The role of Herpesviridae family in the development of long COVID

Objective. The aim of this study was to investigate the activity of viruses from the family Herpesviridae in leukocytes of patients with long COVID. Materials and Methods. Following a case-control design, the study included 52 patients with long COVID (Group 1). These patients were matched with "pairs" from those who had contracted COVID-19 and fully recovered within 3 months of disease onset (Group 2). The diagnosis of long COVID was established based on WHO criteria. Detection of Herpesviridae family antigens was performed by immunofluorescence using specific monoclonal mouse antibodies (MyBiosource, USA). Results. The Groups were comparable in terms of gender (32 women and 20 men in each Group) and age (52,6 ± 21,3 years vs 50,2 ± 20,6 years), p = 0,56. HSV 1, 2: there were 42 (80,8 %) patients with medium or high viral loads in Group 1 vs 16 (30,8 %) in Group 2, р < 0,0001. VZV: evaluation showed similar trends: 15 (28,8 %) patients had medium or high viral loads in Group 1 vs 4 (7,7 %) in Group 2, р = 0,006. EBV: fifteen (28,8 %) patients in Group 1 had medium or high viral loads vs 2 (3,8 %) in Group 2, р = 0,0006. CMV: twenty-five (48,1 %) patients in Group 1 had medium or high viral loads vs 3 (5,8 %) in Group 2, р < 0,0001. HHV 6: 25 (48,1 %) patients in Group 1 had medium or high viral loads vs 11 (11.5%) in Group 2, р < 0,0001. Conclusions. Our study provides valuable insights into the complex relationship between COVID-19 and Herpesviridae infections, offering a scientific basis for developing public health policies and interventions. Collectively, these findings suggest that latent viral infections should be considered a causal factor in long COVID. Screening and prevention programs for these conditions may be considered.