The impact of vaccination status on post-acute sequelae in hospitalized COVID-19 survivors using a multi-disciplinary approach: An observational single center study

Abstract

Background: COVID-19 vaccines reduced mortality, hospitalizations and ICUs admissions. Conversely, the impact of vaccination on Long COVID-19 syndrome is still unclear. This study compared the prevalence of post-acute sequelae at short and long-term follow-up among hospitalized unvaccinated and vaccinated COVID-19 survivors through a multidisciplinary approach.

Methods: After 2 months from discharge, unvaccinated and vaccinated COVID-19 survivors underwent a follow-up visit at a dedicated "post-COVID-19 Outpatient Clinic". The follow-up visit included a cardiovascular evaluation, blood tests, chest computed tomography, 6-min walking test (6MWT), spirometry. A one-year telephone follow-up was performed to assess re-hospitalizations, death and long-lasting symptoms. An additional 1:1 case-control matching analysis adjusted for baseline characteristics was performed.

Results: Between June 2020 and June 2022, a total of 458 unvaccinated and vaccinated patients (229 per group) underwent the follow-up visit. Vaccinated patients had lower rates of ICU admissions (1.7 % vs 9.6 %, p= <0.001) and severe respiratory complications requiring intubation (1.3 % vs 7 %, p = 0.002) or non-invasive ventilation such as high-flow nasal oxygen therapy (1.7 % vs 7.9 %, p = 0.02), CPAP (1.3 % vs 20.1 %, p= < 0.001), and low-flow oxygen therapy (3.5 % vs 63.3 %, p= <0.001) compared to unvaccinated ones. At 2-month follow-up, vaccinated patients had fewer persistent ground-glass opacities (2.6 % vs 52.8 %, p= <0.001) or consolidations (0.9 % vs 8.3 %, p= <0.001). Additionally, unvaccinated patients experienced more frequent myocarditis (4.8 % vs 0.9 %, p = 0.013) and pulmonary embolism (1.8 % vs 0 %, p = 0.042) and exhibited more significant respiratory impairment as evidenced by desaturation during the 6MWT(10.2 % vs 3.5 %, p = 0.005) and altered spirometry (14 % vs 8.7 %, p = 0.043) compared to vaccinated ones. At one-year, unvaccinated patients reported more symptoms such as dyspnea (20.5 % vs 10 %, p = 0.002), psychological symptoms (10 % vs 3.5 %, p = 0.005) and chronic rhinosinusitis/cough (6,6 % vs 2,6 %, p = 0.04) as compared to vaccinated ones. The 1:1 case-control matching analysis also confirmed these results.

Conclusions: COVID-19 vaccines improve short-term outcomes and may reduce Long COVID-19 prevalence.

Keywords: Hospitalized; Long-COVID19; Sequalae; Survivors; mRNA vaccines.

Fig. 1

Protocol of the study.

Fig. 2

Example of myocarditis at 2 months follow-up visit. A 60-year-old male patient presented at follow-up visit in NYHA class II and new onset of severe ventricular disfunction. The patient underwent coronary angiography revealing unobstructed coronary arteries (A,B,C) and Cardiac Magnetic Resonance suggestive of acute myocarditis, according to Lake Louis' criteria (D,E,F,G,H).

Fig. 3

Incidence of cardiovascular events at 2 months follow-up. Unvaccinated patients experienced more frequent myocarditis and pulmonary embolism.

Figs. 4

2 months CCT. Persistent ground-glass opacities or consolidations were more frequent in unvaccinated patients as compared to vaccinated ones.

Fig. 5

Long-lasting symptoms at 1 year phone call follow-up. Unvaccinated patients reported more frequent long-lasting symptoms such as dyspnea, psychological symptoms and chronic rhinosinusitis/cough as compared to vaccinated ones.