Weekly COVID-19–associated hospitalization rates among U.S. infants and children aged 0–4 years have declined since the peak of January 8, 2022; however, peak rates during Omicron predominance were approximately five times those of the peak during Delta predominance. Similarly, ICU admission rates during Omicron predominance peaked at approximately 3.5 times the peak rate during Delta predominance. The proportion of hospitalized infants and children with severe illness during all variant periods of predominance, coupled with the potential for longer-term sequelae including multisystem inflammatory syndrome,[6,7] highlight the importance of preventing COVID-19 among infants and children aged 0–4 years. Strategies to prevent COVID-19 among infants and young children are important and include vaccination of currently eligible populations such as pregnant women, family members, and caregivers of infants and young children.
The proportion of patients with codetections of RSV was higher during Delta predominance than Omicron predominance. RSV circulation was low during the first year of the pandemic (pre-Delta predominance). The pattern of RSV codetections during 2021–2022 correlated with trends in RSV circulation observed in other surveillance systems: RSV circulation increased during the summer and fall of 2021 (Delta predominance) and declined during Omicron predominance††††. These limited data suggest that the surge in hospitalizations during Omicron predominance was not driven by coinfections. The highest proportion of hospitalized infants and children requiring ICU admission occurred during Delta predominance, and the lowest occurred during Omicron predominance. Although the proportion of hospitalized infants and children admitted to an ICU was higher during Delta predominance, the rate of pediatric ICU admissions during Omicron predominance was approximately 3.5 times as high as that during Delta predominance, driven by the overall higher disease incidence.
Throughout the pandemic, infants aged <6 months have been hospitalized with laboratory-confirmed COVID-19 at higher rates than have infants and children aged 6 months–4 years. Infants aged <6 months were hospitalized with RSV codetections in higher proportions but required ICU admission and respiratory support in similar proportions to other age groups. Future studies are needed to understand the possible long-term consequences of COVID-19 infection among infants. Although infants aged <6 months are not currently eligible for vaccination, evidence suggests that this age group can receive protection through passive transplacental transfer of maternal antibodies acquired through vaccination. CDC recommends that women who are pregnant, breastfeeding, trying to become pregnant, or might become pregnant get vaccinated and stay up to date with COVID-19 vaccination.
The findings in this report are subject to at least four limitations. First, COVID-19–associated hospitalizations and viral coinfections might have been missed because of testing practice differences and test availability; this analysis could not account for changes in viral testing practices over time. Second, periods of variant predominance are not exclusive to a given variant; other variants might be circulating while one predominates. Third, it was not possible to account for seasonality or changes in public health policies and treatment practices over time; for example, the proportion of ICU admissions might reflect changing hospital capacity during the period of variant predominance rather than disease severity. Finally, the COVID-NET catchment areas include approximately 10% of the U.S. population; thus, these findings might not be nationally generalizable.
Coinciding with Omicron predominance, COVID-19–associated hospitalization rates among infants and children aged 0–4 years reached the current highest level of the pandemic during early January 2022. All persons who are eligible for vaccination, including pregnant women, should receive and stay up to date with COVID-19 vaccination to reduce the risk for severe disease for themselves and others with whom they come into contact, including infants and children aged 0–4 years who are currently not eligible for vaccination.
Joelle Nadle, Monica Napoles, Sherry Quach, Gretchen Rothrock, California Emerging Infections Program, Oakland, California; Nisha Alden, Isaac Armistead, Madelyn Lensing, Sarah McLafferty, Millen Tsegaye, Colorado Department of Public Health and Environment; Ann Basting, Tessa Carter, Maria Correa, Daewi Kim, Amber Maslar, Julie Plano, Kimberly Yousey-Hindes, Connecticut Emerging Infections Program, Yale School of Public Health, New Haven, Connecticut; Marina Bruck, Rayna Ceaser, Taylor Eisenstein, Emily Fawcett, Sabrina Hendrick, Johanna Hernandez, Asmith Joseph, Grayson Kallas, Stephanie Lehman, Jana Manning, Annabel Patterson, Allison Roebling, Suzanne Segler, Chandler Surell, Katelyn Ward, Hope Wilson, School of Medicine, Emory University, Georgia Emerging Infections Program, Georgia Department of Public Health, Veterans Affairs Medical Center, Foundation for Atlanta Veterans Education and Research, Atlanta, Georgia; Chloe Brown, Jim Collins, Justin Henderson, Shannon Johnson, Sierra Peguies-Khan, Alexander Kohrman, Lauren Leegwater, Val Tellez Nunez, Libby Reeg, Michigan Department of Health and Human Services; Alison Babb, Richard Danila, Kristen Ehresmann, Jake Garfin, Jennifer Gilbertson, Grace Hernandez, Melissa McMahon, Kieu My Phi, Jill Reaney, Sara Vetter, Xiong Wang, Minnesota Department of Health; Melissa Judson, Sunshine Martinez, Mark Montoya, Florent Nkouaga, Jasmyn Sanchez, Chad Smelser, Daniel Sosin, New Mexico Department of Health; Kathy M. Angeles, Molly Bleecker, Sarah Shrum Davis, Nancy Eisenberg, Emily B. Hancock, Sarah A. Khanlian, Sarah Lathrop, Wickliffe Omondi, Mayvilynne Poblete, Francesca Pacheco, Dominic Rudin, Yadira Salazar-Sanchez, New Mexico Emerging Infections Program; Jennifer Akpo, Celina Chavez, Murtada Khalifa, Alesia Reed, Yassir Talha, CDC Foundation, Atlanta, Georgia; New Mexico Department of Health; Grant Barney, Kerianne Engesser, Suzanne McGuire, Adam Rowe, New York State Department of Health; Sophrena Bushey, Christina Felsen, Maria Gaitan, Christine Long, Thomas Peer, Kevin Popham, University of Rochester School of Medicine and Dentistry, Rochester, New York; Julie Freshwater, Denise Ingabire-Smith, Ann Salvator, Rebekah Sutter, Ohio Department of Health; Sam Hawkins, Public Health Division, Oregon Health Authority; Kathy Billings, Katie Dyer, Anise Elie, Gail Hughett, Karen Leib, Tiffanie Markus, Terri McMinn, Danielle Ndi, Manideepthi Pemmaraju, Emmanuel Sackey, Vanderbilt University Medical Center, Nashville, Tennessee; Ian Buchta, Amanda Carter, Ryan Chatelain, Melanie Crossland, Andrea George, Andrew Haraghey, Mary Hill, Laine McCullough, Jake Ortega, Tyler Riedesel, Caitlin Shaw, Ashley Swain, Salt Lake County Health Department, Salt Lake City, Utah; Rainy Henry, Sonja Mali Nti-Berko, Robert W. Pinner, Alvin Shultz, CDC; Epidemiology Task Force, CDC COVID-19 Emergency Response Team; Elizabeth Daly, Council of State and Territorial Epidemiologists.
Morbidity and Mortality Weekly Report. 2022;71(11):429-436. © 2022 Centers for Disease Control and Prevention (CDC)