MRC Precision Prevention — Biological Mechanisms of Response Variation 2026: Up to £5 Million Per Project From a £15 Million Pot, With a Mandatory Expression of Interest Due 17 September 2026

MRC Precision Prevention — Biological Mechanisms of Response Variation 2026: Up to £5 Million Per Project From a £15 Million Pot, With a Mandatory Expression of Interest Due 17 September 2026

Prevention works, on average. That average is the problem this call is built around.

Statins, vaccines, weight-management drugs, immunological interventions — each one has a population-level effect size that hides enormous individual variation. Some people get most of the risk reduction. Some get very little. Some get the adverse effects without the benefit. The Medical Research Council’s position in this funding opportunity is blunt: the biological mechanistic pathways underpinning that variation are poorly understood, and relying on average effects across diverse populations produces suboptimal benefit, unnecessary treatment, and persistent health inequalities.

So MRC is putting £15 million behind human experimental studies designed to interrogate those pathways directly — not to infer them from observational data, but to perturb a biological system in people and measure what happens. The opportunity opened on 21 July 2026 and runs a mandatory expression of interest stage closing 17 September 2026 at 4:00pm UK time.

Key details

Note the overlap in the timeline: the full application window opens on 10 September, a week before the EOI window closes on 17 September. Full applications are by invitation only, so the practical sequence for you is still EOI first — but it means invitations move quickly and you should not treat mid-September as a rest period.

What MRC is actually funding

The scope statement sets two non-negotiable conditions. Your project must include an experimental intervention or challenge in humans, and it must focus on a mechanistic hypothesis. Everything else follows from those two sentences.

The framing is the shift from treatment to prevention in the 10-year NHS health plan for England. MRC connects that policy shift to a research gap: heterogeneity is commonly observed in response, risk reduction, adverse effects, and clinical outcomes associated with biomedical interventions, and nobody can currently explain most of it at a mechanistic level. The call asks for interventional studies in humans that validate a mechanistic hypothesis and directly interrogate the biology governing two things — the transition from health to early disease, and the variation in how people respond to biomedical prevention interventions.

The method MRC wants is deliberately specified: experimental challenges, interventions, or controlled perturbations, with measurable outcomes that provide evidence of the pathways involved. The contrast drawn in the call is with inferring pathways from observational data. If your design cannot perturb the system and observe the response, it is likely out of scope.

Four illustrative themes are listed, and MRC is explicit that they are non-exhaustive:

• Improving mechanistic understanding of how interventions modify biological pathways across different population groups, enabling more personalised and equitable prevention and avoiding harm.
• Generating mechanistic insights into early disease pathways that can support future development and tailoring of novel precision prevention approaches, and support stratification of populations.
• Using current treatment interventions as mechanistic tools to understand pathways influencing responsiveness to prevention interventions, informing stratified prevention.
• Validating surrogate endpoints that reflect the biological mechanisms underlying heterogeneity in response and track the health-to-disease transition — explicitly flagged as something that should not be the primary focus of an application.

Two areas get a named welcome: gaps in understanding biological mechanisms in multiple long-term conditions and in metabolic disease, and, where relevant, work in underrepresented populations.

What is out of scope — read this before you write anything

This call has an unusually long exclusion list, and most rejected applications will fail here rather than on quality. MRC will not support:

• Characterisation or phenotyping work aiming to elucidate disease aetiology, where that is the main aim and there is no experimental challenge or prevention intervention context.
• Experimental intervention or challenge in animals.
• Biomarker discovery projects. Exploratory biomarker studies are separately stated to be ineligible.
• Projects where the primary mechanistic question is about managing established disease rather than preventing onset — that is, tertiary prevention.
• Pre-clinical model development and validation.
• Development and evaluation of novel therapeutics, diagnostics, or devices (routed instead to UKRI Translation: MRC proof of concept).
• High-throughput screening approaches to target validation.
• Late-phase clinical efficacy trials (routed to MRC and the NIHR Efficacy and Mechanism Evaluation Programme).
• Observational studies involving no experimental challenge.

MRC points the first group of these towards its applicant-led schemes — the MRC research grant, new investigator research grant, and partnership grant — which is a useful signal. If your idea fits better there, it will not be rescued by reframing it for this call.

There is also a separate list of costs MRC will not fund at all: clinical studies designed to assess the safety or efficacy of treatments, PhD studentship costs, publication costs, and funding used as a bridge between grants.

Who can apply, and the demand management rules

The opportunity is open to organisations with standard UKRI eligibility. To apply you must be employed by an eligible research organisation and be able to show that you will direct the project and be actively engaged in the work.

For applicants without a contract of employment covering the full project, submitting an application constitutes a commitment by the research organisation that, if successful, contracts will be extended beyond the project end date and all necessary support will be provided — including mentorship and career development for early career researchers. That is a real institutional undertaking, not a formality, and your research office needs to see it early.

Demand management applies, and the rule is specific: a research organisation may lead or partner on more than one application, and applications may involve more than one organisation, but an individual may be project lead on only one application. There is no limit on the number of applications on which you can be a project co-lead. If two groups in your department are circling the same idea, resolve who leads before September rather than after.

Businesses and charity or third sector organisations cannot supply the project lead or a project co-lead, but can participate as project partners on an application led by an eligible UK organisation.

Because MRC is a lead funder here, international researchers can join as “project co-lead (international)”. Their intellectual contribution and added value must be clearly explained and justified in the Applicant and team capability to deliver section. Other international collaborators, and UK partners not at approved organisations, should be included as project partners.

The money, and how full economic costing shapes your budget

The total pot is £15 million. A single project can request up to £5 million full economic cost, and MRC funds 80% of FEC plus 100% of permitted exceptions. Arithmetically, that means a small number of large awards — plan accordingly, and be realistic about whether your study is a £1.5 million question or a £5 million one.

Eligible cost headings include a contribution to the salary of the project lead and co-leads, research and technical staff posts, research consumables, equipment, travel, data preservation, data sharing and dissemination, estates and indirect costs, and public partnerships including payments to public contributors.

Costs for work at international organisations by international project co-leads are funded at 100%. There is a cap: the total requested for international applicants from high income countries (those not on the OECD DAC list of ODA recipients), plus India and China, must not exceed 30% of the total resources requested. There is no cap on costs for applicants from DAC-listed development assistance countries. If your mechanistic work depends on a cohort or facility in, say, the United States or Germany, model that 30% ceiling into the budget from the start rather than discovering it at costing stage.

The two-stage process and what each stage is really for

Stage one — expression of interest. Mandatory. Submitted through the expression of interest precision prevention survey linked from the opportunity page, by 17 September 2026 at 4:00pm.

MRC is unusually candid about what happens to it: information provided at EOI will not be formally assessed. It is used to check remit and fit to scope, anticipate submission levels, and inform peer review and panel composition and membership. One caveat matters — in the event of high demand, MRC reserves the right to introduce shortlisting at this stage.

Read that as follows. The EOI is not a competitive proposal, but it is the document that determines whether a reviewer with the right expertise ever sees your science, and it is the document that could become a shortlisting instrument if the call is oversubscribed. Write it as if it will be assessed, because it might be.

Stage two — invited full application. Runs on the new UKRI Funding Service; Je-S is not accepted, so confirm your organisation is registered well before November. The window is 10 September to 5 November 2026. MRC will publish full details on how to apply, and the full assessment criteria, when that stage opens.

Assessment at stage two is by invited peer reviewers against the published criteria, followed by a panel that ranks applications and makes a funding recommendation. MRC makes the final decision. You will be notified of the outcome within 10 working days of the panel meeting and given feedback within eight weeks.

Milestones: a structural requirement, not a formatting detail

MRC states that experimental medicine awards will typically carry at least two milestones with defined success criteria, reflecting timely progression points and allowing mechanistic hypotheses to be laid out and assessed as the project moves forward. Milestones exist to mitigate risk and to make genuinely high-risk, innovative projects fundable.

At full application stage your milestones must give realistic timelines for regulatory steps, study team recruitment, participant recruitment, study completion, and data analysis. Success criteria should be SMART, with any robust go/no-go criteria spelled out.

The strongest piece of advice in the whole call is a single line: it is advisable to structure the project so that the critical questions are addressed as early as possible in the plan. A five-year design that only tests its central mechanistic hypothesis in year four is asking a panel to accept four years of unfalsifiable risk. Front-load the falsification.

How to prepare a competitive application

Name the gap, then name the consequence. Successful projects should address a clearly articulated gap in understanding either the mechanisms behind variation in response to preventive interventions or the biology of the health-to-early-disease transition — and have a clear pathway to informing the targeting, timing, or optimisation of precision prevention. Two moves, not one. A beautiful mechanistic question with no line to targeting or timing will read as basic science in the wrong competition.

Specify the readout before you specify the intervention. In all cases, relevant validated biological readouts must be measured to test the proposed mechanistic hypothesis. If your readout is not validated, you have a biomarker discovery project — which is ineligible.

Pick an intervention with an established safety profile. The call names pharmacological or immunological challenges as examples. A novel agent drags you into therapeutic development, which is out of scope and routed elsewhere.

Stay in the pre-disease window. Projects must focus on the pre-disease state, early stage, or emergence of disease. The moment your population is people with established disease being managed, you are in tertiary prevention and outside remit.

Address effectiveness, efficiency, and equity explicitly. MRC asks you to demonstrate how the insights could enhance all three, including by identifying opportunities to tailor interventions to the high-risk people and populations most likely to benefit. The equity dimension is not decoration here; it is tied to the call’s stated rationale about persistent health inequalities.

Engage your research office and regulators early. For costings and application writing, MRC’s guidance is to contact your research office first, allowing sufficient time for your organisation’s internal submission process. For a human experimental study, regulatory approvals are a milestone in their own right.

Common mistakes to avoid

• Submitting an observational study with an experimental veneer. No challenge or perturbation means no eligibility.
• Treating the EOI as administrative. It shapes the reviewer pool that will judge you, and can become a shortlist.
• Missing the EOI deadline and hoping to enter at full application. Full applications are by invitation only; the EOI is mandatory.
• Two colleagues each leading an application. You may lead only one.
• Building an international budget above the 30% ceiling for high income countries, India, and China.
• Making surrogate endpoint validation the centrepiece. The call permits it as a component and explicitly says it should not be the primary focus.
• Assuming Je-S. The full stage runs on the UKRI Funding Service and your organisation must be registered.
• Requesting ineligible costs — studentships, publication costs, or bridge funding — and forcing a costing rework late.

Frequently asked questions

Is the expression of interest optional? No. It is mandatory, and you must be invited before you can submit a full application.

Will my EOI be scored? Not formally. MRC uses it for remit checking, demand forecasting, and building the review panel — but reserves the right to shortlist at this stage if demand is high.

Can I be involved in more than one application? Yes, as a project co-lead on any number. As project lead, only one.

Can a company or charity lead? No. They can participate as project partners on an application led by an eligible UK organisation.

Can an overseas researcher be funded? Yes, as project co-lead (international), at 100% of eligible costs, subject to the 30% cap for high income countries, India, and China.

How long can the project run? Between three and five years.

What are the assessment criteria? MRC will publish the full criteria when the invited full application stage opens on 10 September 2026.

Is there guidance beyond the written call? Yes — MRC has published a recorded video for potential applicants covering the opportunity and frequently asked questions, linked from the Additional information section of the official page.

Official links and contacts

• Funding opportunity page: Expression of interest: Precision prevention: biological mechanisms of response variation
• Opportunity-specific queries: [email protected]
• General MRC funding and policy queries: [email protected]
• UKRI Funding Service helpdesk: [email protected], 01793 547490 (Monday to Thursday 8:30am–5:00pm, Friday 8:30am–4:30pm)

Sensitive information — a declaration of interest, a conflict for UKRI to consider in reviewer selection, unavailability due to parental leave, or the fact that an application is an invited resubmission — should go to [email protected] with the funding opportunity title and “sensitive information” in the subject line, rather than into the application body.

Next steps

If your group already runs human challenge or experimental medicine studies in a pre-disease population, this is a natural fit and the immediate task is choosing which single project you lead. If you do not currently hold the regulatory and recruitment infrastructure for an interventional human study, the realistic route into this £15 million is as a co-lead on someone else’s application — a position with no numerical limit attached.

Either way, the date that governs everything is 17 September 2026 at 4:00pm UK time. Miss it and there is no second door into the full application stage.