Editor’s note: This article is Part 1 in a series exploring vaccine clinical trials. Read Part 2 here.
U.S. Secretary of Health and Human Services (HHS) Robert F. Kennedy Jr. recently made headlines by calling for future vaccine studies to employ placebo-controlled trials.
“All new vaccines will undergo safety testing in placebo-controlled trials prior to licensure — a radical departure from past practices,” an HHS spokesperson told The Washington Post. Many hailed the proposal as a courageous move toward transparency and rigorous scientific standards.
Indeed, a double-blind, placebo-controlled trial is considered the “gold standard” for clinical trials, because it has the best chance of determining whether an active treatment is effective.
What is a placebo-controlled trial?
In a placebo-controlled trial, there are two (or more) groups. One group gets the active treatment (vaccine, for example), the other gets the placebo, an inactive substance that looks and tastes like the drug being tested but has no effect on the disease the new drug is intended to treat.
Double-blinded means that neither the researchers nor the research participants know who is getting active medication and who is getting a placebo.
Ideally, this blinding principle also extends to other parties, including researchers, technicians, data analysts and evaluators. Effective blinding experimentally isolates the physiological effects of treatments from various psychological sources of bias.
In this context, Kennedy’s spokesperson, Andrew Nixon, told Forbes, “Except for the COVID vaccine, none of the vaccines on the CDC’s childhood recommended schedule were tested against an inert placebo, meaning we know very little about the actual risk profiles of these products.”
Why wouldn’t everyone support Kennedy’s plan for placebo-controlled trials? Because the vaccine debate is one of the media’s hottest topics.
It is argued, for example, that there have indeed been placebo studies — and that these have shown that the vaccines were superior to the placebos. Public health scientist Dr. Jess Steier recently cited Dr. Jonas Salk’s polio vaccine trial as an example.
In Salk’s study, “623,972 children received vaccine or saline placebo, and an additional 1 million-plus children served as observed controls,” Steiner wrote. “Results: [Salk’s polio vaccine was] 80-90% effective against paralytic polio, no unexpected side effects. Impact: Cases dropped from 58,000 (1957) to 161 (1961).”
This may sound convincing at first glance, but on closer inspection, these statements are unsubstantiated.
Jonas Salk on the Time cover from March 29, 1954.
Before we start picking apart Steier’s claims, we should credit her for citing a few placebo vaccine studies. Believe it or not, this is anything but self-evident.
For example, on May 1, NPR quoted Dr. Jesse Goodman, a former U.S. Food and Drug Administration (FDA) vaccine regulator now at Georgetown University, who claimed: “The blanket statement that none of the routine vaccines were ever tested against a placebo is incorrect. Placebo trials have been done.”
However, NPR mentions only one such study: “That includes the original COVID vaccines, which were evaluated in large, well-designed placebo-controlled trials.”
Even though the subhead reads, “Placebo-controlled vaccine trials have been common,” not a single other placebo vaccination study is mentioned in the NPR article.
Goodman can then also claim that “the COVID vaccine trials have clearly shown that … [these injections] are safe and effective” — an assertion that has no factual basis, as we will show later.
What about Salk’s polio vaccine trial?
It should be noted that early electron microscopy studies, such as the 1949 work by Rhian, Lensen and Williams, found that so-called viral particles claimed to be from poliomyelitic tissue were indistinguishable from those in healthy controls — casting doubt on the specificity of the virus identification itself.
The researchers concluded that there was no definitive proof that a poliovirus had ever been visualized or isolated by the standards of electron microscopy.
Similarly, Joseph L. Melnick wrote in 1951 that, despite numerous attempts, there was still no clear evidence the poliovirus had ever been obtained in purified form or seen directly under the electron microscope when proper controls were used.
These early insights suggest that even foundational assumptions about the polio virus itself — and thereby the rationale for the vaccine — deserve renewed scientific scrutiny.
Even if we assume that the calculated relative risk reduction of approximately 72% for paralytic polio is correct, the absolute risk reduction was modest at 0.041% — meaning 2,439 vaccinations were required to prevent a single case of paralytic polio.
Furthermore, there has been a lack of complete randomization and blinding in observational and null groups, and potential biases and statistical manipulations due to health behaviors and reporting practices. And the pressure to deliver something of great success should not be underestimated!
In this context, Hilary and Peter Butler write in their book, “From One Prick to Another”:
“Someone like Jonas Salk couldn’t make a mistake, could he? Medical history records that the data was wrong (not that the average person on the street knows that), but such was the aura of the man at the time, the‚ magnificence of the project, the years of research and the vast amount of money poured into the vaccine, and so great was the need for it to succeed, that cognitive dissonance and the fallacy of authority got in the way, and the mistake in the data was ignored.”
Salk’s polio trial ‘classic example’ of data being both wrong, and ignored
The Butlers state that the Salk polio trial data are “a classic example of data being wrong, and ignored at the same time.”
Dr. Paul Meier sat in on the meeting where Jonas Salk explained the safety testing procedures for the early Salk polio vaccine. As Meier looked at the data, “he realized the data didn’t say what Salk said it said, so he wrote an analysis showing the flaws,” the Butlers wrote.
We also have to consider that only a statistical expert could evaluate the results of the “Francis report.” (Thomas Francis Jr. was the author of the 1954 study, not Jonas Salk, because Francis was appointed as the independent lead evaluator of the clinical trial — not as the developer of the vaccine. In other words, to avoid conflicts of interest, Salk did not himself evaluate the huge clinical trial).
The tests, whose results were presented at a meeting of 500 doctors and scientists in Ann Arbor, Michigan, were conducted in 44 states and involved nearly 2 million children.
“As statisticians of the calibre of Bradford Hill and the late Major Greenwood have pointed out, there are many sources of fallacy to be avoided when making comparisons between inoculated and uninoculated groups of people,” wrote M. Beddow Bayly in 1956 in his article, “The Story of the Salk Anti-Poliomyelitis Vaccine.”
“Only a close study of all the relevant factors would enable one to decide whether the groups in these tests are strictly comparable in all respects save that of the one to be evaluated,” Bayly concluded.
In fact, the Francis Report reveals that in one large section of the trials, the inoculated children were not of the same age group as the uninoculated controls. The British Medical Journal on April 30, 1955, called attention to this doubtful procedure, stigmatizing it as “open to criticism.”
The BMJ wrote:
“It may not be a fair assumption, for instance, that the experience of second-grade children would be the average of that for the first and third grades in the absence of vaccination. A more serious bias lies in the selection of children in the second grade whose parents agreed to have them vaccinated.”
According to Bayly, “It is recognised among statisticians engaged in similar assessments that the social position and the care lavished upon the children in families of volunteers for inoculation are likely to be superior to that of the controls generally, and that this would affect the validity of conclusions.”
‘Poliomyelitis is not beaten’
Bayly suggested another source of error, not mentioned in the Francis report but recorded in a New York Times page 1 piece from April 13, 1955. The article states that it “require[s] two inoculations spaced two to four weeks apart, with a third, booster shot seven months later” to receive “100 percent protection from paralysis,” as Salk is being quoted.
According to Bayly, “This means that a child developing poliomyelitis after the first inoculation and before the second would automatically be placed in the uninoculated class. If this is true, it is obvious that any conclusions drawn from his figures would be invalidated.”
Bayly also mentions a comment by Dr. Anthony M. M. Payne of the World Health Organization, which Bayly said “was certainly justified and salutary.”
On April 14, 1955, Payne told the Manchester Guardian:
“Poliomyelitis is not beaten. We do not know how long the [vaccine’s] effect lasts; we do not know if it will work in infants; we do not know if it will be effective under other conditions than those in which it was used; we do not know how best to use it. We do know that there are many intricate problems in the manufacture of this vaccine.”
Indeed, only 13 days after the polio vaccine had been acclaimed by the whole of the American Press and Radio as one of the greatest medical discoveries of the century, and two days after the English Minister of Health announced he would go right ahead with the manufacture of the vaccine, came the first news of disaster.
Children inoculated with one brand of vaccine had developed poliomyelitis. In the following days, more and more cases were reported, some of them after inoculation with other brands of the vaccine.
Within only two weeks, the number of polio cases among vaccinated children had climbed to nearly 200. On May 6, 1955, the News Chronicle quoted the U.S. government’s highest authority on viruses, Carl Eklund, who said that in the U.S., only vaccinated children had been afflicted by polio. And only in areas where no polio cases had been reported during the first three-quarters of a year.
In nine of 10 cases, the paralysis appeared in the injected arm. This triggered panic in the White House. On May 8, the American government completely halted production of the vaccine.
A short time later, another 2,000 polio cases were reported in Boston, where thousands had been vaccinated. In “inoculated” New York, the number of cases doubled. In Rhode Island and Wisconsin, they jumped by 500%. The lameness appeared in the inoculated arm in many children.
Statistics show no reason to celebrate Salk’s vaccine
Apart from that, an objective look at statistics would have shown that there was no reason to celebrate Salk’s vaccine as the great conqueror of an alleged polio virus.
“According to international mortality statistics, from 1923 to 1953, before the Salk killed-virus vaccine was introduced, the polio death rate in the United States and England had already declined on its own by 47 percent and 55 percent respectively,” wrote scientific journalist Neil Miller (see diagram below).
From 1923 to 1953, long before large-scale polio vaccinations began to be carried out in the mid-1950s, mortalities attributed to polio had already decreased substantially: In the USA by 47 percent; in Great Britain by 55 percent; in other European countries, the statistics are comparable. This diagram was reproduced with permission from the following book: Vaccines: Are They Really Safe and Effective? © Neil Z. Miller.
And what emerges from the polio graph also emerges from the historical data on all other “infectious diseases.” We will explore this in Part 2 of this series.
