Understanding the role of COVID-19 vaccination in all-cause healthcare resource utilisation among adults with long covid in the Uk primary care setting: data from the 2022-2023 respiratory virus season

The role COVID-19 vaccination on healthcare resource utilization (HCRU) and cost remains unclear, especially during Omicron predominance and among high risk UK populations. A retrospective cohort study using UK The Health Improvement Network (THIN) primary care data included adults (≥18 years) with confirmed or suspected COVID-19 between September 2022- May 2023. Three cohorts were defined: Highest risk (eligible for two seasonal doses), High Risk (eligible for one dose), and All COVID-19 patients. Long COVID was identified as ≥ 1 symptom or diagnostic/referral code, ≥4 weeks post COVID-19 diagnosis. Inverse probability of treatment weighting assessed associations between vaccination status (yes/no and time since vaccination) and long COVID, HCRU, and costs. In both Risk Cohorts, COVID-19 vaccination was not associated with long COVID incidence. However, in the High Risk (<i>n</i> = 1,889) and All Patients cohorts (<i>n</i> = 8,507) outpatient specialist referrals were significantly lower in the 3–6-month post-vaccination group versus &gt; 6 months (rate ratio: 0.28; 95% CI: 0.10-0.79, <i>p</i> &lt; 0.05 and 0.46; 95% CI: 0.27-0.79; <i>p</i> ≤ 0.01, respectively) COVID-19 vaccination was not consistently associated with incidence of long COVID or all-cause HCRU. Findings suggest potential subgroup-specific benefits, highlighting the importance of annual vaccination. Further research with larger sample size and longer-term follow-up is warranted.