Some features of the transmission of covid-19 infection in the child population (review)
https://doi.org/10.36604/1998-5029-2022-83-119-131
Abstract
Introduction. During the first wave of the pandemic COVID-19, there was limited and poor quality information on the contribution of children to the transmission of SARS-CoV-2. By early August 2020, several confirmed cases of transmission from children had been published, with no clear evidence that the frequency of transmission from children is higher than that of adults. Since the beginning of the pandemic, children have accounted for 18.4 % of the total number of registered cases, and at the beginning of January 2022, 25.5 % of the total number of COVID-19 cases. Most of the new cases of the disease are Omicron strains. Even with the predicted generally less severe illness resulting from Omicron infection in children, doctors fear that more children may be hospitalized in the coming weeks, given the ever-
increasing number of cases of infection with the virus. Data on the risk of SARS-CoV-2 infection among children compared with adults is needed to inform COVID-19 risks and prevention strategies, including COVID-19 childhood vaccination policy.
Aim. To display literature data containing a review of studies on the transmission of coronavirus infection in children; to analyze the features of the vertical transmission route.
Materials and methods. An analysis was made of publications containing data from studies of cases and features of the transmission of COVID-19 disease in children, including from mother to child.
Results. Currently, foreign sources note several options for the transmission of SARS-CoV-2 in children. SARS-CoV-2 infection during pregnancy may affect pregnancy outcome, delivery, and the birth of a potentially infected baby.
Conclusion. Data on the risk of infection and possible routes of transmission of SARS-CoV-2 in children, including vertical transmission, are needed to improve prevention methods, including immunization of pregnant women and children.
About the Authors
M. A. LazarevaRussian Federation
Maria A. Lazareva, MD, PhD (Med.), Staff Scientist
Khabarovsk Branch – Research Institute of Maternity and Childhood Protection
Group of Clinical Immunology and Endocrinology
680022
49/1 Voronezhskaya Str.
Khabarovsk
G. P. Evseeva
Russian Federation
Galina P. Evseeva, MD, PhD, DSc (Med.), Deputy Director on Scientific Work
Khabarovsk Branch – Research Institute of Maternity and Childhood Protection
680022
49/1 Voronezhskaya Str.
Khabarovsk
S. V. Suprun
Russian Federation
Stefania V. Suprun, MD, PhD, DSc (Med.), Main Staff Scientist
Khabarovsk Branch – Research Institute of Maternity and Childhood Protection
Group of Health and Environmental Problems of Mother and Child Health
680022
49/1 Voronezhskaya Str.
Khabarovsk
O. A. Lebed’ko
Russian Federation
Olga A. Lebed’ko, MD, PhD, DSc (Med.), Director
Khabarovsk Branch – Research Institute of Maternity and Childhood Protection
680022
49/1 Voronezhskaya Str.
Khabarovsk
References
1. South African Institute for Communicable Diseases (NICD) Division of the National Health Laboratory Service. New COVID-19 variant detected in South Africa. New COVID-19 variant detected in South Africa. URL: https://www.nicd.ac.za/new-covid-19-variant-detected-in-south-africa
2. Classification of Omicron (B.1.1.529): SARS-CoV-2 Variant of Concern. Geneva: WHO, 2021. URL: https://www.who.int/news/item/26-11-2021-classification-of-omicron-(b.1.1.529)-sars-cov-2-variant-of-concern
3. Viana R., Moyo S., Amoako D. G., Tegally H., Scheepers C., Althaus C. L., Anyaneji U. J., Bester P. A., Boni M. F., Chand M., Choga W. T., Colquhoun R., Davids M., Deforche K., Doolabh D., du Plessis L., Engelbrecht S., Everatt J., Giandhari J., Giovanetti M. et al. Rapid epidemic expansion of the SARS-CoV-2 Omicron variant in southern Africa // Nature. 2022. https://doi.org/10.1038/s41586-022-04411-y
4. Espenhain L., Funk T., Overvad M., Edslev S. M., Fonager J., Ingham A. C., Rasmussen M., Madsen S. L., Espersen C. H., Sieber R. N., Stegger M., Gunalan V., Wilkowski B., Larsen N. B., Legarth R., Cohen A. S., Nielsen F., Lam J. U. H., Lavik K. E., Karakis M. et al. Epidemiological characterisation of the first 785 SARS-CoV-2 Omicron variant cases in Denmark, December 2021 // Euro Surveill. 2021. Vol. 26, Iss. 50. Article number: 2101146. https://doi.org/10.2807/1560-7917.es.2021.26.50.2101146
5. Burki T. The origin of SARS-CoV-2 variants of concern // Lancet Infect. Dis. 2022. Vol. 22, Iss. 2. P. 174−175. https://doi.org/10.1016/S1473-3099(22)00015-9
6. Madhi S. A., Kwatra G., Myers J. E., Jassat W., Dhar N., Mukendi C. K., Nana A. J., Blumberg L., Welch R., Ngorima-Mabhena N., Mutevedzi P. C. South African Population Immunity and Severe Covid-19 with Omicron Variant // medRxiv. 2021. https://doi.org/10.1101/2021.12.20.21268096
7. Brandal L. T., MacDonald E., Lamprini V., Ravlo T., Lange H., Naseer U., Feruglio S., Bragstad K., Hungnes O., Ødeskaug L. E., Hagen F., Hanch-Hansen K. E., Lind A., Watle S. V., Taxt A. M., Johansen M., Vold L., Aavitsland P., Nygård K., Madslien E. H. Outbreak caused by the SARS-CoV-2 Omicron variant in Norway, November to December 2021 // Euro Surveill. 2021. Vol. 26, Iss. 50. Article number: 16. https://doi.org/10.2807/1560-7917.ES.2021.26.50.2101147
8. Pulliam J. R. C., van Schalkwyk C., Govender N., von Gottberg A., Cohen C., Groome M. J., Dushoff J., Mlisana K., Moultrie H. Increased risk of SARS-CoV-2 reinfection associated with emergence of the Omicron variant in South Africa // medRxiv. 2021. https://doi.org/10.1101/2021.11.11.21266068
9. Kuhlmann C., Mayer C. K., Claassen M., Maponga T., Burgers W. A, Keeton R., Riou C., Sutherland A. D, Suliman T., Shaw M. L., Preiser W. Breakthrough infections with SARS-CoV-2 omicron despite mRNA vaccine booster dose // Lancet. 2022. Vol. 399, Iss. 10325. P. 625–626. https://doi.org/10.1016/S0140-6736(22)00090-3
10. Wu Z., McGoogan J. M. Characteristics of and important lessons from the coronavirus disease 2019 (COVID-19) outbreak in China: summary of a report of 72 314 cases from the Chinese Center for Disease Control and Prevention // JAMA. 2020. Vol. 323, Iss. 13. Р. 1239–1242. https://doi:10.1001/jama.2020.2648
11. Dong Y., Mo X., Hu Y., Qi X., Jiang F., Jiang Z., Tong S. Epidemiological characteristics of 2143 pediatric patients with 2019 coronavirus disease in China // Pediatrics. 2020. Vol. 145, Iss. 6. e20200702. https://doi:10.1542/peds.2020-0702
12. Evseeva G. P., Telepneva R. S., Knizhnikova E. V., Suprun S. V., Pichugina S. V., Yakovlev E. I., Galyant O. I., Kozlov V. K., Lebedko O. A. [COVID-19 in pediatric population]. Bûlleten' fiziologii i patologii dyhaniâ = Bulletin Physiology and Pathology of Respiration 2021; (80):100–114 (in Russian). https://doi.org/10.36604/1998-5029-2021-80-100-114
13. Ministry of Health Singapore. Confirmed cases of local transmission of novel coronavirus infection in Singapore. URL: https://www.moh.gov.sg/news-highlights/details/confirmed-cases-of-local-transmission-of-novel-coronavirus-infection-in-singapore
14. Mehta N. S., Mytton O. T., Mullins E. W. S., Fowler T. A., Falconer C. L., Murphy O. B., Langenberg C., Jayatunga W. J. P., Eddy D. H., Nguyen-Van-Tam J.S. SARS-CoV-2 (COVID-19): what do we know about children? A systematic review // Clin. Infect. Dis. 2020. Vol. 71, Iss. 9. Р. 2469–2479. https://doi.org/10.1093/cid/ciaa556
15. Kam K. Q., Yung C. F., Cui L., Lin Tzer Pin R, Mak T. M., Maiwald M., Li J.,Chong C. Y., Nadua К., Woon Hui Tan N.,Thoon K. C. A Well Infant with Coronavirus Disease 2019 (COVID-19) with High Viral Load // Clin. Infect. Dis. 2020. Vol. 71, Iss. 15. Р. 847–849. https://doi.org/10.1093/cid/ciaa201
16. Lu X, Zhang L, Du H, Zhang J., Li Y. Y., Qu J., Zhang W., Wang Y., Bao S., Li Y., Wu C., Liu H., Liu D., Shao J., Peng X., Yang Y., Liu Z., Xiang Y., Zhang F., SilvaR.M., Pinkerton K. E., Shen К., Xiao Н., Xu S., Wong G. SARS-CoV-2 Infection in Children // N. Engl. J. Med. 2020. Vol. 382. Р. 1663–1665. https://doi.org/10.1056/NEJMc2005073
17. Brodin P. Why is COVID-19 so mild in children? // Acta Paediatr. 2020. Vol. 109, Iss. 6. Р. 1082–1083. https://doi.org/10.1111/apa.15271
18. Huang C., Wang Y., Li X., Ren L., MD J. Z, Hu Y., Zhang L., Fan G., Xu J., Gu X., Cheng Z., Yu T., Xia J., Wei Y., Wu W., Xie X., Yin W., Li H., Liu M., Xiao Y., Gao H., Guo L., Xie J., Wang G., Jiang R., Gao Z., Jin Q., Wang J.,Cao B. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China // Lancet. 2020. Vol. 395, Iss. 10223. P. 497–506. https://doi:10.1016/S0140-6736(20)30183-5.
19. NIH COVID-19 Treatment Guidelines. The COVID-19 Treatment Guidelines Panel's Statement on Therapies for High-Risk, Nonhospitalized Patients With Mild to Moderate COVID-19 (Accessed on January 05, 2022). URL: https://www.covid19treatmentguidelines.nih.gov/therapies/statement-on-therapies-for-high-risk-nonhospitalized-patients/
20. COVID-19 Dashboard by the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University (JHU). URL: https://gisanddata.maps.arcgis.com/apps/opsdashboard/index.html#/bda7594740fd40299423467b48e9ecf6
21. Kwon T., Gaudreault N., Richt J. Seasonal stability of SARS-CoV-2 in biological fluids // bioRxiv. 2021. https://doi.org/10.1101/2021.04.07.438866
22. Costa R., Bueno F, Albert E., Torres I., Carbonell-Sahuquillo S., Barrés-Fernández A., Sánchez D., Padrón C., Colomina J., Carreño M. I. L., Bretón-Martínez J. R., Martínez-Costa C., Navarro D. Upper respiratory tract SARS-CoV-2 RNA loads in symptomatic and asymptomatic children and adults // Clin. Microbiol. Infect. 2021. Vol. 27, Iss. 12. Article number: 1858. https://doi.org/10.1016/j.cmi.2021.08.001
23. Xie W., Chen Z., Wang Q., Song M., Cao Y., Wang L., Pan C. Q. Infection and disease spectrum in individuals with household exposure to SARS‐CoV‐2: A family cluster cohort study // J. Med. Virol. 2021. Vol. 93, Iss. 5. Р. 3033–3046. https://doi.org/10.1002/jmv.26847
24. Bundle N., Dave N., Pharris A., Spiteri G., Deogan C., Suk J. E. COVID-19 trends and severity among symptomatic children aged 0–17 years in 10 European Union countries, 3 August 2020 to 3 October 2021 // Euro Surveill. 2021. Vol. 26. Iss. 50. Article number: 16. https://doi. org/10.2807/1560-7917.ES.2021.26.50.2101098
25. Stein M., Ashkenazi-Hoffnung L., Greenberg D., Dalal I., Livni G., Chapnick G., Stein-Zamir C., Ashkenazi S., Hecht-Sagie L., Grossman Z. The Burden of COVID-19 in Children and Its Prevention by Vaccination: A Joint Statement of the Israeli Pediatric Association and the Israeli Society for Pediatric Infectious Diseases // Vaccines. 2022. Vol. 10, Iss. 1. Article number: 81. https://doi.org/10.3390/vaccines10010081
26. Fang F. C., Benson C. A., Del Rio C., Edwards K. M., Fowler V., Fredricks D., Limaye A., Murray B., Naggie S., Pappas P., Patel R., Paterson D., Pegues D., Petri W., Schooley R. COVID-19-lessons Learned and Questions Remaining // Clin. Infect. Dis. 2021. Vol. 72, Iss. 12. Р. 2225–2240. https://doi.org/10.1093/cid/ciaa1654
27. Clyne B., Jordan K., Ahern S., Walsh K. A., Byrne P., Carty P. G., Drummond L., O'Brien K. K., Smith S. M., Harrington P., Ryan M., O'Neill M. Transmission of SARS-CoV-2 by children: a rapid review, 30 December 2019 to 10 August 2020 // Euro Surveill. 2022. Vol. 27. Iss. 5. Article number: 2001651. https://doi.org/10.2807/1560-7917.ES.2022.27.5.2001651
28. Macartney K., Quinn H. E., Pillsbury A. J., Koirala A., Deng L., Winkler N., Katelaris A. L., O’Sullivan M. V. N., Dalton C., Wood N. Transmission of SARS-CoV-2 in Australian educational settings: a prospective cohort study // Lancet Child Adolesc. Health. 2020. Vol. 4. Iss. 11. Р. 807–816. https://doi.org/10.1016/S2352-4642(20)30251-0
29. European Centre for Disease Prevention and Control (ECDC). COVID-19 in children and the role of school settings in COVID-19 transmission. Stockholm: ECDC; 2020. URL: https://www.ecdc.europa.eu/en/publications-data/children-and-school-settings-covid-19-transmission
30. Stein-Zamir C., Abramson N., Shoob H., Libal E., Bitan M., Cardash T., Cayam R., Miskin I. A large COVID-19 outbreak in a high school 10 days after schools’ reopening, Israel, May 2020 // Euro Surveill. 2020. Vol. 25. Iss. 29. Article number: 2001352. https://doi.org/10.2807/1560-7917.ES.2020.25.29.2001352
31. Meuris C., Kremer C., Geerinck A., Locque M., Bruyère O., Defêche J., Meex C., Hayette M., Duchene L., Dellot P., Azarzar S., Maréchal N., Sauvage A., Frippiat F., Giot J., Léonard P., Fombellida K., Moutschen M., Durkin K., Artesi M., Bours V., Faes C., Hens N., Darcis G. Transmission of SARS-CoV-2 After COVID-19 Screening and Mitigation Measures for Primary School Children Attending School in Liège, Belgium // JAMA Netw. Open. 2021. Vol. 4. Iss. 10. Article number: e2128757. https://doi.org/10.1001/jamanetworkopen.2021.28757
32. Bestle D., Heindl M. R., Limburg H., Lam van T. V., Pilgram O., Moulton H., Stein D. A., Hardes K., Eickmann M., Dolnik O., Rohde C., Becker S., Klenk H., Garten W., Steinmetzer T., Böttcher-Friebertshäuser E. TMPRSS2 and furin are both essential for proteolytic activation and spread of SARS2 CoV-2 in human airway epithelial cells and provide promising drug targets // bioRxiv. 2020. https://doi.org/10.1101/2020.04.15.042085
33. Baranova A. Lenta.ru. Available at: https://lenta.ru/news/2022/02/04/dobicha/ (accessed 04. 02. 2022) (in Russian).
34. Miller F., Nguyen V., Navaratnam A. M., Shrotri M., Kovar J., Hayward A. C., Fragaszy E., Aldridge R. W., Hardelid P. Prevalence of persistent symptoms in children during the COVID-19 pandemic: Evidence from a household cohort study in England and Wales // medRxiv. 2021. https://doi.org/10.1101/2021.05.28.21257602
35. Buonsenso D., Munblit D., De Rose C., Sinatti D., Ricchiuto A., Carfi A., Valentini P. Preliminary Evidence on Long COVID in children // medRxiv. 2021. https://doi.org/10.1101/2021.01.23.21250375
36. Schwartz D. A. An Analysis of 38 Pregnant Women with COVID-19, Their Newborn Infants, and Maternal-Fetal Transmission of SARS-CoV-2: Maternal Coronavirus Infections and Pregnancy Outcomes // Arch. Pathol. Lab. Med. 2020. Vol. 7, Iss. 144. Р. 799–805. https://doi.org/10.5858/arpa.2020-0901-SA
37. Davanzo R, Moro G, Sandri F, Agosti M, Moretti C, Mosca F. Breastfeeding and Coronavirus Disease-2019. Ad interim indications of the Italian Society of Neonatology endorsed by the Union of European Neonatal & Perinatal Societies // Matern. Child Nutr. 2020. Vol. 3, Iss. 16. Article number: e13010. https://doi.org/10.1111/mcn.13010
38. Rasmussen S. A., Smulian J. C., Lednicky J. A., Wen T. S., Jamieson D. J. Coronavirus disease 2019 (COVID‐19) and pregnancy: what obstetricians need to know // Am. J. Obstet. Gynecol. 2020. Vol. 5, Iss. 222. Р. 415–426. https://doi.org/10.1016/j.ajog.2020.02.017
39. Mullins E., Evans D., Viner R., O'Brien P., Morris E. Coronavirus in pregnancy and delivery: rapid review // Ultrasound Obstet. Gynecol. 2020. Vol. 55, Iss. 5. P. 586–592. https://doi.org/10.1002/uog.22014
40. The Royal College of Obstetricians & Gynaecologists. Coronavirus (COVID-19) infection and pregnancy. 2022. URL: https://www.rcog.org.uk/en/guidelines-research-services/guidelines/coronavirus-pregnancy/covid-19-virus-infection-and-pregnancy/
41. Qiao J. What are the risks of COVID-19 infection in pregnant women? // Lancet. 2020. Vol. 395, Iss. 10226. Р. 760–762. https://doi.org/10.1016/S0140-6736(20)30365-2
42. Schwartz D. A. COVID-19, SARS-CoV-2 and Pregnancy: Does the Past Predict the Present? // Contagion Live. 2020. URL: https://www.contagionlive.com/news/covid19-sarscov2-and-pregnancy-does-the-past-predict-the-present
43. [Organization of medical care for pregnant women, parturient women, puerperal and newborns with a new coronavirus infection COVID-19. Version 5]. Methodological recommendations (approved by the Ministry of Health of Russia on December 28, 2021). Available at: https://static.consultant.ru /obj/file/doc/minzdrav_291221-5.pdf (in Russian).
44. Dong L., Tian J., He S., Zhu C., Wang J., Liu C., Yang J. Possible Vertical Transmission of SARS-CoV-2 From an Infected Mother to Her Newborn // JAMA. 2020. Vol. 18, Iss. 323. Р. 1846–1848. https://doi.org/10.1001/jama.2020.4621
45. Chen H., Guo J., Wang C., Luo F., Yu X., Zhang W., Li J., Zhao D., Xu D., Gong Q., Liao J., Yang H., Hou W., Zhang Y. Clinical characteristics and intrauterine vertical transmission potential of COVID‐19 infection in nine pregnant women: a retrospective review of medical records // Lancet. 2020. Vol. 10226, Iss. 395. Р. 809–815. https://doi.org/10.1016/S0140-6736(20)30360-3
46. Zeng L. K., Xia S., Yuan W., Yan K., Xiao F., Shao J., Zhou W. Neonatal early‐onset infections with SARS‐CoV‐2 in 33 neonates born to mothers with COVID‐19 in Wuhan, China // JAMA Pediatr. 2020. Vol. 7, Iss. 174. Р. 722–725. https://doi.org/10.1001/jamapediatrics.2020.0878
47. Hospital Sant Joan de Déu Barcelona. Coronavirus y embarazo, información para pacientes durante la gestación, el parto y el posparto [Coronavirus and pregnancy, information for women during gestation, childbirth and the postpartum period]. Available at: https://www.sjdhospitalbarcelona.org/es/coronavirus-embarazo-informacion-fiable-para-pacientes-durante-gestacion-parto-posparto
48. Govind A., Essien S., Karthikeyan A., Fakokunde A., Janga D., Yoong W., Nakhosteen A. Re: Novel Coronavirus COVID-19 in late pregnancy: Outcomes of first nine cases in an inner city London hospital // Obstet. Gynecol. Reprod. Biol. 2020. Vol. 251. Р. 272–274. https://doi.org/10.1016/j.ejogrb.2020.05.004
49. Suhren J. T, Meinardus A., Hussein K., Schaumann N. Meta-analysis on COVID-19-pregnancy-related placental pathologies shows no specific pattern // Placenta. 2022. Vol. 117. Р. 72–77. https://doi.org/10.1016/j.placenta.2021.10.010
50. Juan J., Gil M. M., Rong Z., Zhang Y., Yang H., Poon L. C. Effect of coronavirus disease 2019 (COVID-19) on maternal, perinatal and neonatal outcome: systematic review // Ultrasound Obstet. Gynecol. 2020. Vol. 1, Iss. 56. Р. 15-27. https://doi.org/10.1002/uog.22088
51. Diriba K., Awulachew E., Getu E.The effect of coronavirus infection (SARS-CoV-2, MERS-CoV, and SARS-CoV) during pregnancy and the possibility of vertical maternal-fetal transmission: a systematic review and meta-analysis // Eur. J. Med. Res. 2020. Vol. 1, Iss. 25. Article number: 39. https://doi.org/10.1186/s40001-020-00439-w
52. Kharbanda E. O., Haapala J., DeSilva M. Vazquez-Benitez G., Vesco K., Naleway A. L., Lipkind H. S. Spontaneous Abortion Following COVID-19 Vaccination During Pregnancy. JAMA. 2021. Vol. 326, Iss. 16. Р. 1629–1631. https://doi.org/10.1001/jama.2021.15494
53. Zauche L. H, Wallace B., Smoots A. N., Olson C., Oduyebo T., Shin Y. Kim, Petersen E. E, Ju J., Beauregard J., Wilcox A., Rose C., Meaney-Delman D., Ellington S. Receipt of mRNA Covid-19 Vaccines and Risk of Spontaneous Abortion // N. Engl. J. Med. 2021. Vol. 385, Iss. 16. Р. 1533–1535. https://doi.org/10.1056/NEJMc2113891
54. Beharier O., Plitman Mayo R., Raz T., Sacks K. N., Schreiber L., Suissa-Cohen Y., Chen R., Gomez-Tolub R., Hadar E., Gabbay-Benziv R., Moshkovich Y. J., Biron-Shental T., Shechter-Maor G., Farladansky-Gershnabel S., Yitzhak Sela H., Benyamini-Raischer H., Sela N., Goldman-Wohl D., Shulman Z., Many A., Barr H., Yagel S., Neeman M., Kovo M.. Efficient maternal to neonatal transfer of antibodies against SARS-CoV-2 and BNT162b2 mRNA COVID-19 vaccine // J. Clin. Invest. 2021. Vol. 131, Iss.13. Article number: e150319. https://doi.org/10.1172/JCI150319
55. Bhattacharyya R. P., Hanage W. P. Challenges in Inferring Intrinsic Severity of the SARS-CoV-2 Omicron Variant // N. Engl. J. Med. 2022. Vol. 386, Iss. 7. Article number: e14. https://doi.org/10.1056/NEJMp2119682
56. Stein M., Ashkenazi-Hoffnung L., Greenberg D., Dalal I., Livni G., Chapnick G., Stein-Zamir C., Ashkenazi S., Hecht-Sagie L., Grossman Z. The Burden of COVID-19 in Children and Its Prevention by Vaccination: A Joint Statement of the Israeli Pediatric Association and the Israeli Society for Pediatric Infectious Diseases // Vaccines. 2022. Vol. 10, Iss. 1. Article number: 81. https://doi.org/10.3390/vaccines10010081
57. Kang M., Xin H., Yuan J., Ali S. T., Liang Z., Zhang J., Hu T., Eric H. Lau Y., Zhang Y., Zhang M., Cowling B. J., Li Y., Wu P. Transmission dynamics and epidemiological characteristics of Delta variant infections in China // medRxiv. 2021. https://doi.org/10.1101/2021.08.12.21261991
58. Richterman A, Meyerowitz E. A., Cevik M. Indirect protection by reducing transmission: ending the pandemic with SARS-CoV-2 vaccination // Open Forum Infect. Dis. 2022 Vol. 9, Iss. 2. Article number: ofab259. https://doi.org/10.1093/ofid/ofab259
59. Fowlkes A., Gaglani M., Groover K., Thiese M., Tyner H., Ellingson K., Cohorts H. Effectiveness of COVID-19 vaccines in preventing SARS-CoV-2 infection among frontline workers before and during B.1.617.2 (Delta) variant predominance – eight U. S. locations, December 2020–August 2021 // MMWR Morb. Mortal. Wkly Rep. 2021. Vol. 70, Iss. 34. Р. 1167–1169. http://dx.doi.org/10.15585/mmwr.mm7034e4
60. Kumar V. J., Sowpati D. T., Munigela A., Banu S., Siva A. B., Sasikala M., Nutalapati C., Kulkarni A., Mukherjee P., Zaveri L. Clinical outcomes in vaccinated individuals hospitalized with Delta variant of SARS-CoV-2 // medRxiv. 2021. https://doi.org/10.1101/2021.07.13.21260417
61. AAP. Analysis of data series titled “COVID-19 Vaccinations in the United States, Jurisdiction” as of February 2, 2022. URL: https://www.aap.org
Review
For citations:
Lazareva M.A., Evseeva G.P., Suprun S.V., Lebed’ko O.A. Some features of the transmission of covid-19 infection in the child population (review). Bulletin Physiology and Pathology of Respiration. 2022;(83):119-131. (In Russ.) https://doi.org/10.36604/1998-5029-2022-83-119-131