SARS-CoV-2 Reinfections and Long COVID in the Post-Omicron Phase of the Pandemic

Fotini Boufidou; Snežana Medić; Vicky Lampropoulou; Nikolaos Siafakas; Athanasios Tsakris; Cleo Anastassopoulou

doi:10.3390/ijms241612962

SARS-CoV-2 Reinfections and Long COVID in the Post-Omicron Phase of the Pandemic

Int J Mol Sci. 2023 Aug 19;24(16):12962. doi: 10.3390/ijms241612962.

Authors

Fotini Boufidou¹, Snežana Medić^{2

3}, Vicky Lampropoulou⁴, Nikolaos Siafakas⁵, Athanasios Tsakris⁴, Cleo Anastassopoulou⁴

Affiliations

¹ Neurochemistry and Biological Markers Unit, 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, 11528 Athens, Greece.
² Department of Epidemiology, Faculty of Medicine, University of Novi Sad, 21000 Novi Sad, Serbia.
³ Center for Disease Control and Prevention, Institute of Public Health of Vojvodina, 21000 Novi Sad, Serbia.
⁴ Department of Microbiology, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece.
⁵ Department of Clinical Microbiology, Attikon General Hospital, Medical School, National and Kapodistrian University of Athens, 12462 Athens, Greece.

Abstract

We are reviewing the current state of knowledge on the virological and immunological correlates of long COVID, focusing on recent evidence for the possible association between the increasing number of SARS-CoV-2 reinfections and the parallel pandemic of long COVID. The severity of reinfections largely depends on the severity of the initial episode; in turn, this is determined both by a combination of genetic factors, particularly related to the innate immune response, and by the pathogenicity of the specific variant, especially its ability to infect and induce syncytia formation at the lower respiratory tract. The cumulative risk of long COVID as well as of various cardiac, pulmonary, or neurological complications increases proportionally to the number of SARS-CoV-2 infections, primarily in the elderly. Therefore, the number of long COVID cases is expected to remain high in the future. Reinfections apparently increase the likelihood of long COVID, but less so if they are mild or asymptomatic as in children and adolescents. Strategies to prevent SARS-CoV-2 reinfections are urgently needed, primarily among older adults who have a higher burden of comorbidities. Follow-up studies using an established case definition and precise diagnostic criteria of long COVID in people with or without reinfection may further elucidate the contribution of SARS-CoV-2 reinfections to the long COVID burden. Although accumulating evidence supports vaccination, both before and after the SARS-CoV-2 infection, as a preventive strategy to reduce the risk of long COVID, more robust comparative observational studies, including randomized trials, are needed to provide conclusive evidence of the effectiveness of vaccination in preventing or mitigating long COVID in all age groups. Thankfully, answers not only on the prevention, but also on treatment options and rates of recovery from long COVID are gradually starting to emerge.

Keywords: COVID-19; ME/CFS; late sequelae; long COVID; long-haul COVID; pediatric long COVID; post-acute sequelae of SARS-CoV-2 infection (PASC); reinfection severity; vaccination benefits.

Publication types

Review

MeSH terms

Adolescent
Aged
COVID-19* / epidemiology
Child
Humans
Pandemics
Post-Acute COVID-19 Syndrome*
Reinfection
SARS-CoV-2

Grants and funding

This research did not receive external funding.