mRNA Vaccine Shrinks Deadly Childhood Cancer Tumors by 70%

Advance in the fight against cancer in kids

By Royal College of Surgeons in Ireland

Irish doctors move forward while Trump and RFK Jr.
push the US backwards by curtailing mRNA vaccines.

The success of mRNA vaccines during the COVID-19 pandemic sparked interest in whether the same technology could be harnessed to fight cancer. Researchers at RCSI University of Medicine and Health Sciences have taken an early step toward that goal, reporting the first preclinical evidence that an mRNA vaccine can target neuroblastoma, the deadliest childhood cancer.

Led by Dr. Olga Piskareva, Senior Lecturer in the RCSI Department of Anatomy and Regenerative Medicine, the team tested an mRNA vaccine delivered using peptide carriers. In preclinical models, the vaccine trained the immune system to recognize and attack neuroblastoma, delaying tumor development by 10 to 11 days and shrinking tumors by 70%.

Neuroblastoma is an aggressive cancer that develops from immature nerve cells and primarily affects infants and young children. Although treatments have improved over the years, high-risk and recurrent cases remain especially difficult to treat, and the disease is responsible for about 15% of all childhood cancer deaths. In Ireland, five to ten children are diagnosed each year, with roughly 80% of patients failing to respond meaningfully to current therapies.

Dr. Piskareva commented on the findings: “The mRNA vaccine technology is like LEGO bricks. By combining different bricks, we can tailor the vaccine to the individual needs with high precision. This pilot study indicates promising potential in the development of anticancer vaccines for neuroblastoma, offering new hope for children and families suffering from the disease. We are at the beginning of the mRNA vaccine development road, but the first milestone has been successfully completed”.

Nanoparticles target cancer cells

The vaccine was built using a new strategy based on tiny self-assembling particles called peptide nanoparticles. These particles are designed to target Glypican 2 (GPC2), a protein found on the surface of neuroblastoma cells.

Since GPC2 is also present in several other cancers, the same approach could potentially be adapted for a wider range of tumors, making it a notable step for future cancer immunotherapies.

Relapse remains the hardest barrier

When neuroblastoma returns after initial treatment, it is especially difficult to cure because the cancer often becomes resistant to existing therapies. Continued research into new treatment strategies, including the approach shown in this study, could help address that problem and may lead to better outcomes for people affected by neuroblastoma in the future.

Reference: “mRNA vaccination using peptide nanoparticles triggers a strong immune response against endogenous GPC2 in a murine neuroblastoma model” by Ellen King, Chayanika Saha, Rabia Saleem, Binyumeng Jiang, Eve O’Donoghue, Federica Cottone, Helen O. McCarthy and Olga Piskareva, 18 June 2026, Molecular Therapy Oncology.
DOI: 10.1016/j.omton.2026.201244