Event rates and incidence of post-COVID-19 condition in hospitalised SARS-CoV-2 positive children and young people and controls across different pandemic waves: exposure-stratified prospective cohort study in Moscow (StopCOVID)
Authors: Pazukhina Ekaterina , Rumyantsev Mikhail , Baimukhambetova Dina , Bondarenko Elena , Markina Nadezhda , El-Taravi Yasmin , Petrova Polina , Ezhova Anastasia , Andreeva Margarita , Iakovleva Ekaterina , Bobkova Polina , Pikuza Maria , Trefilova Anastasia , Abdeeva Elina , Galiautdinova Aysylu , Filippova Yulia , Bairashevskaia Anastasiia , Zolotarev Aleksandr , Bulanov Nikolay , DunnGalvin Audrey , Chernyavskaya Anastasia , Kondrikova Elena , Kolotilina Anastasia , Gadetskaya Svetlana , Ivanova Yulia V. , Turina Irina , Eremeeva Alina , Fedorova Ludmila A. , Comberiati Pasquale , Peroni Diego G. , Nekliudov Nikita , Genuneit Jon , Reyes Luis Felipe , Brackel Caroline L. H. , Mazankova Lyudmila , Miroshina Alexandra , Samitova Elmira , Borzakova Svetlana , Carson Gail , Sigfrid Louise , Scott Janet T. , McFarland Sammie , Greenhawt Matthew , Buonsenso Danilo , Semple Malcolm G. , Warner John O. , Olliaro Piero , Osmanov Ismail M. , Korsunskiy Anatoliy A. , Munblit Daniel ,   Sechenov StopCOVID Research Team, Aktulaeva Khazhar , Aldanov Islamudin , Alekseeva Nikol , Assanova Ramina , Avagyan Asmik , Babkova Irina , Baziyants Lusine , Berbenyuk Anna , Bezbabicheva Tatiana , Chayka Julia , Cherdantseva Iuliia , Chervyakova Yana , Chitanava Tamara , Chubukov Alexander , Degtiareva Natalia , Demyanov Gleb , Demyanov Semen , Deunezhewa Salima , Dubinin Aleksandr , Dymchishina Anastasia , Dzhavadov Murad , Edilgireeva Leila , Filippova Veronika , Frumkina Yuliia , Gorina Anastasia , Gorlenko Cyrill , Gripp Marat , Grosheva Mariia , Gudratova Eliza , Iakimenko Elena , Kalinina Margarita , Kharchenko Ekaterina , Kholstinina Anna , Kirillov Bogdan , Kiseljow Herman , Kogut Natalya , Kondrashova Polina , Konova Irina , Korgunova Mariia , Kotelnikova Anastasia , Krupina Alexandra , Kuznetsova Anna , Kuznetsova Anastasia , Kuznetsova Anna S. , Laevskaya Anastasia , Laukhina Veronika , Lavginova Baina , Levina Yulia , Lidjieva Elza , Butorina Anastasia , Lyaginskaya Juliya , Lyubimova Ekaterina , Magomedov Shamil , Mamchich Daria , Minazetdinova Rezeda , Mingazov Artemii , Mursalova Aigun , Nikolaeva Daria , Nikolenko Alexandra , Novikov Viacheslav , Novoselov Georgiy , Ovchinnikova Ulyana , Palchikova Veronika , Papko Kira , Pavlova Mariia , Pecherkina Alexandra , Permyakova Sofya , Porubayeva Erika , Presnyakova Kristina , Privalov Maksim , Prutkogliadova Alesia , Pushkareva Anna , Redya Arina , Romanenko Anastasia , Roshchin Filipp , Salakhova Diana , Sankova Maria , Sarukhanyan Ilona , Savina Viktoriia , Semeniako Ekaterina , Seregina Valeriia , Shapovalova Anna , Sharbetova Khivit , Shishkina Nataliya , Shvedova Anastasia , Stener Valeriia , Ustyan Valeria , Valieva Yana , Varaksina Maria , Varaksina Katerina , Varlamova Ekaterina , Vlasova Natalia , Yegiyan Margarita , Ziskina Nadezhda , Zolochevskaya Daniella , Zuykova Elena 
Published: February 2024

Abstract
Background
Long-term health outcomes in children and young people (CYP) after COVID-19 infection are not well understood and studies with control groups exposed to other infections are lacking. This study aimed to investigate the incidence of post-COVID-19 condition (PCC) and incomplete recovery in CYP after hospital discharge and compare outcomes between different SARS-CoV-2 variants and non-SARS-CoV-2 infections.

Methods
A prospective exposure-stratified cohort study of individuals under 18 years old in Moscow, Russia. Exposed cohorts were paediatric patients admitted with laboratory-confirmed COVID-19 infection between April 2 and December 11, 2020 (Wuhan variant cohort) and between January 12 and February 19, 2022 (Omicron variant cohort). CYP admitted with respiratory and intestinal infections, but negative lateral flow rapid diagnostic test and PCR-test results for SARS-CoV-2, between January 12 and February 19, 2022, served as unexposed reference cohort. Comparison between the ‘exposed cohorts’ and ‘reference cohort’ was conducted using 1:1 matching by age and sex. Follow-up data were collected via telephone interviews with parents, utilising the long COVID paediatric protocol and survey developed by the International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC). The WHO case definition was used to categorise PCC.

Results
Of 2595 CYP with confirmed COVID-19, 1707 (65.7%) participated in follow-up interviews, with 1183/1707 (69%) included in the final ‘matched’ analysis. The median follow-up time post-discharge was 6.7 months. The incidence of PCC was significantly higher in the Wuhan variant cohort (89.7 cases per 1000 person-months, 95% CI 64.3–120.3) compared to post-infection sequalae in the reference cohort (12.2 cases per 1000 person-months, 95% CI 4.9–21.9), whereas the difference with the Omicron variant cohort and reference cohort was not significant. The Wuhan cohort had higher incidence rates of dermatological, fatigue, gastrointestinal, sensory, and sleep manifestations, as well as behavioural and emotional problems than the reference cohort. The only significant difference between Omicron variant cohort and reference cohort was decreased school attendance. When comparing the Wuhan and Omicron variant cohorts, higher incidence of PCC and event rates of fatigue, decreased physical activity, and deterioration of relationships was observed. The rate of incomplete recovery was also significantly higher in the Wuhan variant cohort than in both the reference and the Omicron variant cohorts.

Conclusions
Wuhan variant exhibited a propensity for inducing a broad spectrum of physical symptoms and emotional behavioural changes, suggesting a pronounced impact on long-term health outcomes. Conversely, the Omicron variant resulted in fewer post-infection effects no different from common seasonal viral illnesses. This may mean that the Omicron variant and subsequent variants might not lead to the same level of long-term health consequences as earlier variants.