COVID-19 Vaccine Helps Fight Cancer?

Hello Summarians!

It is always amazing when an established medication or protocol is shown to have additional effects that were not anticipated. A tapeworm product helps with cancer, or a vaccine that enhances the effectiveness of other chemotherapy drugs?

Sometimes we need to suspend judgment and open our minds to new advances.

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New Bone Cancer Therapy

Osteosarcoma (OS) is the most common primary malignant bone tumor in children and young adults, with poor survival rates mainly due to pulmonary metastases and little progress in therapy over the past four decades. Standard treatment involves surgical resection and chemotherapy with methotrexate, Adriamycin, and platinum agents, which cause significant systemic toxicities. Niclosamide, an FDA-approved antihelminthic drug, has drawn attention as an anticancer compound because it disrupts pH gradients across cellular membranes and inhibits multiple cancer-promoting pathways—including Wnt/β-catenin, Akt/mTOR, JAK/STAT3, Notch, and NF-κB—while remaining relatively nontoxic to normal cells. However, its poor water solubility and extremely low oral bioavailability have limited its clinical use, as shown in a failed human prostate cancer trial. 

To overcome this limitation, researchers developed a niclosamide stearate prodrug therapeutic (NSPT), designed for intravenous administration as a nanoparticle formulation to bypass gastrointestinal absorption limits and prolong systemic circulation. Preclinical studies in both human and canine OS cell lines and murine models demonstrated antiproliferative, pro-apoptotic, and antimetastatic effects. Because naturally occurring canine OS is a well-established translational model for human OS—sharing biological behavior, histopathology, and treatment response—a first-in-dog feasibility trial was conducted to evaluate safety, pharmacokinetics (PK), and potential efficacy of the modified NSPT formulation (mNSPT). 

Scaling NSPT production for large animals required reformulating the nanoparticle composition to maintain stability and uniformity, yielding a preparation stable at 4 °C for at least a month. The study enrolled client-owned dogs with spontaneous OS receiving standard-of-care amputation and carboplatin chemotherapy. mNSPT infusions achieved consistent plasma exposure across dogs, suggesting a sustained-release depot effect of niclosamide in circulation. Despite limited sampling windows that precluded a full PK profile, postinfusion concentrations and two-hour area-under-the-curve values correlated with treatment exposure. 

Dogs treated with mNSPT plus carboplatin lived longer than historical controls treated with carboplatin alone. While standard carboplatin-treated dogs have a median disease-free interval of 327 days and a median overall survival of 383 days, dogs receiving the combination had median times to metastasis and overall survival of 510 and 632 days, respectively. Three dogs survived more than four years and died of unrelated causes, suggesting potential therapeutic benefit despite the small sample size. 

Adverse events included transient liver enzyme elevations, severe panting, and hyperthermia during infusions—symptoms reminiscent of mitochondrial uncouplers like 2,4-dinitrophenol, consistent with niclosamide’s mechanism of dissipating mitochondrial proton gradients and releasing energy as heat. One dog experienced life-threatening hyperthermia, establishing 10 mg/kg as the tentative maximum tolerated dose (MTD). Prophylactic diphenhydramine and meloxicam reduced these reactions. Rodent models did not show such toxicities, underscoring physiological differences relevant for dose translation. 

Overall, this first-in-dog feasibility study demonstrated that large-scale production and administration of mNSPT are achievable, safe within defined limits, and biologically active against OS. These results support further dose-optimization and efficacy studies in dogs to refine pharmacokinetics and toxicity profiles. The ultimate aim is to leverage canine comparative oncology data to inform human clinical trials for metastatic osteosarcoma, a disease that remains among the most treatment-resistant bone malignancies. 

Eward, W. C., Pavic, K., Spasojevic, I., Somarelli, J. A., Brighton, H., Cullen, M., Jung, S., Visgauss, J. D., Brigman, B. E., Needham, D., & Suter, S. E. (2025). Novel niclosamide stearate prodrug therapeutic shows potential efficacy against naturally occurring canine osteosarcoma in a clinical feasibility study. American Journal of Veterinary Research https://doi.org/10.2460/ajvr.24.06.0176 

Bottom line — Early results support this as a beneficial protocol.

Non-Anesthetic Dentals

Anesthesia-free dentistry (AFD), also called nonanesthesia dental cleaning, is commonly offered by groomers, retail stores, and sometimes veterinary clinics through outside contractors, even though many veterinary organizations—including the American Veterinary Dental College (AVDC), American Animal Hospital Association (AAHA), and the World Small Animal Veterinary Association (WSAVA)—have condemned the practice. Several regions, such as California, Nevada, and Ontario, legally restrict or forbid AFD unless performed under veterinary supervision. These positions are based on clinical experience and research showing that AFD fails to treat periodontal disease and can even worsen oral health. One study confirmed that dogs receiving AFD had worse periodontal outcomes, and there are concerns about the emotional stress and physical harm animals can suffer during these procedures. 

Many owners choose AFD because they fear anesthesia, yet studies show the risk of anesthetic-related death in healthy dogs and cats is extremely low—between 0.05% and 0.24%—and has decreased further with modern monitoring, preoperative exams, and training. In contrast, accurate diagnosis and treatment of dental disease require anesthesia for proper oral examination, probing, and imaging, such as dental radiographs or cone beam CT. Professional cleanings involve scaling and polishing both above and below the gumline, which prevents or stabilizes periodontal disease when done by trained personnel under anesthesia. 

Periodontal disease affects up to 90% of dogs by one year of age and, if untreated, can lead to tooth loss and serious local or systemic complications, including oronasal fistula, osteomyelitis, pathologic fracture, and even links to kidney, liver, cardiovascular, and brain disease. A colorimetric periodontal diagnostic strip test, which detects thiols produced by oral bacteria, offers a simple, noninvasive way to assess inflammation in conscious animals and can help convince hesitant owners to pursue appropriate anesthetized care. 

In this study, diagnostic strip scores aligned with the severity of disease found under anesthesia. Scores dropped significantly after professional dental cleaning and treatment, but AFD patients showed no such improvement. When compared, the periodontal disease levels were similar before treatment in both groups, but only anesthetized cleanings produced measurable health benefits. The findings confirm that AFD only removes visible supragingival calculus, offering cosmetic improvement without addressing subgingival infection or inflammation. Because subgingival plaque drives periodontal disease progression, cleaning only the visible surfaces is ineffective and may even delay necessary treatment by giving a false appearance of health. 

Additionally, AFD carries its own risks, including aspiration of debris, gingival injury, cervical fractures, and even death. The procedure lacks endotracheal intubation and adequate control over patient movement, increasing the danger of injury. Overall, the study reaffirms that AFD does not prevent or treat periodontal disease and may endanger animals. Only professional dental cleaning and therapy performed under general anesthesia provide effective, safe, and comprehensive oral care. 

Niemiec, B. A., Kangas, K. B., & Ribka, E. P. (2025). Anesthesia-free dentistry does not provide any demonstrable medical benefit for the control of periodontal disease in dogs. Journal of the American Veterinary Medical Association https://doi.org/10.2460/javma.25.06.0405 

Bottom line — Does not treat the condition well and may cause harm.

COVID-19 Vaccine and Cancer Therapy

The paper argues that standard COVID-19 mRNA vaccines can “wake up” the immune system in a way that helps cancer immunotherapy work better. In hospital records, patients with lung cancer or melanoma who got an mRNA COVID-19 shot within about 100 days of starting immune checkpoint inhibitors (ICIs) lived longer and, for melanoma, stayed progression-free longer. This benefit did not show up with flu or pneumonia vaccines, or with chemotherapy without ICIs. The advantage was seen across vaccine brands and doses, and even in patients whose tumors were “cold” at baseline—meaning they showed little PD-L1 and usually respond poorly to ICIs. 

Experiments in mice help explain why. The mRNA vaccine in lipid nanoparticles triggers a brief surge of type I interferon. That signal activates dendritic cells and other myeloid cells, which then present tumor antigens more effectively and prime tumor-killing CD8 T cells. Tumors react by increasing PD-L1, which can shut T cells down—so giving ICIs at the same time is key to keep the T cells active. Blocking the interferon pathway erased the benefit in mice, while blocking IL-1 did not. In healthy human volunteers, COVID-19 mRNA shots caused a short-lived spike in interferon and early activation of innate and T-cell markers, mirroring the mouse data. Clinically, tumors biopsied soon after vaccination showed higher PD-L1 scores, sometimes crossing thresholds that can change first-line treatment choices. 

Taken together, the study suggests a practical idea: use widely available mRNA vaccines, timed near ICI start, to temporarily reset the immune environment so ICIs work better. This could provide a low-cost bridge or complement to slow, personalized cancer vaccines, especially for patients with immunologically cold tumors. 

Grippin, A.J., Marconi, C., Copling, S. et al. SARS-CoV-2 mRNA vaccines sensitize tumours to immune checkpoint blockade. Nature (2025). https://doi.org/10.1038/s41586-025-09655-y 

Bottom line — Intriguing finding.

Just putting things in perspective …