Informed consent to medical treatment is a right that ensures patients receive information about the recommended treatment so they can make a well-informed decision about their medical care.1 Medical practitioners are both ethically and legally obligated to ensure their patients have an opportunity for informed consent, which means disclosing both the risks and benefits of potential medical treatments.
In the case of the COVID-19 vaccine, it’s not possible to provide a full list of potential risks, considering the unprecedented speed with which they were developed and released to the public — the long-term effects are completely unknown.
Significant concerns have been raised, however, surrounding antibody-dependent enhancement (ADE), and the possibility that COVID-19 vaccines could worsen COVID-19 disease via ADE.2
Anyone receiving this experimental medical procedure would certainly want to be informed of its potential to worsen the very disease they’re trying to avoid, but it’s not included as part of the informed consent disclosure — despite researchers recommending back in October 2020 that it be “prominently and independently disclosed.”3
COVID-19 Vaccine Recipients Should Be Warned About ADE Risk
Writing in the International Journal of Clinical Practice, Timothy Cardozo of NYU Langone Health and Ronald Veazey with the Tulane University School of Medicine, noted, “Patient comprehension is a critical part of meeting medical ethics standards of informed consent in study designs.”4
As such, they set out to determine if enough research existed to require clinicians to disclose the specific risk that COVID-19 vaccines could worsen disease if the recipient is exposed to circulating virus. First, they reviewed preclinical and clinical evidence, which revealed that ADE is a significant concern. They noted:5
“COVID-19 vaccines designed to elicit neutralizing antibodies may sensitize vaccine recipients to more severe disease than if they were not vaccinated. Vaccines for SARS, MERS and RSV have never been approved, and the data generated in the development and testing of these vaccines suggest a serious mechanistic concern:
that vaccines designed empirically using the traditional approach (consisting of the unmodified or minimally modified coronavirus viral spike to elicit neutralizing antibodies), be they composed of protein, viral vector, DNA or RNA and irrespective of delivery method, may worsen COVID-19 disease via antibody-dependent enhancement (ADE).”
Their next step involved reviewing clinical trial protocols for COVID-19 vaccines to determine if this risk was properly disclosed to research subjects (at the time, the vaccines had not yet been released to the public). It was not, leaving people largely in the dark instead:6
“This risk is sufficiently obscured in clinical trial protocols and consent forms for ongoing COVID-19 vaccine trials that adequate patient comprehension of this risk is unlikely to occur, obviating truly informed consent by subjects in these trials.”
The conclusion reached by the study was that, in order to meet medical ethics standards of informed consent, people taking part in COVID-19 vaccine trials, as well as those who have received it after approval, should be clearly warned of the “specific and significant COVID-19 risk of ADE.”7
This, however, has not occurred, and most receiving it have likely not even heard of ADE, much less its association with the experimental COVID-19 vaccine.
What Is Antibody-Dependent Enhancement (ADE)?
When your body is exposed to a pathogen, it first ramps up a nonspecific response as part of your innate immune system. Next, your adaptive immune response takes over, generating neutralizing antibodies against the pathogen, which work to bind to the offender so it can’t enter your cells.
While vaccines may generate neutralizing antibodies, they can also induce binding antibodies, sometimes referred to as non-neutralizing antibodies, which increase the ability of a virus to enter your cells and worsen the disease.
Children’s Hospital of Philadelphia explained, “ADE occurs when the antibodies generated during an immune response recognize and bind to a pathogen, but they are unable to prevent infection. Instead, these antibodies act as a ‘Trojan horse,’ allowing the pathogen to get into cells and exacerbate the immune response.”8
It’s possible for pathogens to cause ADE, the most well-known being dengue virus, which has four different serotypes. If a person is infected with one serotype, neutralizing antibodies may effectively fight back against the disease.
However, if they’re exposed to a different serotype later, the neutralizing antibodies already circulating in their system can bind to the virus and enhance its entrance into cells, causing a severe form of the disease known as dengue hemorrhagic fever.9
Vaccinations are also known to cause ADE. In 1969, attempts to create a vaccination against respiratory syncytial virus (RSV) catastrophically failed after it led to increased rates of severe illness in infants. Eighty percent of vaccinated infants ended up hospitalized compared to only 5% of the nonvaccinated infants, and two vaccinated infants died due to enhanced RSV infections caused by the vaccine.10
RSV is an upper respiratory illness that is very similar to that caused by coronaviruses. In my May 2020 interview with Robert Kennedy Jr., he talked about the failed RSV vaccine:
“At the time, they did not test it on animals. They went right to human testing. They tested it on I think about 35 children, and the same thing happened. The children developed a champion antibody response, robust, durable. It looked perfect, and then the children were exposed to the wild virus and they all became sick. Two of them died. They abandoned the vaccine. It was a big embarrassment to FDA and NIH …”
An early version of the measles vaccine also resulted in ADE (measles belongs to the same family as RSV). Children who were vaccinated with the formalin inactivated measles vaccine were more likely to develop a severe, atypical measles infection, including high fever, unusual rash and pneumonia, leading the vaccine to be withdrawn from the market.11
Coronavirus Vaccines Linked to ADE
As Kennedy further noted, coronavirus vaccines remain notorious for creating ADE, or paradoxical immune enhancement. Coronavirus vaccine development, which began in 2002, followed three consecutive severe acute respiratory syndrome (SARS) outbreaks. SARS is caused by SARS-associated coronavirus, or SARS-CoV.
By 2012, Chinese, American and European scientists were working on SARS vaccine development and had about 30 candidates. Of those, the four best vaccine candidates were then given to ferrets, which are the closest analogue to humans with lung infections. In the video above, which is a select outtake from my full interview, Kennedy explains what happened next.
While the ferrets displayed robust antibody response, which is the metric used for vaccine licensing, once they were challenged with the wild virus, they all became severely ill and died, mirroring the severe effects that occurred during the failed RSV trials.
At the time, even long-time pro-vaccine advocate Dr. Peter Hotez, dean of the National School of Tropical Medicine and professor of pediatrics and molecular virology and microbiology at Baylor College of Medicine, was shaken. According to a feature published in PNAS:12
“When SARS, also a coronavirus, appeared in China and spread globally nearly two decades ago, Hotez was among researchers who began investigating a potential vaccine.
In early tests of his candidate, he witnessed how immune cells of vaccinated animals attacked lung tissue, in much the same way that the RSV vaccine had resulted in immune cells attacking kids’ lungs. ‘I thought, ‘Oh crap,’’ he recalls, noting his initial fear that a safe vaccine may again not be possible.”
According to Kennedy, the same thing happened in 2014 with the dengue vaccine DENVax. “They knew from the clinical trials that there was a problem with paradoxical immune response,” Kennedy says, but they gave it to several hundred thousand Filipino kids anyway.
They got a great immune response from the vaccine, but those exposed to wild dengue got horribly sick and 600 of the children died. “Today, the Philippine government is prosecuting criminally a bunch of the people locally who were involved in that decision,” Kennedy says.
Risk of ADE in COVID-19 Vaccines ‘Compelling’
The International Journal of Clinical Practice researchers called the risk of ADE in COVID-19 vaccines not only nontheoretical but also compelling.13 They noted that vaccine-elicited enhancement of disease has been previously found with SARS and Middle East respiratory syndrome-related (MERs) coronaviruses, as well as feline coronavirus, all of which are closely related to SARS-CoV-2, which causes COVID-19.
A 2019 study involving macaques and SARS14 raises additional concerns. According to the researchers:15
“Inflammation and tissue damage in the lung in this animal model recapitulated the inflammation and tissue damage in the lungs of SARS-infected patients who succumbed to the disease. The time course was also similar, with the worst damage occurring in delayed fashion in synchrony with ramping up of the immune response.
Remarkably, neutralizing antibodies controlled the virus in the animal, but then would precipitate a severe, tissue-damaging, inflammatory response in the lung. This is a similar profile to immune-complex mediated disease seen with RSV vaccines in the past, wherein vaccinees succumbed to fatal enhanced RSV disease due to the formation of antibody-virus immune complexes that precipitated harmful, inflammatory immune responses.
It is also similar to the clinical course of COVID-19 patients, in whom severe COVID-19 disease is associated with the development of anti-SARS-CoV-2 serum antibodies, with titers correlating directly with the severity of disease. Conversely, subjects who recover quickly may have low or no anti- SARS-CoV-2 serum antibodies.”
The goal of most COVID-19 vaccines is to produce neutralizing antibodies, and they believe that vaccine-elicited ADE is therefore likely to occur “to some degree” with COVID-19 vaccines.
“A finite, nontheoretical risk is evident in the medical literature that vaccine candidates composed of the SARS-CoV-2 viral spike and eliciting anti-SARS-CoV-2 antibodies, be they neutralizing or not, place vaccinees at higher risk for more severe COVID-19 disease when they encounter circulating viruses,” they explained.16
Current data on COVID-19 vaccines do not reveal a risk of ADE, but data are limited and studies have not been designed to follow what happens when subjects are exposed to circulating virus after vaccination, which is when ADE could occur.
“Thus,” the researchers added, “the absence of ADE evidence in COVID-19 vaccine data so far does not absolve investigators from disclosing the risk of enhanced disease to vaccine trial participants, and it remains a realistic, nontheoretical risk to the subjects.”17
True Informed Consent Is Required to Weigh Risks and Benefits
It’s often recommended that patients weigh the risks versus the benefits of medical procedures before making a medical decision. But this is only possible if informed consent provides an accurate picture of risk. In the case of COVID-19 vaccines, the researchers believe informed consent has failed:18
“Based on the published literature, it should have been obvious to any skilled medical practitioner in 2019 that there is a significant risk to vaccine research subjects that they may experience severe disease once vaccinated, while they might only have experienced a mild, self-limited disease if not vaccinated.”
Unfortunately, only minor risks such as injection site reactions, rare risks from the past or risks from unrelated vaccines and viruses are typically disclosed on vaccine trial informed consent forms. Further, generic statements about more severe systemic adverse events and death are the norm.
Given the strong evidence of ADE risk from COVID-19 vaccines, the researchers believe that a separate informed consent form should be given out to those receiving the vaccine, warning them of the specific risk of worsened COVID-19 disease from vaccination, and demonstrating consent that they understand this risk.19 If you received such a form, would it change your mind about getting the shot?