Published December 6, 2016
The World Health Organization (WHO) defines a vaccine as a "biological preparation that improves immunity to a particular disease." The...
— William Wilberforce
The director of the U.S. Centers for Disease Control and Prevention, Tom Frieden, MD, recently wrote an opinion piece titled “CDC Chief: Zika is Coming. To fully Protect Americans We Must Have the Funds We Need.”1 As the title suggests, the aim of the article is to lobby Congress for funds to conduct more research on the Zika virus which has been theorized to be causing some of the cases of microcephaly in Latin America, notably in Brazil. Certainly, the end of the article makes no bones about Dr. Frieden’s intent.
CDC’s mission and commitment is to protect the health, safety and security of Americans—and without Zika supplemental funding requested by the Obama administration, we won’t be able to provide the robust protection against Zika that Americans deserve. There is something everyone can do to control this emerging epidemic and to protect our next generation from this newly discovered threat, and we must act now.1
The money to which Dr. Frieden is referring is the $1.9 billion in “emergency supplemental appropriations” the White House requested from Congress on Feb. 22, 2016.2 3 Of the total amount, $828 million would go to the CDC, partly to perform additional research to understand the “clinical and epidemiological patterns to make [the causal connection between Zika and microcephaly] definitive.”4 The funding would represent a 12% increase in the CDC’s annual budget of approximately $7 billion.5
The problem with Dr. Frieden’s letter is that it fuels the perception that Zika does, in fact, cause microcephaly—a direct link for which there is no conclusive scientific evidence. While there have been some microcephaly cases in Brazil in which the fetus or baby tested positive for Zika virus, there is no way tell if the virus actually caused the microcephaly. This is correlation, not causation, and it is not enough to justify arguing or insinuating a causal relationship. Yet, that is precisely what Dr. Frieden’s letter does.
The letter starts off:
At the Centers for Disease Control and Prevention we’ve learned to expect the unexpected the unexpected—but the ongoing Zika outbreak has caused dangers from a mosquito bite no one imagined: birth defects.1
To say that the “Zika outbreak has dangers from a mosquito bite no one imagined: birth defects” strongly implies a causal relationship.
In the second paragraph, Dr. Frieden writes:
The reported association between Zika virus infection and microcephaly (small head size) is unfortunately likely to be part of a spectrum of brain damage that results from this virus invading the brain of the developing fetus.1
Here, it sounds as if Dr. Frieden is walking it back a little (“reported association between Zika virus infection and microcephaly”) so as not to commit entirely to the idea of a causal relationship but still manage to create the illusion of that relationship toward the end that sentence (“brain damage that results from this virus invading the brain of the developing fetus”).
The third paragraph begins, “There are many unknowns with this virus…” The fourth paragraph again implies a causal relationship. It starts off like this:
The U.S. Commonwealth of Puerto Rico has had hundreds of locally acquired cases of Zika, and we expect that by the end of the year they could have hundreds of thousands of cases and thousands of infected pregnant women.1
Toward the end of the letter, Dr. Frieden walks it back yet again, and then proceeds again to imply a causal connection. He writes:
We are working to further evaluate the relationship between Zika and microcephaly, as well as with other neurological conditions such as Guillain-Barré syndrome. With the National Institutes of Health as the lead and support from the Biomedical Advanced Research and Development Authority (BARDA), we are working to accelerate vaccine development to fully protect our future generations.1
“We are working to further evaluate the relationship between Zika and microcephaly…” clearly suggests that they do not have all the proof they need to make the connection. Yet, they “are working to accelerate vaccine development to fully protect our future generations.” That sounds like they’re in crisis mode, because… well, they’ve determined a causal relationship? (And speaking of crisis mode, what is BARDA6 doing in the mix? How has the rush to develop a vaccine for a virus that the CDC still doesn’t understand been elevated to a medical countermeasure status, which implies a national security threat?)
The letter reads like a roller coaster ride. It’s dizzying. But the overall impression you get is unmistakable: Zika virus causes microcephaly. That’s a bit disingenuous. What’s worse is that the letter makes no mention of the fact that there are many other known causes of microcephaly. However, the CDC does not appear to be pursuing those. The agency is clearly in Zika mode. It’s almost as if the CDC has a case of tunnel vision.
We know, for example that severe malnutrition in pregnant women can cause microcephaly in babies. The CDC has long acknowledged this, and it says so on its website.7 The CDC also knows that alcohol use by pregnant women can cause microcephaly in babies. It’s on the CDC’s website.7 The CDC also knows that drug use by pregnant women can cause microcephaly in babies. Again, on the website.7 The CDC also knows that exposure to toxic chemicals in pregnant woman can cause microcephaly in babies. On the website.7
The agency also knows that certain infections during pregnancy, such as rubella, toxoplasmosis and cytomegalovirus can cause microcephaly in babies. Plain as day, on the website.7 Then there are cases in which an interruption of blood supply to the infant’s brain during its development in utero can cause microcephaly in babies. Website.7
Dr. Frieden’s letter does not allude to any of these other causes of microcephaly. Remember, these are known causes. Neither does Dr. Frieden explain why so much emphasis is being given to Zika when the CDC has long known that the virus is relatively harmless and causes no symptoms in most of the people who contract it, and only mild symptoms in most others who have it. The agency says so on its website.7
Wouldn’t it make more sense to focus first on those things we know cause microcephaly and rule them out, rather than prematurely scaring the heck out of the American public, particularly pregnant women, and inventing a health crisis where there may, in fact, be none? The Zika scare has already fired up an international race to develop a Zika vaccine that may not be needed, but will assuredly, eventually be marketed as another “life-saving” vaccine that everyone will be mandated to get.
1 Frieden T. CDC Chief: Zika is coming. To fully protect Americans we must have the funds we need. Fox News Apr. 1, 2016.
2 Dennis B. Obama asks Congress for $1.9 billion to combat spread of Zika virus. The Washington Post Feb. 22, 2016.
3 Obama BH. Letter to The Honorable Paul D. Ryan, Speaker of the House of Representatives. The White House Feb. 22, 2016.
4 Fromson N. CDC: Strong evidence of link between Zika and microcephaly. United Press International Feb. 11, 2016.
5 Nather D, Scott D. Congress ready to give NIH its biggest increase in 12 years. STAT Dec. 16, 2015.
6 U.S. Department of Health and Human Services. Medical Countermeasures: Biomedical Advanced Research and Developments Authority (BARDA).
7 U.S. Centers for Disease Control and Prevention. Birth Defects, Facts about Microcephaly. CDC. gov.