Abstract
Background: Long COVID is a condition characterized by long-term sequelae persisting after the typical convalescence period of COVID-19. Previous reports have suggested the role of an unsatisfactory immune response and impaired viral clearance in the pathogenesis of long COVID syndrome. We focused on potential associations between post-vaccination changes of antibody titers and the severity of long COVID symptoms and factors influencing the state of remission observed in patients with long COVID after vaccination. Methods: The severity of long COVID symptoms and serum anti-SARS-CoV-2 spike (S-Ig) and nucleocapsid (NC-Ig) levels were assessed in 107 post-COVID subjects at two time points: at baseline, and 17–24 weeks later. Besides, vaccination status was also assessed. Symptoms were evaluated based on the Chalder fatigue scale (CFQ-11) and visual analogue scale (VAS). Results: Serum level of S-Ig and NC-Ig at baseline were significantly higher in the patients with non-severe fatigue than those with severe fatigue, and this difference remained significant at follow-up in the case of NC-Ig. NC-Ig level above median was as an independent predictor for complete remission at follow-up. The difference in NC-Ig levels in subgroup analyses (severe fatigue vs. non-severe fatigue; complete remission vs. incomplete remission or progression) was found to be significant only in patients who received vaccination. Conclusions: The immune response against the SARS-CoV-2 nucleocapsid may play a more important role than the spike in the course of long-term COVID syndrome.
Discussion:
[...]
In general, one of the main theories is the insufficient clearance of viral fragments. The patients who have low levels of antibodies at the time of hospital discharge may have a high risk of developing redetectable SARS-CoV-2 RNA on RT-PCR testing after recovery. These findings indicate the important role of these antibodies in viral clearance [10]. SARS-CoV2 nucleocapsid protein has RNA-binding and chaperone activities and promotes SARS-CoV-2 gRNA replication [11]; thus, an inadequate humoral immune response (against nucleocapsid antigen) may indirectly promote further viral replication and lead to further partial persistence of symptoms. [...]
The study: https://www.mdpi.com/2076-393X/10/2/165/htm
Background: Long COVID is a condition characterized by long-term sequelae persisting after the typical convalescence period of COVID-19. Previous reports have suggested the role of an unsatisfactory immune response and impaired viral clearance in the pathogenesis of long COVID syndrome. We focused on potential associations between post-vaccination changes of antibody titers and the severity of long COVID symptoms and factors influencing the state of remission observed in patients with long COVID after vaccination. Methods: The severity of long COVID symptoms and serum anti-SARS-CoV-2 spike (S-Ig) and nucleocapsid (NC-Ig) levels were assessed in 107 post-COVID subjects at two time points: at baseline, and 17–24 weeks later. Besides, vaccination status was also assessed. Symptoms were evaluated based on the Chalder fatigue scale (CFQ-11) and visual analogue scale (VAS). Results: Serum level of S-Ig and NC-Ig at baseline were significantly higher in the patients with non-severe fatigue than those with severe fatigue, and this difference remained significant at follow-up in the case of NC-Ig. NC-Ig level above median was as an independent predictor for complete remission at follow-up. The difference in NC-Ig levels in subgroup analyses (severe fatigue vs. non-severe fatigue; complete remission vs. incomplete remission or progression) was found to be significant only in patients who received vaccination. Conclusions: The immune response against the SARS-CoV-2 nucleocapsid may play a more important role than the spike in the course of long-term COVID syndrome.
Discussion:
[...]
In general, one of the main theories is the insufficient clearance of viral fragments. The patients who have low levels of antibodies at the time of hospital discharge may have a high risk of developing redetectable SARS-CoV-2 RNA on RT-PCR testing after recovery. These findings indicate the important role of these antibodies in viral clearance [10]. SARS-CoV2 nucleocapsid protein has RNA-binding and chaperone activities and promotes SARS-CoV-2 gRNA replication [11]; thus, an inadequate humoral immune response (against nucleocapsid antigen) may indirectly promote further viral replication and lead to further partial persistence of symptoms. [...]
The study: https://www.mdpi.com/2076-393X/10/2/165/htm