COVID-19 Vaccine Improves Survival of Patients with Lung Cancer and Melanoma

“I’m about to tell you about a new medical study that may reshape the way we treat cancer in the coming years and decades. It’s a study that suggests that the mRNA COVID vaccines, those of Pfizer and Moderna fame, may improve survival in people with cancer receiving immunotherapy, and not by a small amount.”

F. Perry Wilson, MD, MSCE, Associate Professor of Medicine and Public Health, Yale School of Medicine

“The implications are extraordinary—this could revolutionize the entire field of oncologic care.”

Elias Sayour, MD, PhD, Pediatric Oncologist, University of Florida

As readers of Germ Gems know, I believe the development of vaccines is the most remarkable accomplishment in modern medicine. The COVID-19 vaccine is no exception. In this week’s post, I briefly review this vaccine’s extraordinarily fast development for the prevention of SARS-CoV-2 infection and also describe a surprising recent discovery: the COVID-19 vaccine also enhances immunotherapy against two really gruesome cancers, non-small cell lung cancer (NSCLC) and metastatic melanoma.

COVID-19 mRNA vaccines (a recap). The COVID-19 pandemic burst upon the scene in a seafood market in Wuhan, China in December 2019. By January 2020, the culprit, the coronavirus SARS-CoV-2, was isolated and characterized. By the end of that year, Pfizer and Moderna introduced mRNA COVID-19 vaccines that proved safe and highly effective.

The development of a new vaccine is a feat that ordinarily takes 10-15 years but “Operation Warp Speed,” a public-private partnership, accelerated the development, manufacturing and distribution of these mRNA COVID-19 vaccines. By August 2024, about 71% of the global population had received at least one dose of the COVID-19 vaccine, and an estimated 2.5 million lives were saved worldwide.

A spate of articles published in October 2025 highlights the durability of protection the COVID-19 vaccines provide. (See, e.g., Novak, S. “Annual COVID Vaccines Protect People against Severe Disease, Even with Prior Immunity, Scientific American, October 8, 2025; Cai, M., et al., “Association of 2024-2025 Covid-19 Vaccine Outcomes in U.S. Veterans,” New England Journal of Medicine, October 23, 2025; Du, Y., et al., “Durability of 2024-2025 COVID-19 Vaccines Against JN.1 Subvariants,” Journal of American Medical Association Internal Medicine, October 27, 2025).

COVID-19 mRNA vaccines also treat cancer. The ongoing success of mRNA COVID-19 vaccines in preventing SARS-CoV-2 infections is reassuring, but what really captured the medical news in October 2025 was the surprise finding that this vaccine also enhances the therapeutic benefit of PD-1-targeted checkpoint inhibitors, a mainstay of therapy of NSCLC and melanoma. The research of Adam Grippin, MD, PhD, and his colleagues at the University of Texas MD Anderson Cancer Center in Houston generated the excitement regarding the potential use of COVID-19 vaccines to treat NSCLC (lung cancer) and malignant skin cancer (melanoma). (Grippin, A.J., et al., “SARS-CoV-2 mRNA vaccines sensitize tumours to immune checkpoint blockade,” Nature, October 22, 2025; Jacobs, P., “A surprise bonus from COVID-19 vaccines: bolstering cancer treatment,” Science, October 20, 2025; Ingram, I., “Cancer Study Links COVID Shots to Longer Survival,” MedPage Today, October 20, 2025). Grippin and his colleagues found that mRNA COVID-19 vaccination within 100 days of initiating treatment with a checkpoint inhibitor was associated with higher 3-year survival rates compared with no vaccination (55.8% vs 30.6%, P<0.0001).

Preclinical work by the Grippin team demonstrated how mRNA vaccination can induce a surge of type I interferon-dependent immunity—priming T cells to infiltrate tumors (vaccination is associated with increased levels of PD-L1, a prime target of blockbuster immunotherapy with checkpoint inhibitor drugs). As only a fraction of patients respond to immunotherapy alone, this robust boost by COVID-19 mRNA vaccines suggested that the combination of a checkpoint inhibitor with COVID-19 vaccination will yield benefits to treatment-resistant disease. (Other investigators showed that no such association exists for flu vaccination.)

For their study, the Grippin team used institutional databases to retrospectively examine survival outcomes by mRNA COVID-19 vaccination status in a NSCLC cohort of patients and a separate cohort of patients with metastatic melanoma. Results were similar for both tumor types.

In his article “How the COVID Vaccine Could Help Treat Cancer,” Medscape, October 22, 2025, Dr. F. Perry Wilson provides an excellent discussion of the thinking behind this promising breakthrough in cancer treatment. As Dr. Wilson points out, cancer can be thought of as a failure of the immune system to eradicate an “enemy within,” that is, cancer cells. The synergistic effect of the COVID-19 mRNA vaccine, which is aimed at a viral enemy (SARS-CoV-2), plus a checkpoint inhibitor appears to be dependent upon the mRNA. In other words,  “it’s not what the vaccine targets that matters; it’s the fact that the vaccine contains mRNA.”

Grippin and his colleagues are planning prospective randomized clinical trials to formally investigate their findings regarding the use of mRNA vaccines to boost cancer immunotherapy. In the meantime, we can anticipate results of studies from animal models as well as work on the basic immunology underlying the phenomenon.

Back to SARS-CoV-2. It is exciting to see that the mRNA COVID-19 vaccines have potential as adjunctive cancer therapy. But these vaccines have already been proven to be highly effective and safe in fighting SARS-CoV-2.

This virus remains a very serious driver of hospitalizations and deaths. (Last year COVID-19 was listed as the primary cause of death on roughly 31,400 death certificates in the U.S.) Yet, COVID-19 vaccination rates in the U.S. are low. And the conflicting advice on COVID-19 vaccination provided by the Centers for Disease Control and Prevention these days is deemed likely to further reduce vaccination rates.

COVID-19 is beginning to surge globally. (Kavanagh, K., “COVID-19 Is Beginning to Surge Globally, Here’s What We Know,” Scientific American, November 5, 2025). Also, we have a new variant to worry about. (Gervais, J., “COVID: Is the ‘Frankenstein’ Variant Dangerous?” Medscape, October 7, 2025). ( It’s been dubbed ‘Frankenstein’ because it is a recombination of two subvariants). But there is a safe and effective vaccine that can protect you. So, please confer with your healthcare provider and get yourself vaccinated!