignorant. However, it’s not just an issue of education versus ignorance. Consider that Marin County, California, one of the nation’s most affluent and highly educated communities, once had one of the lowest vaccination rates in the state.

One reason people have associated vaccines with autism stems from the common mistake of conflating causation with correlation. Autism is often diagnosed in children around the age of two, which is around the same age that many childhood vaccinations are given. Many parents of autistic children got their diagnoses within a year or so of their children’s vaccinations and they made the assumption that the two were connected when, in actuality, it was a coincidence. Dozens of peer-reviewed studies have confirmed that there is no increased risk of autism due to vaccinations.

The belief that vaccines caused autism really took off in the late 1990s. After British physician Andrew Wakefield published his fraudulent 1998 Lancet article, falsely showing a link between the MMR (Measle, Mumps, Rubella) vaccine and autism, there was a sharp decline in vaccination uptake. However, other researchers were unable to replicate Wakefield’s results (something that should be easy to do if the study was valid). Additionally, journalist Brian Deer discovered that Wakefield had a significant conflict of interest because he stood to earn up to $43 million per year selling test kits. And the British General Medical Council (GMC) later found that Wakefield was guilty of mistreating developmentally delayed children.

When Wakefield’s study was discovered to be fraudulent, Lancet retracted his paper and the GMC revoked his medical license. In 2004, he moved to the U.S., where he continued to push his bogus anti-vaccination claims, directing the pseudoscience propaganda film “Vaxed.” Robert De Niro, whose son is on the autism spectrum, removed the film from the Tribeca Film Festival. However, proponents of the vaccines-cause-autism hypothesis, including U.S. Health & Human Services boss Robert F. Kennedy Jr., continue to push this lie. For a while, they tried to blame thimerosal, a mercury-containing preservative that was used in vaccines since the 1930s. However, in 1999, thimerosal was pulled from vaccines as a precautionary measure. And, guess what: autism rates continued to climb anyway.

Today’s measles outbreak is currently close to 300 cases, primarily in Texas and New Mexico, but with cases spreading to Oklahoma and other states. And nearly every one of those cases is in an unvaccinated patient. There have also been two deaths, one in Texas and one in New Mexico. However, in the U.S., measles mortality is general around 1-2 deaths per 1,000 cases. Because measles, unlike Covid and Influenza, does not mutate rapidly, this is unlikely due to the evolution of a more virulent strain. Rather, the nearly 300 documented cases today are likely a gross undercount. The actual number may be closer to 500 or even 1,000. And we may not even be at the peak yet, particularly considering how low the vaccination rates currently are.

Back in 2015, when the California’s vaccination rates were lower, and its legislature was considering SB 277, one of the public faces of the debate was a 6-year-old Marin County boy with leukemia, named Rhett Krawitt. His parents argued that it was not safe for him to attend school with unvaccinated children, since he was immune-compromised and at increased risk of contracting a deadly disease from them. At the time, 20% of Marin’s students had opted out of the required vaccinations. Rhett, himself, spoke to the school board, as well as the state legislature, contributing to Marin County’s shift from being one of the lowest vaccinated counties in California, to one of the highest.