“A groundbreaking preprint paper by the prestigious Oxford University Clinical Research Group … includes alarming findings devastating to the COVID vaccine rollout,” Children's Health Defense (CHD) warned on August 23. “The study found vaccinated individuals carry 251 times the load of COVID-19 viruses in their nostrils compared to the unvaccinated.”
If you're a regular ACSH reader, you know that CHD is Robert F. Kennedy Jr.'s infamous anti-vaccine group. It has dishonestly alleged that the coronavirus pandemic was planned at least two years in advance and that the Pfizer-BioNTech shot makes you more susceptible to SARS-COV-2 variants. As with these earlier examples, CHD's most recent assertion is absurd. Let's take a closer look at the study itself and compare its conclusions to those of CHD's article. You'll notice the divergence rather quickly.
Anytime you read a news story about a study, look at the study directly. Don't take the summary of a journalist or activist at face value. A few things stuck out to me when I read through the paper CHD cited. First, the researchers investigated breakthrough infections in just 69 health care workers at a Vietnamese hospital. Whatever its conclusions, such a small sample size can't tell us anything statistically meaningful about the efficacy of COVID vaccines.
This doesn't mean the paper itself is useless, just that its results need to be peer-reviewed and replicated before we can say anything with confidence about its conclusion.
That leads us to a very important point. Many, much larger studies have shown that the existing vaccines prevent the majority of infections, even those caused by Delta. This was confirmed earlier this week by a new CDC report:
During December 14, 2020–August 14, 2021, full vaccination with COVID-19 vaccines was 80% effective in preventing RT-PCR–confirmed SARS-CoV-2 infection among frontline workers, further affirming the highly protective benefit of full vaccination up to and through the most recent summer U.S. COVID-19 pandemic waves.
The agency acknowledged that vaccine efficacy declined post-Delta, but this needs to be considered in context. “Although these interim findings suggest a moderate reduction in the effectiveness of COVID-19 vaccines in preventing infection,” the CDC wrote, “the sustained two-thirds reduction in infection risk underscores the continued importance and benefits of COVID-19 vaccination.” The agency reported in a separate analysis that infection and hospitalization rates in the unvaccinated were 4.9 and 29.2 times higher than those of fully vaccinated persons in Los Angeles.
What the study really found
Setting aside infection risk for just a second, what this pre-print paper actually showed is that the AstraZeneca vaccine worked remarkably well. Forty-seven of the 69 participants developed respiratory symptoms, but they all recovered from infection, and only one required any sort of medical treatment—three days of oxygen supplementation (See table 1 below). The authors correctly concluded that their study is "in line with recent reports regarding the vaccine effectiveness in protecting against severe disease."
Another crucially important point: the study participants care for sick people all day in a poorly ventilated infectious disease hospital, “a well-known indoor setting that could facilitate the transmission of SARS-CoV-2,” the authors wrote. If there's one lesson to take away from this paper, it's that the vaccines offered substantial protection despite this infection-friendly setting. Previous (and much larger) studies of health care workers have reached the same conclusion.
CHD's assertion that “Vaccinated individuals are blasting out concentrated viral explosions into their communities and fueling new COVID surges” is therefore ridiculous. It's well known that pathogens spread much more efficiently when they're not up against effective vaccines. With that in mind, recall that Delta originated last December in India, a country with very low vaccine coverage; just under 23 percent of its population was fully vaccinated as of August 22.
In sum, when breakthrough cases occur, they tend to be far less severe. COVID-19 remains a disease mostly of the unvaccinated. And CHD continues to be hopelessly dishonest.
Cameron English
Director of Bioscience
Cameron English is a writer, editor and co-host of the Science Facts and Fallacies Podcast. Before joining ACSH, he was managing editor at the Genetic Literacy Project.
