COVID-19 vaccination influence on developing Long Covid

Summary: Comparing Long Covid symptoms between patients that received COVID-19 vaccinations and those that did not.

Study by Pasculli et. al., (2025) summarised by Amanda Harrington-Vail

Introduction

Since the COVID-19 pandemic was officially declared, almost 780 million cases and nearly 7 million deaths have been reported worldwide. Although COVID-19 vaccination has reduced the risk of severe illness, vaccinated people can still be infected and experience symptomless, mild, or moderate forms of disease. While most patients recover within a few weeks, some experience effects long after their initial COVID-19 infection, whether they were hospitalised or not. This was a retrospective study of patients who received medical care at the Sapienza University of Rome. A total of 582 patients were included between May 2020 and February 2024, comprising 272 women and 310 men aged 49–66 years. All patients had experienced no more than one confirmed COVID-19 infection and were either fully vaccinated, partially vaccinated, or unvaccinated. Long Covid symptoms were self-reported and assessed alongside patient characteristics, then grouped into symptom categories. The most commonly reported Long Covid symptoms in this study were ongoing fatigue, shortness of breath, altered taste and smell, heart-related symptoms, and difficulties affecting memory, concentration, mood, or emotional wellbeing. All patients were examined at a Long Covid clinic by a multidisciplinary medical team.

Summary

Clinical assessments included lung function testing, a six-minute walking test, chest CT scans, blood pressure measurements, ECG monitoring, and blood tests, including assessment of COVID-19 antibodies. Of the 582 participants, 373 were hospitalised during their acute COVID-19 infection, while 209 managed their illness at home. More women in this study were vaccinated than men, and there was no meaningful age difference between vaccinated and unvaccinated participants. Neuropsychiatric symptoms (including difficulties with brain function, emotion, and mood) were reported more frequently among unvaccinated outpatients compared with vaccinated outpatients. Unvaccinated patients also showed higher rates of skin disorders and secondary infections. Cardiac assessments showed a higher proportion of abnormalities in unvaccinated patients compared with vaccinated patients.

Conclusion

Vaccinated patients were less likely to have been hospitalised during their acute COVID-19 infection and were less likely to require invasive breathing support. COVID vaccination was associated with fewer long-term changes in heart and lung function, as well as less evidence of lasting lung damage on CT scans. This study did not find an association between vaccination status and the development of at least one Long Covid symptom overall. However, it observed a higher frequency of neuropsychiatric symptoms, skin disorders, and cardiac changes among unvaccinated patients. As this was a retrospective study based on clinic attendees and largely self-reported symptoms, the findings show associations rather than cause and effect. Further research using standardised symptom definitions and methodologies may help improve understanding of how Long Covid symptoms develop.

Read the full study here