Defending vaccines and combating antiscience
This opinion article first appeared on April 29, 2019 in the Journal of Clinical Investigation and has been edited here for length.
The 2019 measles outbreaks across America may signal a new phase in the antivaccine movement. For the first time, antivaccine sentiments have mainstreamed to adversely and widely affect child health in the United States.
With many parents convinced that vaccines are dangerous, there are now more than 100 pockets of very low vaccine coverage in at least a dozen US states. Because of its high transmissibility, the measles virus is often the first to cause breakthrough childhood infections in such areas of vaccine refusal, especially among infants not old enough to receive their first vaccine dose. According to the CDC, 555 measles cases have been confirmed in 20 states in the first quarter of 2019, with the largest outbreaks so far occurring in Washington and Oregon (78 cases) and Texas (14 cases). In New York, more than 400 measles cases have been reported since the end of 2018.
These outbreaks are likely just the beginning: the CDC reports that at least 100,000 children in the United States are fully unvaccinated, while in Texas alone 76,000 parents requested “conscientious exemption affidavits” for their children in 2018, more than a 60 percent increase since 2014 and almost a 20 percent increase since the previous year.
We find ourselves in a deplorable situation in which infants and children are routinely and deliberately denied access to many of their vaccines, including measles-mumps-rubella (MMR) vaccinations, despite the strong recommendations to vaccinate from the CDC, its Advisory Committee on Immunization Practices (ACIP), and all of the major pediatric and academic societies.
Today, the antivaccine (sometimes referred to as “antivax” or “antivaxxer”) movement has evolved into its own media empire (Figure 1). One report indicates that there are now at least 480 antivaccine websites on the internet, which are amplified routinely on social media sites, especially Facebook and Twitter. Amazon is now the largest purveyor of antivax books, such that many of the top-selling books on vaccination are against vaccines. Not surprisingly, antivaccine misinformation is now pervasive to the point where it is difficult for parents to easily download accurate health information about vaccines.
The movement has also added a political dimension. Many states now host their own antivax political action committees (PACs) lobbying to enact legislation to make it easier for parents to exempt their children from mandatory school vaccines or to make it more difficult for schools to require vaccinations. Both the media and political elements of the antivaccine lobby have recently accelerated to a point where we can anticipate future measles outbreaks and declines in vaccinations against many other childhood infections, including influenza.
The antivaccine movement does not always speak with a single voice, and its rationale for objecting to vaccines or questioning their safety can vary. However, the most common reason cited by major antivax websites, social media sites, books sold through Amazon, and even a major documentary, is that vaccines cause childhood autism. In many cases the MMR vaccine is cited as the offending vaccine, but more recently it has been alleged that autism results from the thimerosal preservative that was previously in many childhood vaccines or from aluminum-containing adjuvants, or that somehow an infant’s fragile immune system is overwhelmed by administration of too many vaccines simultaneously.
As both a pediatrician-scientist who develops vaccines to prevent neglected tropical diseases (NTDs) and a parent of an adult daughter with autism, I spent months investigating possible vaccine-autism links, only to find massive evidence involving over one million children confirming no link between any vaccine and autism. The studies show that children who are vaccinated are no more likely to be on the autism spectrum than unvaccinated children, while children with an autism diagnosis are no more likely to have gotten vaccinated than children not on the autism spectrum.
I also point out how my daughter Rachel’s autism was not caused by vaccines, and there is no real plausibility of linking the two. Over the last two decades, we have learned a lot about autism and how it begins in early fetal development. In 2018, a large international collaboration led by the Broad Institute at Harvard-MIT found that autism genes are expressed early on in brain development (mostly in the neocortex) and are linked to neuronal communication or gene expression. They include genes encoding the neuronal cytoskeleton — through whole-exome sequencing done at Baylor Genetics, we think a similar gene may possibly be involved in Rachel’s autism.
Synthesizing the information that de-links vaccines from autism requires a strong scientific background, while conveying this message requires the interest and willingness to take the time to engage in public discussions. Unfortunately, health communication and messaging are still often neglected in most physician-scientist training programs.
Indeed in my MD/PhD training during the 1980s, we received a strong message that speaking with journalists or engaging in public discourse was not looked upon favorably and was even criticized or condemned. However, times have changed, and now the antivax and other antiscience movements have conquered the Internet and disseminate misinformation on a scale that far exceeds the accurate messaging from scientists. We therefore must look to new roles for at least some physician-scientists in taking on high-profile public engagement activities.
As of 2019, science is losing the battle to antiscience, and now children are increasingly denied the fundamental right of access to vaccines.
Dr. Peter Hotez is the dean for the National School of Tropical Medicine at Baylor College of Medicine in Houston.