# The self-experiment: a virologist treated her own recurrent breast cancer with two viruses she made in her own laboratory

Source: https://onco.cc/key-papers/paper-halassy-self-experiment-ovt-vaccines-2024/  
OnCo record `paper-halassy-self-experiment-ovt-vaccines-2024` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A virologist whose breast cancer had come back and grown into the chest muscle injected it herself with a measles vaccine strain and then a second virus, the tumour shrank enough to be removed by simple surgery, and she was free of recurrence more than three years later.

## Summary

Case report of a 50-year-old woman with locally recurrent, muscle-invasive breast cancer who was also a virologist, and who treated the tumour herself with intratumoural injections of research-grade virus preparations made in her own laboratory before having any other treatment for the recurrence.

The history: multifocal invasive ductal triple-negative breast cancer diagnosed in 2016, treated with mastectomy and adjuvant chemotherapy; a small local recurrence excised in 2018, leaving a seroma under 1 cm that was monitored; by 2020 that had become a 2 cm solid, hard, inflamed nodule. Magnetic resonance imaging, positron emission tomography with computed tomography and two independent ultrasound estimates all gave a volume of 2.47 plus or minus 0.06 cm3, with invasion into the pectoral muscle and infiltration of the skin, and no evidence of metastatic or nodal disease. A baseline core biopsy showed the tumour had changed phenotype from triple-negative to HER2 3+.

The protocol: seven injections of an Edmonston-Zagreb measles vaccine strain at three to four day intervals over three weeks, then three injections of a vesicular stomatitis virus Indiana strain separated by two weeks and one week, then surgical excision. Two months after excision, one subcutaneous dose of measles virus was given around the surgical suture. Totals were 7.89 log CCID50 of measles virus and 9.07 log CCID50 of vesicular stomatitis virus, given multifocally in 1 to 2 mL. Neither virus had been engineered to improve its oncolytic properties; the preparations were clarified cell culture supernatants grown in MRC-5 and Vero cells, not purified from host-cell nucleic acid and protein.

The outcome: the tumour transiently swelled to 4.28 cm3 by day 8 and to 2.17 cm3 on day 41 after the first vesicular stomatitis virus dose, then shrank; the excised tumour measured 0.91 cm3 pathologically. It was confined to the subcutis with no skin or muscle infiltration, in contrast to baseline. Lymphocyte infiltration rose from 10 to 45 per cent, CD20-positive B cells from 10 to 70 per cent, CD8-positive T cells from 30 to 60 per cent, macrophage infiltration increased, and PD-L1 became detectable in a tumour that had been PD-L1 negative. Neutralising antibody titres to both viruses were low but measurable at baseline and rose a hundredfold. The only systemic adverse event was fever and rigors twelve hours after the first vesicular stomatitis virus dose, resolving over three days; injections were painful at first. Because the excised tumour was HER2 3+ she completed one year of adjuvant trastuzumab, and was recurrence-free 45 months after surgery, against previous recurrence intervals of 22 and 21 months.

On ethics, the authors state that as a case of self-experimentation it does not require ethics committee review, that the patient was fully informed and consented, and that her oncologists agreed to monitor and to intervene with conventional therapy if there were adverse effects or progression. Their conclusion states plainly that self-medicating with oncolytic viruses should not be the first approach to a diagnosed cancer, and asks instead for formal clinical trials of the neoadjuvant setting. The senior author disclosed becoming a consultant to Vyriad in 2021, and a European patent application covering the subject matter.

## Fields

- Kind: Key paper
- Last checked: 2026-09-25
- Journal: Vaccines
- Year: 2024
- DOI: 10.3390/vaccines12090958
- Authors: Forcic D, Mrsic K, Peric-Balja M, Kurtovic T, Ramic S, Silovski T, Pedisic I, Milas I, Halassy B
- Findings: Seven intratumoural doses of an Edmonston-Zagreb measles vaccine strain over three weeks, then three doses of a vesicular stomatitis virus Indiana strain, totalling 7.89 log CCID50 of measles virus and 9.07 log CCID50 of vesicular stomatitis virus.; Tumour volume fell from 2.47 plus or minus 0.06 cm3 at baseline, by four independent imaging estimates, to 0.91 cm3 measured pathologically in the excised specimen, after transient swelling to 4.28 cm3 on day 8.; The excised tumour was confined to the subcutis with no skin or pectoral muscle infiltration, in contrast to the baseline imaging, so a simple non-invasive resection was possible.; Lymphocyte infiltration rose from 10 to 45 per cent; CD20-positive B cells from 10 to 70 per cent; CD8-positive T cells from 30 to 60 per cent; macrophage infiltration increased; PD-L1 became detectable in a previously PD-L1-negative tumour.; Neutralising antibody titres against both viruses were low but measurable at baseline and rose a hundredfold during treatment.; The only systemic adverse event was fever and rigors twelve hours after the first vesicular stomatitis virus dose, resolving over three days.; The tumour had changed phenotype from triple-negative at first diagnosis to HER2 3+ on the baseline biopsy, so one year of adjuvant trastuzumab was given after surgery; the patient was recurrence-free 45 months after surgery.
- What it means: One person, one tumour, one report, and it is not evidence that anyone should treat themselves. What it does contribute is unusually well documented: serial imaging through the course, a baseline biopsy and an excised specimen scored by the same pathology department, antibody titres, and a named protocol with doses. The design choices are the interesting part. Two different viruses in sequence to stay ahead of the antiviral antibody response, frequent dosing to keep infectious virus concentrated in the tumour, and the neoadjuvant setting rather than the late metastatic setting in which oncolytic viruses are normally tested. The result also cannot be attributed to the viruses alone: the tumour was surgically removed and a year of trastuzumab followed, and the phenotype change to HER2 3+ is itself a plausible reason the disease behaved differently this time.
- Caveats: A single case, uncontrolled, in a patient with exceptional expertise and access; it establishes nothing about efficacy.; The tumour was excised and one year of trastuzumab followed, so the 45-month recurrence-free interval cannot be attributed to the viruses.; The tumour had converted from triple-negative to HER2 3+, a change that by itself alters both prognosis and treatment options.; The virus preparations were research grade, unpurified clarified cell-culture supernatants containing host-cell nucleic acid and protein, so the biological agent was not the virus alone.; Neither virus was engineered for tumour selectivity; wild-type vesicular stomatitis virus is considered potentially neurotoxic in humans and the authors call for neurotoxicity studies before any development.; The authors' own conclusion states that self-medication with oncolytic viruses should not be a first approach to a diagnosed cancer.; Declared interests: the senior author became a consultant to Vyriad in 2021 and the work is the subject of a European patent application.

## Sources

- Vaccines 2024 (open access): https://doi.org/10.3390/vaccines12090958
- PubMed: https://pubmed.ncbi.nlm.nih.gov/39339989/
- Europe PMC: https://europepmc.org/article/MED/39339989
- Europe PMC full text: https://europepmc.org/articles/PMC11435696

## Connected records

- key papers: [Bourgeois-Daigneault 2018: giving the virus before surgery, not after everything else has failed](https://onco.cc/key-papers/paper-bourgeois-daigneault-neoadjuvant-ovt-tnbc-scitranslmed-2018/), [Pugh 2026: should a journal publish a scientist's experiment on herself?](https://onco.cc/key-papers/paper-pugh-self-experimentation-publication-jme-2026/)
- cancers: [HER2-positive breast cancer](https://onco.cc/cancers/breast-her2-positive/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- fronts: [Immunotherapy](https://onco.cc/fronts/immunotherapy/)
- technologies: [Oncolytic viruses](https://onco.cc/technologies/oncolytic-virus/)
- drugs: [Trastuzumab](https://onco.cc/drugs/trastuzumab/)
- people: [Beata Halassy](https://onco.cc/people/beata-halassy/), [Dubravko Forcic](https://onco.cc/people/dubravko-forcic/)

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