The world has bet the farm on vaccines as the solution to the pandemic, but the trials are not focused on answering the questions many might assume they are. Peter Doshi reports
As phase III trials of covid-19 vaccines reach their target enrolments, officials have been trying to project calm. The US coronavirus czar Anthony Fauci and the Food and Drug Administration leadership have offered public assurances that established procedures will be followed.1234 Only a “safe and effective” vaccine will be approved, they say, and nine vaccine manufacturers issued a rare joint statement pledging not to prematurely seek regulatory review.5
But what will it mean exactly when a vaccine is declared “effective”? To the public this seems fairly obvious. “The primary goal of a covid-19 vaccine is to keep people from getting very sick and dying,” a National Public Radio broadcast said bluntly.6
Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston, said, “Ideally, you want an antiviral vaccine to do two things . . . first, reduce the likelihood you will get severely ill and go to the hospital, and two, prevent infection and therefore interrupt disease transmission.”7
Yet the current phase III trials are not actually set up to prove either (reduce fatalities/reduce transmissions) (table 1).
None of the trials currently under way are designed to detect a reduction in any serious outcome such as hospital admissions, use of intensive care, or deaths.
Nor are the vaccines being studied to determine whether they can interrupt transmission of the virus.
What's the point of this vaccine?
Evaluating mild, not severe, disease
In a September interview Medscape editor in chief Eric Topol pondered what counts as a recorded “event” in the vaccine trials. “We’re not talking about just a PCR [polymerase chain reaction test]-positive mild infection. It has to be moderate to severe illness to qualify as an event, correct?” he asked.8
“That’s right,” concurred his guest, Paul Offit, a vaccinologist who sits on the FDA advisory committee that may ultimately recommend the vaccines for licence or emergency use authorisation.
But that’s not right. In all the ongoing phase III trials for which details have been released, laboratory confirmed infections even with only mild symptoms qualify as meeting the primary endpoint definition.9101112 In Pfizer and Moderna’s trials, for example, people with only a cough and positive laboratory test would bring those trials one event closer to their completion. (If AstraZeneca’s ongoing UK trial is designed similarly to its “paused” US trial for which the company has released details, a cough and fever with positive PCR test would suffice.)
All my readers are fully aware of the huge problem with the PCR tests, right? Therefore if a "positive" PCR test and a cough or a PCR test with cough & fever would suffice does that indicate an active case. Not by a long shot.
Recall this previous post? Study of UK key workers shows around half (49%) who self reported COVID-19 symptoms did not have the disease
Part of the reason may be numbers. Severe illness requiring hospital admission, which happens in only a small fraction of symptomatic covid-19 cases, would be unlikely to occur in significant numbers in trials. (So why is a vaccine necessary?) Data published by the US Centers for Disease Control and Prevention in late April reported a symptomatic case hospitalisation ratio of 3.4% overall, varying from 1.7% in 0-49 year olds and 4.5% in 50-64 year olds to 7.4% in those 65 and over.13 Because most people with symptomatic covid-19 experience only mild symptoms,14 even trials involving 30 000 or more patients would turn up relatively few cases of severe disease. (Again, why is a vaccine required?)
In the trials, final efficacy analyses are planned after just 150 to 160 “events,”—that is, a positive indication of symptomatic covid-19, regardless of severity of the illness.
Yet until vaccine manufacturers began to release their study protocols in mid-September, trial registries and other publicly released information did little to dispel the notion that it was severe covid-19 that the trials were assessing. Moderna, for example, called hospital admissions a “key secondary endpoint” in statements to the media.15 And a press release from the US National Institutes of Health reinforced this impression, stating that Moderna’s trial “aims to study whether the vaccine can prevent severe covid-19” and “seeks to answer if the vaccine can prevent death caused by covid-19.”16
But Tal Zaks, chief medical officer at Moderna, told The BMJ that the company’s trial lacks adequate statistical power to assess those outcomes. “The trial is precluded from judging [hospital admissions], based on what is a reasonable size and duration to serve the public good here,” he said.
Hospital admissions and deaths from covid-19 are simply too uncommon in the population being studied for an effective vaccine to demonstrate statistically significant differences in a trial of 30 000 people. The same is true of its ability to save lives or prevent transmission: the trials are not designed to find out.
Zaks said, “Would I like to know that this prevents mortality? Sure, because I believe it does. I just don’t think it’s feasible within the time frame [of the trial]—too many would die waiting for the results before we ever knew that.”
What about Hotez’s second criterion, interrupting virus transmission, which some experts have argued17 should be the most important test in phase III studies?
“Our trial will not demonstrate prevention of transmission,” Zaks said, “because in order to do that you have to swab people twice a week for very long periods, and that becomes operationally untenable.”
He repeatedly emphasised these “operational realities” of running a vaccine trial. “Every trial design, especially phase III, is always a balancing act between different needs,” he said. “If you wanted to have an answer on an endpoint that happens at a frequency of one 10th or one fifth the frequency of the primary endpoint, you would need a trial that is either 5 or 10 times larger or you’d need a trial that is 5 or 10 times longer to collect those events. Neither of these, I think, are acceptable in the current public need for knowing expeditiously that a vaccine works.”
Are you reading what is being stated in this report. Reading and understanding that there is zero real evidence to support the idea that these vaccines will save lives. Stop transmission. Or, reduce illness.
Zaks added, “A 30 000 [participant] trial is already a fairly large trial. If you’re asking for a 300 000 trial then you need to talk to the people who are paying for it, because now you’re talking about not a $500m to $1bn trial, you’re talking about something 10 times the size. And I think the public purse and operational capabilities and capacities we have are rightly spent not betting the farm on one vaccine but, as Operation Warp Speed [the US government’s covid-19 vaccine plan] is trying to do, making sure that we’re funding several vaccines in parallel.”
Still, it’s fair to say that most of the general public assumes that the whole point of the current trials, besides testing safety (box 1), is to see whether the vaccine can prevent bad outcomes. “How do you reconcile that?” The BMJ asked Zaks.
I've added the text from box 1 directly below:
Safety and side effects
History shows many examples of serious adverse events from vaccines brought to market in periods of enormous pressure and expectation. There were contaminated polio vaccines in 1955, cases of Guillain-Barré syndrome in recipients of flu vaccines in 1976, and narcolepsy linked to one brand of influenza vaccine in 2009.1819
*Contaminated polio vaccines includes the Cutter Incident and SV 40 (Simian Virus 40)
In 1960 Bernice Eddy, a government researcher, discovered that when she injected hamsters with the kidney mixture on which the vaccine was cultured, they developed tumors. Eddy's superiors tried to keep the discovery quiet, but Eddy presented her data at a cancer conference in New York. She was eventually demoted, and lost her laboratory. The cancer-causing virus was soon isolated by other scientists and dubbed SV40, because it was the fortieth simian virus discovered.
* Guillain Barre Syndrome was a result of the "swine flu of '76 (You'll find info on that in the coverage of the 09 Swine Flu pandemic
* Many cases of Narcolepsy were linked to the swine flu vaccine from the pandemic of '09 - There are many reports here covering that forgotten, swept under the rug pandemicBack to the bmj report
“Finding severe rare adverse events will require the study of tens of thousands of patients, but this requirement will not be met by early adoption of a product that has not completed its full trial evaluation,” Harvard drug policy researchers Jerry Avorn and Aaron Kesselheim recently wrote in JAMA.20
Covid-19 vaccine trials are currently designed to tabulate final efficacy results once 150 to 160 trial participants develop symptomatic covid-19—and most trials have specified at least one interim analysis allowing for the trials to end with even fewer data accrued.
Medscape’s Eric Topol has been a vocal critic of the trials’ many interim analyses. “These numbers seem totally out of line with what would be considered stopping rules,” he says. “I mean, you’re talking about giving a vaccine with any of these programmes to tens of millions of people. And you’re going to base that on 100 events?”8
Great uncertainty remains over how long a randomised trial of a vaccine will be allowed to proceed. If efficacy is declared, one possibility is that the thousands of volunteers who received a saline placebo would be offered the active vaccine, in effect ending the period of randomised follow-up. Such a move would have far reaching implications for our understanding of vaccines’ benefits and harms, rendering uncertain our knowledge of whether the vaccines can reduce the risk of serious covid-19 disease and precluding any further ability to compare adverse events in the experimental versus the placebo
“Very simply,” he replied. “Number one, we have a bad outcome as our endpoint. (That's not accurate since Covid-19 has a very high survival rate) It’s covid-19 disease.” Moderna, like Pfizer and Janssen, has designed its study to detect a relative risk reduction of at least 30% in participants developing laboratory confirmed covid-19, consistent with FDA and international guidance.2122
Number two, Zaks pointed to influenza vaccines, saying they protect against severe disease better than mild disease. To Moderna, it’s the same for covid-19: if its vaccine is shown to reduce symptomatic covid-19, it will be confident it also protects against serious outcomes.
But the truth is that the science remains far from clear cut, even for influenza vaccines that have been used for decades. Although randomised trials have shown an effect in reducing the risk of symptomatic influenza, such trials have never been conducted in elderly people living in the community to see whether they save lives.
Only two placebo controlled trials in this population have ever been conducted, and neither was designed to detect any difference in hospital admissions or deaths.23 Moreover, dramatic increases in use of influenza vaccines has not been associated with a decline in mortality (box 2).26
Read the entire report- check the references