Family physician Daniel Stock repeated previously debunked misinformation about COVID-19 vaccines, treatments, and control strategies in a Mount Vernon School Board Meeting

Face masks don’t reduce the spread of respiratory infections; COVID-19 vaccines are ineffective, and may lead to more severe disease; ivermectin, vitamin D, and zinc are effective COVID-19 treatments
Misleading: The fact that face masks or vaccines aren't 100% effective doesn't render them useless. Several studies demonstrate that face masks effectively reduce the transmission of COVID-19 and other respiratory viruses in community settings. Even if they don't completely prevent infection or disease, vaccines have proven one of the most effective tools to control the spread of infectious diseases.
Incorrect: COVID-19 vaccines reduce the likelihood of infection in previously infected individuals, contradicting the claim that vaccination provides no benefit for them.
Unsupported: COVID-19 vaccines haven't shown signs of antibody-dependent enhancement (ADE) in animal studies or vaccinated people. In fact, vaccination reduces the risk of infection and the disease severity, which is the opposite of what happens in ADE. There is no reliable evidence that either ivermectin or vitamin D and zinc supplementation effectively prevent or treat COVID-19.
Vaccination is one of the most effective ways to protect individuals and communities from potentially harmful diseases. History shows that vaccines don’t need to completely block infection or eradicate the disease to control the spread of infectious diseases within a population. COVID-19 vaccines can effectively reduce infections and prevent over 90% of severe illnesses and deaths, making them one of our best tools to curb the pandemic.

FULL CLAIM: “Coronaviruses and all other respiratory viruses [...] spread by aerosol particles, which are small enough to go through every mask”; “all respiratory viruses [...] circulate all year long waiting for the immune system to get sick through the winter or become deranged”; “no one can make this virus go away”; “why is a vaccine that is supposedly so effective having a breakout in the middle of the summer”; “antibody-mediated viral enhancement, that is a condition done when vaccines work wrong”; “no vaccine prevents you from getting infection”; “with vitamin D, ivermectin, and zinc [...] there is not a single person who has come anywhere near the hospital”; “people who have recovered from COVID-19 infection actually get no benefit from vaccination at all”


A viral Youtube video featured a speech by Daniel Stock, self-described as a functional family medicine physician, at a 6 August 2021 Board Meeting of the Mount Vernon Community School Corporation in Hancock County, Indiana. The video received more than 3,5 million views on YouTube alone. While YouTube removed the original video for violating the platform’s community guidelines, copies continue circulating on multiple media outlets and social media platforms, including Facebook, Instagram, and Twitter (see examples here, here, here, and here).

During the meeting, Stock claimed that the reason why we still have a problem with COVID-19 is because public health authorities’ recommendations are “contrary to all the rules of science”. He supported this claim with a flood of misinformation regarding COVID-19 transmission, vaccines, and treatment. Health Feedback and other fact-checking organizations covered these claims in earlier fact-checks, as we discuss in detail below.

Claim 1 (Misleading):

“Things you should know about coronaviruses and all other respiratory viruses is that they are spread by aerosol particles, which are small enough to go through every mask”

The main mode of COVID-19 transmission is thought to be contact with respiratory fluids carrying infectious virus. This doesn’t only occur in the form of aerosols, as Stock claimed, but also larger respiratory droplets, although the contribution of each mode to overall transmission is unclear. Face masks work primarily by reducing the amount of infectious liquid droplets and aerosols that an infected person disperses into the air (source control)[1]. In addition, face masks can protect the wearer mainly by forming a barrier to large respiratory droplets, but also filtering out part of the smaller particles[2].

Data about the effectiveness of community mask-wearing before the COVID-19 pandemic was scarce. However, many studies now demonstrate that community mask-wearing effectively reduces the spread of respiratory infectious diseases, contradicting Stock’s claim. The protective effect of face masks is higher when combined with other measures, such as frequent handwashing, adequate ventilation, and physical distancing. In this earlier review, Health Feedback summarized the scientific evidence supporting the effectiveness of mask-wearing in reducing the spread of coronaviruses, rhinoviruses, influenza, and SARS-CoV-2 in household and community settings[3-6].

Based on the available evidence, the U.S. Centers for Disease Control and Prevention (CDC) recommends community mask use as an effective way to reduce the spread of the virus.

Claim 2 (Inaccurate):

“The natural history of all respiratory viruses is that they circulate all year long waiting for the immune system to get sick through the winter or become deranged, as has happened recently with these vaccines”

Many infectious diseases have seasonal patterns with peaks of infection at certain times of the year that repeat every year. This disease seasonality pattern is exhibited by most respiratory viruses, including some common cold coronaviruses[7]. However, not all respiratory viruses are seasonal, nor do all seasonal viruses increase their activity during the winter season, as Stock claimed.

Winter viruses refer to viruses that cause a peak in the number of infections during the winter months, including influenza viruses, human coronaviruses, and the human respiratory syncytial virus. Most respiratory viruses are winter viruses. However, others like enteroviruses increase their activity in summer (summer viruses), and some like adenoviruses, human bocavirus, human metapneumovirus, and rhinoviruses are active throughout the year (all-year viruses)[8].

Claim 3 (Misleading):

“No one can make this virus go away […] Smallpox had no animal reservoirs. The only thing it learned to infect was humans, that’s why we were able to make that virus go away”

A reservoir is the environment or living organism where an infectious agent normally lives, grows, and multiplies. Animals often serve as reservoirs for infectious agents which can also infect humans, a process known as zoonosis.

Stock correctly points out that animal reservoirs constitute a major obstacle for eradicating SARS-CoV-2, the virus that causes COVID-19. The reason is that these animal reservoirs may keep introducing the virus into the population repeatedly. According to a Nature survey among more than 100 immunologists, infectious disease researchers, and virologists working on COVID-19, eradicating SARS-CoV-2 is “improbable”. Instead, 89% of them thought that the virus will likely become endemic, meaning that it will continue to circulate in some regions, maybe with a seasonal pattern.

But even if complete eradication is impossible, control measures, and particularly vaccination, can largely reduce the circulation of the virus and the threat it currently poses. Such is the case with other endemic diseases like influenza. According to the CDC, flu vaccines reduce the risk of flu illness between 40% and 60%, even though their effectiveness varies between seasons depending on the circulating strains.

All COVID-19 vaccines authorized for emergency use in the U.S. showed over 65% effectiveness against asymptomatic infection in real-world studies. Therefore, they are a very useful tool to limit the spread of the virus and prevent the risks associated with the disease.

Claim 4 (Misleading):

“And then ask yourself why is a vaccine that is supposedly so effective having a breakout in the middle of the summer, when respiratory viral syndromes don’t do that”

Stock suggested that COVID-19 vaccines are ineffective because some populations are experiencing COVID-19 outbreaks. He specifically cited a July 2021 study published in Morbidity and Mortality Weekly Report reporting a COVID-19 outbreak in Barnstable County, Massachusetts, in which 75% of the COVID-19 cases were detected among fully vaccinated individuals[9].

These cases are expected, and outbreaks like the one in Barnstable County don’t mean that COVID-19 vaccines are ineffective, as Full Fact explained in this fact-check. All three COVID-19 vaccines authorized by the U.S. Food and Drug Administration (FDA) are over 92% effective against severe disease and death. Furthermore, SARS-CoV-2 infections in fully vaccinated individuals are rare and tend to produce milder symptoms than in unvaccinated individuals[10,11].

Stock used an argument known as the nirvana fallacy, which consists in dismissing a solution because it is imperfect, even though no perfect solution exists. No vaccine, including COVID-19 vaccines, is 100% effective. Therefore, a small proportion of vaccinated people will still get infected and develop the disease.

Still, vaccinated individuals are less likely to get infected, hospitalized, and die compared to unvaccinated people. Therefore, while the proportion of infections among vaccinated people increases as this group becomes larger within a population, the proportion of serious illness and death decreases compared to a completely unvaccinated population. That is why most hospitalizations and deaths in the U.S. and other countries like the U.K. are now among unvaccinated people, as Health Feedback explained in earlier reviews here, here, and here.

Claim 5 (Unsupported):

“You need to know the condition that is called antibody-mediated viral enhancement, that is a condition done when vaccines work wrong, as they did in every coronavirus study done in animals on coronaviruses after the SARS outbreak”

This claim refers to a phenomenon known as antibody-dependent enhancement (ADE). ADE occurs when antibodies don’t block a virus from infecting cells, but instead improve its ability to infect them, increasing the risk of more severe disease when the individual gets exposed again to the virus. Contrary to what Stock claimed, this phenomenon isn’t exclusive to vaccines. Instead, it is a phenomenon that can affect any individual with preexisting antibodies, regardless if the antibodies arose as a result of vaccination or previous infection.

As Health Feedback explained in previous reviews, the claim that COVID-19 vaccines will cause ADE is unsupported by scientific evidence and actually contradicts the evidence. FDA-authorized COVID-19 vaccines haven’t shown signs of causing more severe disease in animal studies, clinical trials, or vaccination rollout in millions of people. In fact, as discussed above, all of them have proven highly effective in preventing severe disease, which is the opposite of what one would expect if ADE was occurring.

Claim 6 (Incorrect and Misleading):

“No vaccine prevents you from getting infection”

Vaccines are one of the most effective ways to protect individuals and communities from potentially harmful diseases and the risks associated with them. However, not all vaccines provide the same level of protection. While most vaccines only prevent symptoms or reduce disease severity, a few vaccines provide what is known as sterilizing immunity. The latter can completely block infection, preventing disease transmission to others. Examples of vaccines that induce sterilizing immunity are the vaccines against human papillomavirus and smallpox.

Therefore, the claim that no vaccine prevents infection is false. In fact, COVID-19 vaccines authorized in the U.S. are at least 65% effective against asymptomatic infection, as explained in Claim 3.

Furthermore, Stock’s claim is misleading because vaccines don’t need to completely stop transmission to control the spread of a disease. For instance, the introduction of the rotavirus vaccine in the U.S. in 2006 reduced the number of cases by 90%. Non-sterilizing vaccines have indeed proven to be invaluable tools for eliminating devastating diseases like polio from the U.S. and reduce the prevalence of many other diseases by 99%, including diphtheria, measles, mumps, and rubella[12].

Claim 7 (Unsupported and Misleading):

“I can tell you, having treated over 15 COVID-19 patients, that between active loading with vitamin D, ivermectin, and zinc, that there is not a single person who has come anywhere near the hospital”

This claim suggests that COVID-19 vaccines are unnecessary because there are available treatments for COVID-19, including vitamin D, ivermectin, and zinc. This is misleading because, in contrast to treatments, vaccines prevent the disease and the risks associated with it. Furthermore, none of these alleged treatments have proven effective in COVID-19 patients.

At the time of this review’s writing, there isn’t reliable evidence supporting any benefit of vitamin D or zinc supplementation for COVID-19 patients. The COVID-19 Treatment Guidelines from the U.S. National Institutes of Health (NIH) neither recommends the use of vitamin D and zinc for preventing or treating COVID-19 nor discourages it.

Some studies found an association between low vitamin D levels and a higher risk of infection and severe COVID-19, suggesting that vitamin D supplementation might benefit COVID-19 patients. As explained in earlier reviews by Health Feedback (see here, here, and here), maintaining an adequate vitamin D level is important for health, but data regarding the effectiveness of vitamin D supplementation at treating or preventing COVID-19—beyond the level needed to address deficiency—is still limited and conflicting and don’t support its use in COVID-19.

Likewise, studies evaluating the effectiveness of zinc supplementation for preventing or treating COVID-19 don’t provide sufficient evidence to support its use in COVID-19 patients[13-16]. Given the lack of a clear clinical benefit and the potential to cause toxicity, the NIH specifically recommends against using zinc supplementation beyond dietary recommendations, except in clinical trials.

Health Feedback addressed the claim that the antiparasitic drug ivermectin is effective against COVID-19 on several occasions (see here, here, and here) and found it unsupported. Multiple clinical trials evaluated the effectiveness of ivermectin in preventing and treating COVID-19. However, the evidence is inconclusive due to limitations of the studies, such as a small number of participants and poorly defined outcomes. For this reason, health authorities including the NIH and the World Health Organization, don’t recommend using ivermectin in COVID-19 patients outside of clinical trials.

A critical piece of evidence used by some to support the use of ivermectin for treating COVID-19 patients was a preprint by Elgazzar et al. The preprint was withdrawn in July 2021 due to ethical concerns after student Jack Lawrence uncovered numerous issues with the study, including plagiarism and potential data fabrication.

Claim 8 (Inaccurate):

“People who have recovered from COVID-19 infection actually get no benefit from vaccination at all”

As Health Feedback explained in this earlier review, COVID-19 vaccination can enhance protective immunity in previously infected individuals compared to those who remain unvaccinated. Recent scientific studies confirm it.

One study published in August 2021 in Morbidity and Mortality Weekly Report directly found that vaccination with any of the three COVID-19 vaccines authorized for emergency use in the U.S. reduced the likelihood of reinfection in previously infected individuals by 2.34 times[17].

In the U.K., an even more recent study published in Science Translational Medicine found that two doses of the Pfizer-BioNTech COVID-19 vaccine increased the immune response of previously infected individuals against the beta and gamma variants of the virus[18].


Stock’s speech rehashed numerous inaccurate, misleading, and unsupported claims that have been debunked many times before. Contrary to what Stock claimed in the video, community mask-wearing and vaccination are effective strategies to control the spread of the virus and the risks associated with COVID-19. Conversely, ivermectin and supplementation with zinc and vitamin D haven’t proven effective in preventing or treating COVID-19.



Published on: 13 Aug 2021 | Editor:

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