Also published at The Brownstone Institute (as “The Paucity of Evidence for Mandated Covid-19 Vaccine Boosters”)
Federal legal challenges have temporarily enjoined the Biden Administration’s sweeping large business, health care worker, and federal contractor covid-19 vaccine mandates. Notwithstanding these injunctions staying primary covid-19 vaccine mandates, “amendments” mandating booster covid-19 vaccinations have already been issued, as examples, for New Mexico healthcare workers, and University of Massachusetts-Amherst students.
Dr. Allon Friedman’s recent Brownstone essay, citing randomized, controlled trial data on primary covid-19 vaccination, demonstrated,
Therefore, [covid-19] vaccine mandates, which are enormously costly and terribly divisive, are a cure worse than the disease.
Why did Dr. Friedman rely exclusively—and appositely—upon randomized, controlled trial data to justify his conclusion?
Almost sixty years ago (in 1963) Campbell and Stanley published their seminal monograph on research methodology entitled “Experimental and Quasi-Experimental Designs for Research.” This work, which shaped research designs ever since highlighted the major threats to validity that are avoided, uniquely, by the randomized controlled trial—a true experimental design. Observational studies and all other non-randomized designs lacking parallel control groups, which they referred to as “quasi-experimental”, are fraught with known biases investigators attempt to control for, after the fact, with limited success. Worse still are intractable, unknown biases which the randomization process, alone, accounts for. Guyatt and colleagues, in their 2008 British Medical Journal paper “GRADE: an emerging consensus on rating quality of evidence and strength of recommendations”, updated and reinforced these ideas, appropriately assigning highest priority to randomized, controlled trial evidence.
Friday, 11/19/21, CDC Director Dr. Walensky endorsed the expanded recommendations of the CDC Advisory Committee on Immunization Practices (ACIP) that booster (third dose) shots be provided to all adults 18 years of age, and older, who received their second Pfizer or Moderna mRNA vaccine second doses, at least 6-months earlier. What randomized, controlled trial evidence was the basis for this “unanimous decision,” touted by Dr. Walensky?
Although two small, published, randomized, placebo-controlled trials—one in kidney transplant recipients, and another in a general population—revealed enhanced immune responses to boosters, CDC’s recommendation clearly hinged upon a large, unpublished Pfizer randomized, placebo-controlled clinical trial.
A month before the CDC expanded booster recommendation was announced, Pfizer’s “randomized trial results by press release” were issued (10/21/21). The ~10,000 person, placebo-controlled randomized covid-19 vaccine booster trial, yielded a 95.6% reduction in symptomatic covid-19 infections (i.e., 109 in the placebo group; 9 in the boosted group), after a median 2.5 months of follow-up. The press release also included this important caveat:
“The observed relative vaccine efficacy of 95.6% (95% CI: 89.3, 98.6) reflects the reduction in disease occurrence in the boosted group versus the non-boosted group in those without evidence of prior SARS-CoV-2 infection.”
The 11/19/21 ACIP presentation of Pfizer’s Dr. John Perez included enough data about prior infection to conclude boosters did not reduce covid-19 infections relative to placebo in this clinically relevant, ever burgeoning subgroup. Simple calculations (based upon the slides from pages 16 and 17) indicate there were only 2 symptomatic covid-19 infections among the 524 trial participants with a history of prior SARS-CoV-2 infection, 1/275 who received boosters, and 1/249 given placebo injections (p=0.944 for incidence rate difference of 0.038%).
Moreover, CDC’s Dr. Oliver, in her ACIP review (p. 25) of Pfizer’s booster trial data, acknowledged that within the full cohort of ~10,000 there were no covid-19 hospitalizations or deaths, and no data to assess any impact on SARS-CoV-2 transmission.
These findings comprise a striking paucity of randomized trial evidence on the “efficacy” of boosters—literally none on the most clinically relevant outcomes of serious covid-19 morbidity and mortality. Even the potential effect of boosters on SARS-CoV-2 transmission remains unaddressed.
Rapidly accumulating data strongly suggest prior covid-19 infection, “natural immunity,” is more robust, flexible, and enduring than exclusive covid-19 vaccine-acquired immunity. Pfizer’s covid-19 booster trial data confirm boosters afford no benefit in preventing covid-19 infections among those with natural immunity.
Given these overall randomized trial findings regarding covid-19 vaccine boosters—absence of even a short- term reduction in mild covid-19 infections in those with natural immunity, and no data establishing that boosters prevent covid-19 hospitalizations, deaths, or SARS-CoV-2 transmission—there is no rational, evidence-based justification for covid-19 vaccine “booster mandates.”