Unravelling Sex-Specific Mechanisms Underpinning Long COVID: An Integrative Epidemiological and Biomarker-Based Investigation of Women’s Disproportionate Burden (Ref: SSEHS/SF-MF26-2)

About the Project

Long COVID (post‑COVID condition) is a chronic, multisystem disease state that persists for ≥3 months after SARS‑CoV‑2 infection and impairs dailyfunctioning for many sufferers. Women consistently show higher prevalence and activity limitation than men, yet the drivers, biological (immune, autonomic, endocrine), and social, are not resolved. Large, contemporary cohorts (e.g., NIH RECOVER) report a ~31% higher risk of Long COVID in females—with age, pregnancy, and menopausal status shaping risk— underscoring the need for mechanistic, sex‑aware research and clinical translation. UK statistics similarly show higher self‑reported prevalence and greater activity limitation among women, highlighting societal and economic burdens. Mechanistically, converging evidence points to immune dysregulation (including altered monocyte/B‑cell states and low cortisol), autonomic dysfunction (e.g., orthostatic tachycardia/POTS), and endocrine perturbations, with plausible hormonal modulation of immune pathways.

Recent multi‑omic analyses suggest sex‑specific immune correlates and sustained inflammatory signalling in Long COVID, but integrated models linking symptoms to objective biomarkers across systems are rare. This project will execute a three‑part programme:

1. survey/databank analyses to quantify sex differences in Long COVID phenotypes, symptom clusters, and functional impact;
2. a lab‑based and ambulatory tracking study to profile immune, autonomic, and endocrine markers in a sex‑stratified cohort;
3. multimodal integration to align symptom trajectories with objective biomarkers and develop predictive signatures.

Outputs will delineate sex‑specific mechanisms, inform clinical triage (e.g., POTS screening), and identify candidate therapeutic targets, advancing both mechanistic insight and service design for women’s health in infection‑associated chronic illness.

Project Aims:

1. Quantify sex differences in Long COVID prevalence, symptom clusters, and functional/occupational impact using survey and databank mining.
2. Characterise multi‑system biomarkers (immune, autonomic, endocrine) associated with Long COVID, with deep phenotyping in women.
3. Integrate symptoms with objective markers to build sex‑aware predictive models of severity and trajectory.
4. Map plausible mechanistic pathways (e.g., hormonal modulation of immune/autonomic axes) that could explain women’s disproportionate burden and suggest targeted interventions.

Proposed Studies

1. Population & Survey Analytics. Design: Cross‑sectional and longitudinal analyses from existing cohorts + new online survey. Outcomes: Sex‑stratified prevalence, symptom clusters (latent class), activity limitation; risk models incorporating socio-demographics and comorbidities.
2. Mechanistic Cohort (Lab + Tracking). Sample: n≈220 (≈70% women), four groups (female LC, male LC, female recovered, male recovered), matched by age/time‑since‑infection. Measures: Immune panels, EBV serology, cortisol diurnal, sex steroids; HRV, four‑week wearables; symptoms; menstrual/menopausal data.
3. Multimodal Integration. Analytics: Late‑fusion models (GBM/elastic net), SEM for mechanistic pathways; internal validation with bootstrap optimism correction; subgroup discovery for sex‑specific endotypes.

Supervisors

• Primary supervisor: Mark Faghy
• Secondary supervisor: Dr Emma O'Donnell

Entry requirements

The minimum criteria for Doctoral study are an upper second class bachelor degree or equivalent qualifications and experience, together with an English Language qualification. A degree or equivalent qualifications and experience are preferable in the areas of health, science, and public health.

Applicants must meet the minimum English language requirements.

Fees and funding

Tuition fees for 2026-27 entry

• UK fee - £5,238 Full-time degree per annum
• International fee - £29,500 Full-time degree per annum

Fees for the 2026-27 academic year apply to projects starting in October 2026, February 2027 and July 2027.

Bench fee value: £20,000

Start date: October 2026, February 2027, July 2027

Application deadline: 18 December 2026

Duration: Full-time 3 years / Part-time 6 years

How to apply

All applications should be made online. Under Campus, please select Loughborough and select Programme Sport Excerise and Health Sciences. Please quote the advertised reference number SSEHS/SF-MF26-2 in your application.

To avoid delays in processing your application, please ensure that you submit the minimum supporting documents. The following selection criteria will be used by academic schools to help them make a decision on your application.