omicron hospitalization rate vaccinated by age

Wkly. This is in keeping with the age profile. When possible, CDC associates a persons primary vaccination series and booster dose with that person. Hospitalization rates during peak Omicron circulation (January 2022) among unvaccinated adults remained 12 times the rates among vaccinated adults who received booster or additional doses and four times the rates among adults who received a primary series, but no booster or additional dose. Overall, 63% of Americans are fully vaccinated. Blakeway, H. et al. Without the vaccines many more people would likely be in hospital. Health and Human Services. "The association between the QCovid risk groups and the risk of death were stronger in people who had received a booster and were infected by the Omicron variant compared with evidence from the Alpha and Delta period in doubly vaccinated individuals," the authors wrote. During the study period, home testing became more prevalent. CAS Maternal vaccination with at least two doses reduced the infants risk of testing SARS-CoV-2 positive initially by 84% which decreased to 56% by 6 months of life in the Delta dominant period. Morb. Just 28% of children in the age group - around 8 million . You can review and change the way we collect information below. Data among adults over 50 showed that a booster shot gave even stronger protection. The remaining authors declare no competing interests. Risk was especially high for people with severe combined immunodeficiency (HR, 6.2). The study was conducted among a cohort of infants born between December 15, 2020, and May 31, 2022. Med. These findings are consistent with the diminishing of pregnancy-derived antibodies in infants over time22. PubMedGoogle Scholar. It is possible that our exclusion criteria may have resulted in a final sample that may not be reflective of all KPNC infants. The Centers for Disease Control and Prevention (CDC) cannot attest to the accuracy of a non-federal website. Black adults accounted for a higher percentage of hospitalizations during the Omicron-predominant period (26.7%) than during the Delta-predominant period (22.2%, p = 0.05). Use of trade names and commercial sources is for identification only and does not imply endorsement by the U.S. Department of Morb. Although both approaches adjusted for the same confounding factors, the effectiveness estimates from the TND were higher than those from the cohort design, which is consistent with our previous analyses of influenza vaccine effectiveness in which we also observed that the TND tended to result in higher vaccine effectiveness estimates than did our cohort analyses30. endorsement of these organizations or their programs by CDC or the U.S. URL addresses listed in MMWR were current as of Infect. Nature Communications (Nat Commun) Structural changes in the brain may explain the persistent fatigue and neuropsychiatric complications tied to long COVID. Age-adjusted rates were calculated by dividing the number of hospitalized COVID-19 patients by population estimates for race/ethnicity, and vaccination status in the catchment area. This analysis describes weekly hospitalization rates during Delta- and Omicron-predominant periods. COVID-19 vaccination during pregnancy: coverage and safety. Selected counties in California, Colorado, Connecticut, Georgia, Iowa, Maryland, Michigan, Minnesota, New Mexico, New York, Ohio, Oregon, Tennessee, and Utah (https://www.cdc.gov/mmwr/volumes/69/wr/mm6915e3.htm). 20, 15225 (2016). During the Delta period, we found that protection extended through the infants first 6 months of life. Frequency, characteristics and complications of COVID-19 in hospitalized infants. Adults with a positive result whose SARS-CoV-2 test date was 14 days after the first dose of a 2-dose series but <14 days after receipt of the second dose were considered partially vaccinated. Views equals page views plus PDF downloads. Starting the week ending December 4, 2021, Maryland data are not included in weekly rate calculations but are included in previous weeks. Abbreviations: COVID-NET = COVID-19Associated Hospitalization Surveillance Network; ICU=intensive care unit; IMV=invasive mechanical ventilation; LTCF=long-term care facility; NA = not applicable. Female sex was a protective factor (HR, 0.52), while residence in a nursing home or low-income area was a risk factor. and JavaScript. Among these infants, for our main analysis, we excluded 21,891 (35.2%) based on maternal exclusion criteria and 10,412 (16.8%) after applying infant exclusion criteria (Fig. In the present study, the mothers of only 32% of infants in the cohort received at least 2 doses during pregnancy. Risk of hospitalisation associated with infection with SARS-CoV-2 lineage B.1.1.7 in Denmark: an observational cohort study. Percentages presented for demographic characteristics are weighted column percentages. Published by Elsevier Ltd. Secondarily, we used a Test-Negative Design (TND), which is a case-control study, to compare the odds of vaccination among mothers of infants who tested positive vs. the odds of vaccination among mothers of infants who tested negative. This preceded and had no relation to COVID-19, and GD had no role in and received no funding from the project. The study setting was Kaiser Permanente Northern California (KPNC), an integrated healthcare delivery organization that provides comprehensive healthcare to ~4.4 million members as of 2019. All authors reviewed the manuscript. American Academy of Pediatrics. PubMed These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. We thank staff at UKHSA and members of the UK Government SPI-M committee and the UKHSA Variant Technical Group for valuable discussions. N. Engl. Gynecol. *** An additional 172 (3.4%, 95% CI = 2.7%4.2%) adults were partially vaccinated, 69 (0.9%, 95% CI=0.61.2) received a primary vaccination series <14 days before receiving a positive SARS-CoV-2 test result, and 186 (4.1%) had unknown vaccination status; these groups are not further described in this analysis. 2022 The Authors. Durability of anti-spike antibodies in infants after maternal COVID-19 vaccination or natural infection. Department of Health and Human Services. Foppa, I. M., Haber, M., Ferdinands, J. M. & Shay, D. K. The case test-negative design for studies of the effectiveness of influenza vaccine. References to non-CDC sites on the Internet are In the US, as of the end of September 2022, almost 15 million children ages <18 years have tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes Coronavirus Disease 2019 (COVID-19). Age-adjusted hospitalization rates among Black adults peaked at 94.7 (January 8, 2022), higher than that among all other racial and ethnic groups, 3.8 times the rate among White adults (24.8) for the same week, and 2.5 times the previous peak (January 16, 2021) among Black adults (37.2). Overall, the study results support recommendations for vaccination during pregnancy to protect both mothers and their infants. Lipkind, H. S. et al. Schrag, S. J. et al. Image, Download Hi-res Another explanation is the presence of a high COVID-19 vaccination rate among studied individuals (more than two-thirds), which is supported by the finding that the majority of patients had been infected with SARS-CoV-2 prior to undergoing vaccination. In our primary analysis, we implemented a cohort study design where we used Cox proportional hazards models that allow for time-varying covariates to estimate the SARS-CoV-2 infection hazard ratio (HR) in infants of mothers vaccinated with at least 2 doses of mRNA COVID-19 vaccines during pregnancy and 1 dose only versus mothers who were unvaccinated during pregnancy. ***** An additional 172 (3.4%, 95% CI=2.7%4.2%) adults were partially vaccinated, 69 (0.9%, 95% CI=0.61.2) received a primary vaccination series <14 days before a positive for SARS-CoV-2 test result, and 186 (4.1%) had unknown vaccination status; these groups are not further described in this analysis. Although all data used in this analysis were anonymised, the individual-level nature of the data used risks individuals being identified, or being able to self-identify, if the data are released publicly. COVID-19 vaccine surveillance report: week 6. Our analysis . Officials have received a growing number of reports of XDR Shigella, which is highly transmissible and resistant to commonly recommended antibiotics, in adults. Dr. Klein reported receiving grants from Pfizer, Merck, GlaxoSmithKline, and Sanofi Pasteur. However, infants aged <6 months are not currently eligible for any currently available COVID-19 vaccines and must rely on placentally acquired immunity from their mothers. Vaccine effectiveness for 1 dose during the first 6 months of life was 68% (95% CI: 12, 88) (Table2). These persons are excluded from the proportions of race/ethnicity but are included in other analyses. PubMed This is a relevant consideration because vaccines can be less effective in persons with a weakened immune system. By the end of December, Omicron made up 58% of all cases in the US, per Our World in Data, but Delta is thought to cause more severe disease and more hospitalizations than Omicron on average. Includes current treatment or recent diagnosis within the previous 12 months of an immunosuppressive condition or use of an immunosuppressive therapy. Maternal vaccination was protective, but protection was lower during Omicron than during Delta. The group raised concerns about a small number of Guillain-Barre syndrome cases in vaccine recipients and wanted more data, especially on efficacy in those at highest risk. If SARS-CoV-2 test date was missing, hospitalization admission date was used. Characteristics and maternal and birth outcomes of hospitalized pregnant women with laboratory-confirmed COVID-19COVID-NET, 13 states, March 1August 22, 2020. Moline HL, Whitaker M, Deng L, et al. These cookies may also be used for advertising purposes by these third parties. A free-text field for other types of residences was examined; patients with an LTCF-type residence were also categorized as LTCF residents. Children and COVID-19: state data report. Implementing strategies that result in the equitable receipt of COVID-19 vaccinations among persons with disproportionately higher hospitalizations rates, including non-Hispanic Black adults, is an urgent public health priority. Iowa does not provide data on vaccination status. Morb. Receipt of one dose especially during the third trimester was also associated with a reduced risk of infants testing positive for SARS-CoV-2 during the first 6 months of life during the Delta dominant period. 26 Among those fully vaccinated individuals 5 years of age who are booster eligible, only 49% have received a . Omicron Is Not More Severe for Children, Despite Rising Hospitalizations More children are being treated for Covid, but a combination of factors, including low vaccination rates, most. Adults with no documented receipt of any COVID-19 vaccine dose before the test date were considered unvaccinated. The average age of decedents was 83.3 years. In conclusion, in this population-based cohort study, we found that infants born to mothers who received at least two doses of an mRNA COVID-19 vaccine during pregnancy were at lower risk of testing positive for SARS-CoV-2 and were at lower risk of hospitalization during the first 6 months of life compared with infants whose mothers were unvaccinated during pregnancy. It is critical that nursing home residents stay up to date with CO VID-19 vaccines and receive a bivalent booster dose to maximize protection against COVID-19. Vaccine 40, 656665 (2022). Racial and ethnic disparities in rates of COVID-19associated hospitalization, intensive care unit admission, and in-hospital death in the United States from March 2020 to February 2021. CIDRAP - Center for Infectious Disease Research & Policy TN, NMF, SGN, DDA, AMP, and ST wrote the original draft of the manuscript. COVID-19 vaccination coverage among pregnant women during pregnancyEight Integrated Health Care Organizations, United States, December 14, 2020-May 8, 2021. Mortal. Adults with no documented receipt of any COVID-19 vaccine dose before the test date were considered unvaccinated. Third, because immunocompromise status is not always known, it is not possible to distinguish between booster and additional doses; this could have influenced observed rates. Nature. PubMed PubMed Proportions between the pre-Delta and Delta period were compared using chi-square tests; p-values <0.05 were considered statistically significant, adjusted for multiple comparisons using the Bonferroni correction method. Spontaneous abortion following COVID-19 vaccination during pregnancy. supervised chart reviews. 40, e137e145 (2021). Relative to the Delta-predominant period, the proportion of cases in non-Hispanic Asian or Pacific Islanders also increased, whereas the proportion in all other racial and ethnic groups decreased. Maternal vaccination and risk of hospitalization for Covid-19 among infants. The code used to analyse the data is available on. J. Med. Among the infants in the cohort, 19,418 (64.06%) of the mothers were unvaccinated during pregnancy, 1138 (3.75%) of the mothers received one dose of an mRNA COVID-19 vaccine and 9755 (32.18%) received 2 doses during pregnancy (Table1). Annually, approximately 40,000 births occur at KPNC facilities. Cookies used to track the effectiveness of CDC public health campaigns through clickthrough data. Abbreviation: COVID-NET = COVID-19Associated Hospitalization Surveillance Network. COVID-19 incidence and death rates among unvaccinated and fully vaccinated adults with and without booster doses during periods of Delta and Omicron variant emergence25 U.S. Jurisdictions, April 4December 25, 2021. ISSN 2041-1723 (online). But the average . wrote the initial manuscript. Access your favorite topics in a personalized feed while you're on the go. https://www.medrxiv.org/content/10.1101/2022.01.11.22269045v1, https://data.cdc.gov/Vaccinations/COVID-19-Vaccination-Demographics-in-the-United-St/km4m-vcsb. The cumulative monthly age-adjusted hospitalization rate during January 2022 among unvaccinated adults (528.2) was 12 times the rates among those who had received a booster or additional dose (45.0) and four times the rates among adults who received a primary series, but no booster or additional dose (133.5). Baden, L. R. et al. Sign up for notifications from Insider! NHS Test and Trace statistics (England): methodology. Messer, L. C. et al. In the first study, a team led by US Centers for Disease Control and Prevention (CDC) researchers analyzed data on 192,509 hospitalizations from more than 250 hospitals in 13 states participating in the COVID-19Associated Hospitalization Surveillance Network from Jan 1, 2021, to Apr 30, 2022. Hobbs, C. V. et al. Among all adults, relative to the Delta-predominant period, COVID-19related illness was the primary reason for admission for a smaller percentage of hospitalizations (87.5% versus 95.5%, p<0.01), and median length of stay was shorter (4 versus 5 days, p<0.01) during the Omicron-predominant period; during this period, the proportion of patients admitted to an intensive care unit, who received invasive mechanical ventilation, and who died in-hospital decreased significantly (all p<0.01). We, therefore, were unable to assess whether maternal infection provided some protection to their infants. Nat Commun 14, 894 (2023). Open 5, e2233273 (2022). Adults who completed a primary vaccination series were persons who had received the second dose of a 2-dose COVID-19 vaccination series or a single dose of a 1-dose product 14 days before a positive SARS-CoV-2 test associated with their hospitalization but received no booster or additional dose. Beginning the week of December 1925, 2021, the B.1.1.529 (Omicron) variant of SARS-CoV-2 (the virus that causes COVID-19) became the predominant circulating variant in the United States (i.e., accounted for >50% of sequenced isolates). The TND, a case-control study, has been commonly used in studies of the effectiveness of influenza vaccines and more recently COVID-19 vaccines. Most mothers (1032 of 1138) who received only one dose received the vaccine during the third trimester. The study had limitations worth noting. Arthur Reingold, Jeremy Roland, Ashley Coates, California Emerging Infections Program, Oakland, California; Breanna Kawasaki, Rachel Herlihy, Isaac Armistead, Madelyn Lensing, Jordan Surgnier, Sarah McLafferty, Colorado Department of Public Health & Environment; Ann Basting, Tessa Carter, Maria Correa, Daewi Kim, Carol Lyons, Hazhia Sorosindi, Connecticut Emerging Infections Program, Yale School of Public Health, New Haven, Connecticut; Emily Fawcett, Katelyn Ward, Jana Manning, Asmith Joseph, Allison Roebling, Chandler Surell, Stephanie Lehman, Taylor Eisenstein, Suzanne Segler, Grayson Kallas, Marina Bruck, Rayna Ceaser, Annabel Patterson, Sabrina Hendrick, Johanna Hernandez, 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; Jim Collins, Shannon Johnson, Justin Henderson, Sue Kim, Alexander Kohrman, Lauren Leegwater, Val Tellez Nunez, Sierra Peguies-Khan, Michigan Department of Health and Human Services; Kayla Bilski, Kristen Ehresmann, Richard Danila, Jake Garfin, Grace Hernandez, Kieu My Phi, Ruth Lynfield, Sara Vetter, Xiong Wang, Minnesota Department of Health; Daniel M. Sosin, Susan L. Ropp, Sunshine Martinez, Jasmyn Sanchez, Cory Cline, Melissa Judson, Florent Nkouaga, Mark Montoya, New Mexico Department of Health; Sarah Lathrop, Kathy M. Angeles, Yadira Salazar-Sanchez, Sarah A. Khanlian, Nancy Eisenberg, Dominic Rudin, Sarah Shrum Davis, Mayvilynne Poblete, Emily B. Hancock, Francesca Pacheco, New Mexico Emerging Infections Program; Yassir Talha, Celina Chavez, Jennifer Akpo, Alesia Reed, Murtada Khalifa, CDC Foundation, New Mexico Department of Health; Suzanne McGuire, Kerianne Engesser, Nancy Spina, Adam Rowe, New York State Department of Health; Sophrena Bushey, Virginia Cafferky, 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; Tiffanie Markus, Katie Dyer, Karen Leib, Terri McMinn, Danielle Ndi, Gail Hughett, Emmanuel Sackey, Kathy Billings, Anise Elie, Manideepthi Pemmaraju, Vanderbilt University Medical Center, Nashville, Tennessee; Amanda Carter, Andrea George, Andrew Haraghey, Ashley Swain, Caitlin Shaw, Laine McCullough, Mary Hill, Ryan Chatelain, Salt Lake County Health Department, Salt Lake City, Utah; Alvin Shultz, Robert W. Pinner, Rainy Henry, Sonja Mali Nti-Berko, CDC; Elizabeth Daly, Council of State and Territorial Epidemiologists. Urban Health 83, 10411062 (2006). Using Cox regression, the effectiveness of 2 doses of COVID-19 vaccine received during pregnancy was 84% (95% confidence interval [CI]: 66, 93), 62% (CI: 39, 77) and 56% (CI: 34,71) during months 02, 04 and 0- 6 of a childs life, respectively, in the Delta variant period. The difference between the two studies might be due to population characteristics and the timing of follow-up as ours went through May 31, 2022, while the Norwegian study ended in April 2022. Finally, we conducted additional supplemental analyses to estimate VE among children whose mothers received at least one vaccine dose prior to pregnancy onset and at least one dose during pregnancy. Two new observational studies suggest that COVID-19 vaccination lowers long-COVID incidence and severity. Our additional supplemental analysis suggests that pregnant persons who received at least one vaccine dose before pregnancy should complete their vaccination series during pregnancy to provide protection to their children during the first 6 months of life. The data cannot be shared publicly because the data contain potentially identifying or sensitive patient information and is legally restricted by Kaiser Permanente Northern California. Although hospitalization rates increased for all adults, rates were highest among unvaccinated adults and lowest among adults who had received a primary series and a booster or additional dose. Relative to the Delta-predominant period, a larger proportion of hospitalized Black adults were unvaccinated. There was no link between risk of COVID-19 death and race, except for Indian patients, who were at slightly higher risk than their White peers. Late last year, as Omicron was spreading fast in the US, hospitalization rates per 100,000 rose sharply among unvaccinated adults, while rates in those who were fully vaccinated remained low. We excluded these infants because we were primarily interested in estimating the effectiveness of mRNA vaccines received during pregnancy; (7) mothers who received adenovirus vector vaccines or any non-mRNA platform vaccines during pregnancy; (8) mothers who did not receive their mRNA vaccinations in accordance with CDC recommendationse.g., the timing between dose 1 and dose 2 was not within the recommended intervals; and (9) infants who did not become KPNC members within two calendar months of their birth. After adjusting for covariates, vaccination during pregnancy significantly reduced the risk of the infant testing SARS-CoV-2 positive by 84% (95% confidence interval [CI]: 66, 93) during the first 2 months of life, 62% (95% CI: 39, 77) during the first 4 months of life and 56% (95% CI: 34,71) during the first 6 months of life. Mothers were classified as either having had 2 doses or one dose of mRNA COVID-19 vaccines during pregnancy (and completed more than 14 days prior to delivery) or not having had any COVID-19 vaccines prior to delivery. Vaccination status (unvaccinated, receipt of a primary series only, or receipt of a primary series plus a booster or additional dose) was determined for individual hospitalized patients and for the catchment population using state immunization information systems data (2). Chi-square tests were used to compare differences between the Delta- and Omicron-predominant periods; p-values <0.05 were considered statistically significant. All rights Reserved. Adults who received booster doses were classified as those who completed their primary vaccination series and received an additional or booster dose of vaccine on or after August 13, 2021, at any time after the completion of their primary series, and 14 days before a positive test result for SARS-CoV-2, because COVID-19associated hospitalizations are a lagging indicator, and time passed after receipt of a booster dose has been shown to be associated with reduced rates of COVID-19 infection (https://www.nejm.org/doi/full/10.1056/NEJMoa2114255). 387, 227236 (2022). Accessed March 10, 2022. Dis. However, in contrast with the Norwegian study which reported that infants of mothers who were vaccinated had a 33% decreased risk of testing positive during the first 4 months of life during the Omicron period17, our study found a 13% reduced risk that was not statistically significant. Rep. 7, 255263 (2022). Rep. 69, 10811088 (2020). Cookies used to enable you to share pages and content that you find interesting on CDC.gov through third party social networking and other websites. Recently another study reported that the effectiveness of mRNA COVID-19 vaccines against infections and hospitalizations among pregnant people was higher during the Delta period than during the Omicron period21. The aim of the secondary design was to compare the results of the cohort with TND. However, these Omicron impacts have been mostly observed in countries with high vaccination rates in the Region: the comparatively lower rate of hospitalizations and deaths so far is in large part thanks to vaccination, particularly of vulnerable groups. Vaccination status is not available for Iowa and cases from Iowa are excluded from analyses that examined vaccination status. Using previously described methods (3), investigators collected clinical data on a representative sample of adult patients (7.9%) hospitalized during July 1, 2021January 31, 2022, stratified by age and COVID-NET site. You will be subject to the destination website's privacy policy when you follow the link. Most hospitalized children were unvaccinated, and nearly one in three were Black. Maryland did not contribute data after December 4, 2021, but did contribute data for previous weeks. as well as other partner offers and accept our. From Jan 1 to Mar 16, 2022, when Omicron was predominant, 4,781 (0.02%) of 19,473,570 booster recipients died of COVID-19, and 58,020 (0.3%) died of other causes. Effectiveness of Two Doses of BNT162b2 Vaccine before and during Proxy Omicron Period. Libby Reeg reports grants from the Michigan Department of Health and Human Services during the conduct of the study. Infect. * Overall rates are unadjusted; rates presented by racial and ethnic group are age-adjusted. Rates were highest among unvaccinated adults and lowest among those who had received a booster or additional dose. Delahoy MJ, Whitaker M, OHalloran A, et al. A previous study conducted before the Omicron-predominant period that showed increased risk for COVID-19associated hospitalization among certain racial and ethnic groups, including Black adults, and suggested the increased hospitalization rates were likely multifactorial and could include increased prevalence of underlying medical conditions, increased community-level exposure to and incidence of COVID-19, and poor access to health care in these groups (7). https://medrxiv.org/cgi/content/short/2021.08.27.21262356v1. Two to 4 weeks after a booster dose, vaccine effectiveness ranged from around 65-75%, dropped to 55-70% at 5 to 9 weeks, and 40-50% from 10 weeks or more after a booster dose. All information these cookies collect is aggregated and therefore anonymous. The proportion of hospitalized adults who received booster or additional doses increased from 1.3% during the Delta-predominant period to 13.4% during the Omicron-predominant period (p<0.01)***; among these, 10.7% were long-term care facility residents and 69.5% had an immunosuppressive condition. Black adults accounted for 25.2% of all unvaccinated persons hospitalized during the Delta-predominant period; that proportion increased by 23%, to 31.0% during the Omicron-predominant period. Evaluation of acute adverse events after Covid-19 vaccination during pregnancy. The rate among adults who received a primary series, but no booster or additional dose, was three times the rate among adults who received a booster or additional dose. Surveillance officers abstracted data on sampled patients from medical charts. Over the entire study period, the incidence of hospitalization for COVID-19 was lower during the first 6 months of life among infants of vaccinated mothers compared with infants of unvaccinated mothers (21/100,000 person-years vs. 100/100,000 person-years). Two recent papers claim there are no differences between surgical masks and respirators for preventing the spread of respiratory diseases like COVID-19 and flu, but the articles are deeply flawed. 41, e81e86 (2022). Omicron is super infectious, and about 20% of people in the United States over the age of 5 as well as all children under 5 remain unvaccinated. Zerbo, O. et al. The study was funded by the National Institute of Allergy and Infectious Disease grant # 1R01AI168373-01 to O.Z. COVID-19; IL-6 . CDC is not responsible for the content Clinical information was abstracted for 5,681 adults with COVID-19associated hospitalization during July 1, 2021January 31, 2022 (Table). In all models, we used calendar days as the time scale to account for changes over time in SARS-CoV-2 circulation and vaccine uptake. During the Omicron-predominant period, peak hospitalization rates among non-Hispanic Black (Black) adults were nearly four times the rate of non-Hispanic White (White) adults and was the highest rate observed among any racial and ethnic group during the pandemic. But those countries have high vaccination rates, and there, too, Omicron has spread most quickly among younger adults. Open 5, e2232760 (2022). T.R. Author's reply, Efficacy, safety, and immunogenicity of the DNA SARS-CoV-2 vaccine (ZyCoV-D): the interim efficacy results of a phase 3, randomised, double-blind, placebo-controlled study in India, Centers for Disease Control and Prevention, MRC Biostatistics Unit COVID-19 Working Group, Cases, hospital admissions, and hospital attendances in those with delta and omicron SARS-CoV-2 variants, between Nov 29, 2021, and Jan 9, 2022, Risk of hospitalisation and mortality for COVID-19 cases with omicron compared with delta, overall and by age group, Estimated HRs for vaccination categories, secondary analysis. Still, even with a smaller percentage of people getting severely ill during the Omicron wave, a large number of cases over a short time can lead to a spike in people being hospitalized or admitted . Risk factors for severe COVID-19 in children. Data were available for researchers who meet the criteria for access to Kaiser Permanente Northern California confidential data. J. Med. Trends in disease severity and health care utilization during the early Omicron variant period compared with previous SARS-CoV-2 high transmission periodsUnited States, December 2020January 2022. ICU admission status was missing in 1.3% (weighted) of hospitalizations; these hospitalizations are included in other analyses.