Vaccine-Associated Enhanced Disease – Quercetin to the Rescue

Where are we with COVID-19? And what about vaccine-associated enhanced disease?

The BA.4.6 and BF.7 COVID variants have been slowly picking up steam in the United States. A few weeks ago, BQ.1.1 started to steal the spotlight.

Indeed, it still looks like a contender to take over in Europe and North America this fall. Finally, a lineage called XBB looms on the sidelines, according to the Washington Post. (The article is behind a paywall, but you can read it without subscribing here.) This variant threatens to scramble the forecast.

More Vaccines = More Infections

Vaccination was generally thought to correlate with decreased severity of symptoms. However, the authors of a recently published study in JAMA[1] found that when it came to Omicron infections, a third vaccine dose seven to 149 days prior to infection was associated with a higher likelihood of symptomatic infection compared with unvaccinated individuals (88.4% vs 79.4%; OR 2.0, 95% CI 1.1-3.5).

At the same time, these scientists reported that “COVID-19 symptoms associated with Omicron appeared to be milder and of a shorter duration than COVID-19 associated with Delta by many indicators.”

Viruses Mutate to Avoid Our Immune Defenses

This new paper is just one of thousands of peer-reviewed articles trying to make sense of vaccine-induced enhanced disease and literally COVID-19 variants and subvariants.

But what matters is that all these new threats are accumulating mutations in similar spots. These mutations occur in what’s called the receptor-binding domain. The receptor-binding domain is a key spot in the spike protein where virus-blocking antibodies dock. If those antibodies can’t dock, they can’t block the virus. So, each new mutation gives the virus a leg up in avoiding this primary line of immune defense.

The coronavirus spike protein is made up of about 1,300 building blocks called amino acids. Mutations that change even a single building block can make it harder for antibodies to block the virus.

Seeing so many lineages of the coronavirus develop similar constellations of genetic changes at these spots is a sign of convergent evolution when different versions of the virus have slammed into the wall of immune defenses in the human population, and then come up with similar ways to get around them.

We know that happens with influenza. But we’re just learning that it is fairly new to SARS-CoV-2. And in the case of the coronavirus, the more mutations, the bigger advantage a new variant seems to have to infect but not kill the host.

A New Variant Called XXB

XXB appears to be the best at evading immunity. Researchers in China have found that XXB can elude the protective antibodies generated by a breakthrough BA.5 infection, according to the Washington Post. This raises concern that the virus will be able to quickly outpace Fall boosters engineered to target the BA.4 and BA.5 versions of Omicron.

Hospitals Swamped with Kids Battling Non-COVID Respiratory Viruses

Almost three years after COVID-19 first arrived, doctors across the country are now sounding the alarm about surges in other types of respiratory illnesses, especially among children. These include RSV infections and sometimes deadly cases of the flu.

The percentage of emergency room visits from people with influenza-like illnesses is double what is typical for this time of year, according to some state data.[2]

So, why are respiratory infections rising among children? Could it be the COVID-19 mRNA vaccines?

Vaccine-Associated Enhanced Disease

I believe that multiple doses of COVID-19 vaccines can weaken innate immunity, especially in children. In other words, the COVID-19 vaccines themselves may be causing vaccine-associated enhanced disease.

The immune system is a complex network that needs to be trained and exercised. Innate antibodies and natural killer cells for this training and education are critical in children. This training must happen in order to build a robust immune system that can effectively ward off any and all infections on its own.

But our children’s immune systems were hobbled in their natural development because of pandemic lockdowns, masking, and social distancing. These measures likely hurt their immune systems, preventing the normal low-level exposure to bacteria and viruses that would have initiated immune responses for specific variants.

In addition, and perhaps as importantly, COVID-19 vaccines themselves may in fact prevent the innate B-cell antibodies from “educating” the cell-based innate immune system. The innate immune system includes T-cells and natural killer cells. T-cell immunity is broad and happens before the more specific B-cell antibody immunity.

Overusing mRNA vaccines may present a new problem: vaccinal neutralizing antibodies. Vaccine antibodies are highly specific and with greater affinity for the virus’s spike antigen. So, these antibodies can bind to the spike antigen and facilitate and enhance viral infectiousness. I am calling this vaccine-associated enhanced disease.

The neutralizing antibodies resulting from vaccination, set off immunological cascades in the host, which may further deteriorate the ’patient’s general medical condition. They also increase the risk of other viral infections in patients.[3]

Yet, despite this possibility, at the end of last month, the CDC voted unanimously to add COVID-19 shots to the pediatric schedule. At the same time, in many countries in Europe, the COVID-19 vaccines are not recommended for younger age groups. Even some of the most established medical doctors and research scientists are now speaking out in masse about safety issues when it comes to booster shots for young people. Indeed, some countries have suspended their vaccine programs. In addition, many African countries where mass vaccination was never implemented have enjoyed better health outcomes than in developed countries where vaccines and other COVID-mitigation measures, like lockdowns, were pushed.

Quercetin to the Rescue

But if you or your children have already been vaccinated against COVID-19 and you want to protect yourselves against vaccine-associated enhanced disease, I would argue that quercetin can help. Quercetin is a very potent mast cell stabilizing compound.

Quercetin is a plant pigment, or flavonoid. It is present in many foods.

These foods include:

  • Apples
    • Berries
    • Citrus fruits
    • Dark cherries
    • Grapes
    • Green tea
    • Olives
    • Onions
    • Parsley
    • Red wine
    • Sage

As I explain in this article, quercetin has potent immune-modulating effects and anti-viral compounds as well.

Indeed, quercetin is more effective than cromolyn in blocking human mast cell cytokine release.[4]

A Powerful Anti-Inflammatory

As an anti-inflammatory, antioxidant, analgesic, and inflammatory compound, quercetin is a potential treatment for severe inflammation.

Remember that inflammation is one of the main life-threatening conditions in patients who suffer from severe cases of COVID-19.

Molecular Mechanisms of Quercetin Action to Manage COVID-19[5]

As I explain in more detail in my other article, quercetin inhibits the ability of viruses to infect cells, inhibits replication of cells that are already infected, and reduces the resistance of infected cells to antiviral treatments.

I recommend you add quercetin-rich foods to your daily diet, take a quercetin supplement, and also consider consulting a naturopathic doctor or other healthcare practitioner who can give you advice about tailoring quercetin to your individual genetics and health needs.

About the Author

Donald R. Yance is the founder of the Mederi Center. A Clinical Master Herbalist and Certified Nutritionist, Donnie is renowned for his extraordinary knowledge and deep understanding of the healing properties of plants and nutrition, as well as of epigenetics, laboratory medicine, oncologic pathology, and molecular oncology. He is a professional member of the American Herbalists Guild, National Association of Nutrition Professionals, Academy of Integrative Health and Medicine, and the Society for Integrative Oncology. He is also the author of the book, Adaptogens in Medical Herbalism: Elite Herbs and Natural Compounds for Mastering Stress, Aging, and Chronic Disease.


[1] Fowlkes AL, et al “Association of mRNA vaccination with clinical and virologic features of COVID-19 among US essential and frontline workers” JAMA 2022; DOI: 10.1001/jama.2022.18550.

[2] By Jane Doe, North Carolina Health News, October 22, 2022;

 Creative Commons Attribution-NoDerivatives 4.0 International License.

[3] Ali T, Mujawar S, Sowmya AV, Saldanha D, Chaudhury S. Dangers of mRNA vaccines. Ind Psychiatry J. 2021 Oct;30(Suppl 1):S291-S293. doi: 10.4103/0972-6748.328833. Epub 2021 Oct 22. PMID: 34908713; PMCID: PMC8611574.

[4] Weng Z, Zhang B, Asadi S, Sismanopoulos N, Butcher A, Fu X, Katsarou-Katsari A, Antoniou C, Theoharides TC. Quercetin is more effective than cromolyn in blocking human mast cell cytokine release and inhibits contact dermatitis and photosensitivity in humans. PLoS One. 2012;7(3):e33805. doi: 10.1371/journal.pone.0033805. Epub 2012 Mar 28. PMID: 22470478; PMCID: PMC3314669.

[5] Saeedi-Boroujeni A, Mahmoudian-Sani MR. Anti-inflammatory potential of Quercetin in COVID-19 treatment. J Inflamm (Lond). 2021 Jan 28;18(1):3. doi: 10.1186/s12950-021-00268-6. PMID: 33509217; PMCID: PMC7840793.

   Send article as PDF   

3 Replies to “Vaccine-Associated Enhanced Disease – Quercetin to the Rescue

  1. Another great post, Dr Yance. Thank you for your tireless efforts to bring sense to the madness engulfing people everywhere. I only hope that more and more people will become familiar with your work as it may indeed result in many unnecessary deaths and severe illnesses being averted. Bravo! I will now forward this post to everyone I know. Be safe, be strong, and have a wonderful Christmas!

  2. Up to the minute, life-saving information, Donnie. Well done. I especially appreciate that your focus is on foods. People think that just because they take a certain vitamin, or multiple, etc. that diet does not matter, but according to my own research as a health/cooking author, food has never mattered more!

  3. Thank you Donnie – once again, extremely helpful information.
    A while back (well over a year ago now) you did a review of other vaccine options – one in particular was Novavax – which I believe is a protein subunit instead of mRNA. Novavax is available in Jackson County now – just curious what your current thinking is on this vaccine.

Leave a Reply

Your email address will not be published. Required fields are marked *