As US funding falters, mRNA cancer vaccine pioneers face new hurdles

Cuts to mRNA vaccine funding in the US have stalled infectious disease programmes, with experts warning the consequences are likely to extend to other promising therapeutic areas.  

It was only a matter of time before mRNA technology moved into the regulatory crosshairs of Robert F Kennedy Junior (RFK Jr). The health secretary has continually voiced his criticism of mRNA-based Covid-19 vaccines, questioning both their efficacy and safety.

In August, Dr Amesh Adalja of the Johns Hopkins University Center for Health Security in Baltimore told Pharmaceutical Technology that mRNA vaccines are being unfairly stigmatised by government agencies.

At the time, Dr Adalja anticipated that “it will only get worse.”

Indeed, it has. Changes to vaccine guidelines and recommendations overseen by RFK Jr have drawn criticism from senior leaders at the Centers for Disease Control and Prevention (CDC), but the severing of federal funding to mRNA projects was an abrupt wake-up call to the life sciences sector.

Risks to promising mRNA cancer vaccines

In August, RFK Jr cut $500m worth of mRNA vaccine research funding, impacting around 22 projects being run at the Biomedical Advanced Research and Development Authority (BARDA). Grants withdrawn were those for infectious disease vaccine candidates, with RFK Jr claiming the modality is ineffective against upper respiratory tract infections.

Vinay Prasad, director of the FDA’s Center for Biologics Evaluation and Research (CBER), has also been particularly outspoken against mRNA vaccines. Prasad said it was a “wise decision” to deprioritise mRNA vaccine technology research, citing unknown long-term safety and better alternatives.

It was a major setback for mRNA research & development (R&D), which has steadily grown in activity over the past eight years. When removing the anomaly of a significant uptick in 2021 amid Covid-19 vaccine research, the number of global mRNA vaccine trials initiated in 2024 was more than five times those started in 2017.

The US funding decision also impacted other mRNA-based technology initiatives run by the agency, such those showing promise in oncology.  Although still in relatively early-stage clinical trials, several vaccine candidates have shown efficacy in fighting pancreatic, prostate, and skin cancer, amongst others. Analysis by GlobalData indicates there are 232 clinical trials evaluating mRNA vaccines in oncology indications, a value far higher than any other therapeutic area excluding infectious diseases.

Prasad’s criticisms of mRNA vaccines do not stop at infectious diseases – he claims there is a “sea of negative findings” of the modality’s application in cancer. This contradicts the findings of recent early-stage trials evaluating several mRNA vaccines in various cancers. 

Regardless, Prasad’s views are especially pertinent, given that he heads up the department ultimately responsible for approving any future mRNA vaccine in a cancer indication.

Given the shared nature of the technology in infectious diseases and oncology, experts are concerned that the policy shifts could spread to this ongoing research with mRNA vaccines in cancer patients.  

“It will probably have an effect. What’s more concerning for me is just the fact that there is there seems to be a general attack on science in America. mRNA vaccines are a really promising technology, and it seems to have been shut down,” says Dr Shivan Sivakumar, associate professor at the University of Birmingham, which developing mRNA cancer vaccines.

Dr Sivakumar is principal investigator of an international, multicentre, randomised Phase II trial evaluating BioNTech’s mRNA vaccine BNT-122 as a preventative treatment option for pancreatic cancer.

“I think [the policy shifts in the US] are quite concerning because it’ll have an impact on the development of novel vaccination strategies against both infectious diseases and cancer,” Dr Sivakumar adds.

A US medical oncologist studying mRNA cancer vaccines agrees.

“There’s going to be some effects, obviously, because there’s this general title of mRNA vaccine research that’s tagged to it,” says Dr Jeff Yorio, lead trial investigator at Texas Oncology–Austin Central and one of the local sites leads for a global phase III trial testing Merck and Moderna’s mRNA vaccine candidate to prevent melanoma recurrence.

“Hopefully we continue focus on it and put resources behind it.”

Health secretary battles back

RFK Jr has defended his stance on mRNA vaccines. In a fiery Senate hearing on 4 September, he said he ‘agreed’ with a statement made by Dr Robert Malone that suggested mRNA vaccines cause serious harm and even death in young people.

Dr Malone is an anti-vaccine activist who has spread misinformation about coronavirus and associated vaccines. More recently, he blamed, without evidence, hospital error as the cause of recent paediatric deaths in children with measles, rather than the lack of immunisation against the disease. Dr Malone claims to have played an integral role in the creation of the mRNA vaccine, though Covid-19 experts have debunked this.

Meanwhile, there is no evidence to suggest mRNA vaccines cause ‘serious harm’ to young people. A 2025 study analysed 1 million individuals who received an updated mRNA Covid-19 vaccine containing the JN.1 lineage – a version that protects against most strains of the virus. The researchers found no statistically significant increase of recipients needing to go to hospital.

Dr Yorio says that safety aspects will need to be continually reviewed as the vaccine’s development in cancer accelerates, but maintains the modality is an area of high promise on the oncological spectrum.

“mRNA vaccines shifted into rapid production during Covid-19. But for oncology, it’s a much more complicated version of an infectious disease. Virus infections are mostly uniform. But the big problem with cancers is that everybody’s cancer is a little unique,” Dr Yorio explains.

Pharma unites amid political tension

With political attitude in the US shifting away from mRNA technology, other immunotherapeutic approaches are on standby to fill the potential void.

“It’s possible that that if other research focused on mRNA technology can’t advance in certain cancers, then other modalities may step into the gap,” says Paul Peter Tak, CEO of Candel Therapeutics, a biotech developing viral immunotherapies for several cancers.

Candel Therapeutics is not involved in developing mRNA vaccines, so Tak is confident the funding cuts and policy shifts won’t affect his company’s platform. However, he says treating patients is the end goal, and expresses concern that promising mRNA research is being stalled.  

“When I think about other companies that develop mRNA-based vaccines for cancer, I don’t see them as competitors but as colleagues meeting this incredible unmet need. I like companies to be set up for success,” adds Tak.

“There’s no doubt that mRNA technology has been a breakthrough in the world of vaccinations. I regret these decisions that have become politicalised.”

Tak’s remarks reflect a shared sentiment amongst many in the pharmaceutical industry who are concerned about the political attack on mRNA technology. Scientists on the frontline of research and executives of companies funding clinical candidates are unanimous in the promise mRNA vaccines have as an immunotherapy treatment avenue for cancers. Indeed, RFK Jr’s vaccine views have even drawn bipartisan criticism on Capitol Hill, with Republican and Democratic senators joining forces to uphold scientific integrity.

“In your confirmation hearings you promised to uphold the highest standards for vaccine. Since then, I’ve grown deeply concerned,” Republican Senator John Barrasso told RFK Jr during the senate finance committee hearing on 4 September.

“If we’re going to make America healthy again, we can’t allow public health to be undermined.”