Johns Hopkins’s Center for Immunization Research is enrolling otherwise healthy medical subjects to be injected and infected with Zika, the virus associated with microcephaly that created a global panic in 2015-2016.
Undoubtedly, care is being taken so that Zika won’t escape, via sexual activity or an unseen mosquito bite by locally endemic Aedes albopictus, to cross-infect and contaminate the region. But even with precautions in place, the question arises: Why are government-funded investigators, six years after the Zika epidemic vanished, deliberately infecting U.S. citizens now?
This rather unusual “Human Challenge Trial” seems to be the public health response to the question of what had kept the well-funded, long-promised, but unrealized Zika vaccine from completion and distribution.
Despite two years of frenetic activity, beginning with a $400 million appropriation in September 2016, the Zika vaccine endeavor lost steam because there was no “there” there. Zika’s abrupt disappearance had eliminated the background incidence of natural infection that was necessary to validate vaccine trials.
This is why, even though pharmacological science and industry were thus able to produce a COVID-19 vaccine within a year, the Zika vaccine efforts have gotten nowhere.
In 2018, researchers attempted to circumvent the “problem” of Zika’s absence by promoting a Zika human challenge trial. This meant infecting healthy Brazilian subjects with a virus that had stopped infecting people. In personal communications, Johns Hopkins’s Dr. Anna Durbin revealed that Brazil’s version of the FDA had refused to conduct such experiments. For that reason, she set out to conduct such an experiment stateside.
Is Dr. Durbin correct in doing so? Understanding Zika-microcephaly’s recent trajectory helps in this decision.
In 2015, the Zika-microcephaly pandemic took hold in Recife, Brazil. Flavivirus Zika, for decades seen as harmless, was now suddenly deemed responsible for congenital microcephaly (small heads, diminished intellect). Massive panic predictably ensued.
Clinical tests for Zika did not exist until after the peak, and microcephaly determinations had no firm diagnostic standard for frequency comparisons within Brazil, nor in any prior registry. Ultimately, only 1 in 20 microcephaly diagnoses persisted under later review. In January 2016, the World Health Organization’s Bruce Aylward acknowledged, “In any unfolding crisis you’re dealing with a lot of uncertainty (including the precise nature of any link between Zika and microcephaly).” By February 2016, the WHO had pivoted, declaring Zika a worldwide public health emergency.
The CDC then issued a travel advisory for 14 Latin American countries. Debate arose over canceling the Olympics in Rio De Janeiro, 1,500 miles from the outbreak’s epicenter. Brazil’s military was mobilized for insect reduction. Health ministers, led by WHO-aligned experts, recommended that women forgo childbirth, completely and indefinitely, anticipating a near-future Zika vaccine for their populace.
Federal funds of the National Institute of Allergy and Infectious Diseases were even “borrowed” from other purposes to create such a vaccine, presuming that active infection would persist. It did not.
Institutionally haunted by fallout from the Tuskegee and Guatemala syphilis human challenge experiments, NIAID sponsored an ethics panel in late 2016. It concluded by specifically forbidding any sort of human challenge trial involving Zika, given that the disease is nonfatal and avoidable.
But NIAID’s Dr. Anthony Fauci, apparently ignoring the ethics panel’s advice, endorsed a Brazilian trial of this kind in 2018, all the while acknowledging that Zika may have been a one-hit wonder. “It’s a risk that you’ll spend this money and never use the vaccine,” he said.
The New York Times adequately summed up the controversy, noting that although scientists were saying a human challenge trial “is necessary to prevent a future epidemic … bioethicists had concluded the research had ‘insufficient value’ to justify the risks.”
Ultimately, Brazil chose NIAID’s ethics panel over its official recommendations. It stands to reason. In fact, every further Zika vaccine tax dollar represents waste, fraud, and abuse. To infect humans so long after Zika’s disappearance implies either a harmless virus or a heartless study. Either possibility undercuts the rationale.
Dr. Durbin sees Zika as both dangerous and dormant, cyclically awakening. With only one data point, this is unverifiable.
In 1965, Dr. Irwin Schatz (father to Hawaii’s senior U.S. senator) objected to the NIH’s use of impoverished test subjects as collateral damage in the Tuskegee study. In its earliest phases, before penicillin, Tuskegee had diagnostic value. The real sin was in its continuation — willfully ignoring changed medical circumstances, endangering subjects, and aggrandizing observers.
Let’s learn from our errors and stop this Zika human experiment. If a Zika revival warrants this vaccine’s revival, then there are more robust interim vaccine techniques that will bridge the gap.
Randall S. Bock, M. D. is a practicing primary care physician in the Boston area and the author of Overturning Zika (2022) and Investigating Zika-Microcephaly’s ‘Crash’ (American Journal of Medicine, 2022).
