After the emergence of the Omicron variant, the rate of COVID-19 hospitalizations in the United States was 10.5 times higher in unvaccinated adults and 2.5 times higher in those who were vaccinated but received no booster than in booster recipients, according to a new study. 1). We examined the effectiveness of maternal vaccination against SARS-CoV-2 infection in 30,311 infants born at Kaiser Permanente Northern California from December 15, 2020, to May 31, 2022. The rate among adults who received a primary series, but no booster or additional dose (133.5), was three times the rate among adults who received a booster or additional dose (45.0). The TND, a case-control study, has been commonly used in studies of the effectiveness of influenza vaccines and more recently COVID-19 vaccines. The funders played no direct role in the study. A recent study found that the mean titer of maternally derived antibodies in infants of vaccinated mothers were higher at age 2 months compared with antibody titers at age 6 months23. Further information on research design is available in theNature Portfolio Reporting Summary linked to this article. Cookies used to make website functionality more relevant to you. Atlanta, GA: US Department of Health and Human Services, CDC; 2022. Weekly / March 25, 2022 / 71(12);466473. of pages found at these sites. 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. All HTML versions of MMWR articles are generated from final proofs through an automated process. Vaccine 35, 72977301 (2017). Most QCovid risk groups were tied to an increased risk of post-booster death, except congenital heart disease, asthma, and previous fracture. Zerbo, O. et al. Google Scholar. N. Engl. CAS Blakeway, H. et al. Google Scholar. Adults whose vaccination status had not yet been verified using the immunization information system data were considered to have unknown vaccination status and were included in total proportions but not stratified by vaccination status. 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. During the period of Omicron predominance, hospitalization rates increased most sharply among Black adults in the United States relative to all other racial and ethnic groups examined and reached the highest rate observed among all racial and ethnic groups since the beginning of the pandemic. Klein, N. P. et al. Method: This case-control study aims to determine the hospitalization risk associated with the inactivated BBIBP-CorV (Sinopharm) and mRNA BNT162b2 (Pfizer . Vaccinated patients were older (68 vs. 57 years), and 62% had at least one comorbidity Admission to the ICU was 20%, and the mortality rate at 30 days was 14%. Buchan, S. A. et al. Ousseny Zerbo. The average age of decedents was 83.3 years. 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. Infections are rare and can be severe or fatal, but so far scientists don't see genetic changes that pose an increased threat to people. PubMed Morb. Morb. In the TND, we estimated that during the Delta predominant period, maternal vaccination with at least doses reduced the infants risk of testing SARS-CoV-2 positive by 95% (95% CI:76, 99) during the first 2 months of life, 70% (95% CI: 52, 82) during the first 4 months of life, and 61% (95% CI: 42, 74) during the first 6 months of life (Supplemental Table2). and statistical significance was assessed at two-sided p0.05. Maternal vaccination was protective, but protection was lower during the Omicron period than during Delta. Messer, L. C. et al. Vaccine 31, 21652168 (2013). Defined as one or more of the following: chronic lung disease including asthma, chronic metabolic disease including diabetes mellitus, blood disorder/hemoglobinopathy, cardiovascular disease, neurologic disorder, immunocompromising condition, renal disease, gastrointestinal/liver disease, rheumatologic/autoimmune/inflammatory condition, obesity, feeding tube dependency, and wheelchair dependency. Effectiveness of Covid-19 vaccines in ambulatory and inpatient care settings. Most mothers (66.14%) were between ages 25 and <35 years, and more than a quarter (27.27%) were of Asian race, 5.16% were Black, 24.44% were of Hispanic ethnicity and 37.57% were White. N. Engl. New federal data shows adults who received the updated shots cut their risk of being hospitalized with . All these results were similar to those when no adjustments for covariates are made (Supplemental Table1). Data among adults over 50 showed that a booster shot gave even stronger protection. During the first 6 months of life, 940 (3.10%) infants tested positive for SARS-CoV-2 by polymerase chain reaction (PCR) test and 10 (0.03%) infants were hospitalized with a positive SARS-CoV-2 test. 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). 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. J. Med. 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). Starting the week ending December 4, 2021, Maryland data are not included in weekly rate calculations but are included in previous weeks. volume14, Articlenumber:894 (2023) Hospitalisation associated with SARS-CoV-2 delta variant in Denmark. Kaiser Permanente Northern California, Vaccine Study Center, Oakland, CA, USA, Ousseny Zerbo,G. Thomas Ray,Bruce Fireman,Evan Layefsky,Kristin Goddard,Edwin Lewis,Pat Ross&Nicola P. Klein, Yale University, Institute for Global Health, New Haven, CT, USA, Department of Internal Medicine (Infectious Diseases), Yale School of Medicine, New Haven, CT, USA, Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA, Obstetrics and Gynecology, Kaiser Permanente Northern California Oakland, Oakland, CA, USA, Regional Perinatal Service Center, Kaiser Permanente Northern California, Santa Clara, CA, USA, You can also search for this author in Use of trade names and commercial sources is for identification only and does not imply endorsement by the U.S. Department of SARS-CoV-2 infection can lead to severe illnesses and hospitalizations in children and infants2,3,4,5. ISSN 2041-1723 (online). Cookies used to track the effectiveness of CDC public health campaigns through clickthrough data. https://medrxiv.org/cgi/content/short/2021.08.27.21262356v1. Methods: One hundred and . Relative to the Delta-predominant period, a significantly shorter median length of hospital stay was observed during the Omicron-predominant period and smaller proportions of hospitalizations with intensive care unit admission, receipt of invasive mechanical ventilation, or in-hospital death. JAMA Netw. 41, e81e86 (2022). Delahoy MJ, Whitaker M, OHalloran A, et al. Finally, the COVID-NET catchment areas include approximately 10% of the U.S. population; thus, these findings might not be nationally generalizable. This is consistent with data showing the incidence of positive SARS-CoV-2 test results or death from COVID-19 is higher among unvaccinated adults and adults who have not received a booster than among those who have received a booster or additional dose (5). Ann Intern Med 2021;174:140919. The aim of the secondary design was to compare the results of the cohort with TND. Rep. 71, 429436 (2022). Among fully vaccinated people without a booster, rates were lower at 3,355.5 per 100,000 for COVID-19 cases and 35.4 per 100,000 for hospitalizations. part 46, 21 C.F.R. During the proxy omicron period, we found a vaccine effectiveness of 70% (95% confidence interval . 9-14 As of October 2022, 68% of the US population has completed primary series vaccination. In supplemental analyses by trimester of vaccination, receipt of the second dose during the second and third trimesters reduced the risk of infants testing SARS-CoV-2 positive during the Delta dominant period by 91% (95% CI: 63, 98) and 85% (95% CI: 50, 96), respectively, during the first 2 months of life, by 59% (95% CI: 21, 79) and 67% (95% CI: 37, 83) during the first 4 months of life and by 64% (95% CI:31, 81) and 53% (95% CI: 24, 71) during the first 6 months of life. Effectiveness of BNT162b2 vaccination during pregnancy in preventing hospitalization for SARS-CoV-2 in infants. "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. JAMA Netw. TN, NMF, SFlax, MC, DDA, AMP, and ST conceptualised the work. 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. Durability of anti-spike antibodies in infants after maternal COVID-19 vaccination or natural infection. In this analysis, vaccine effectiveness was evaluated as 1 minus the odds ratio. If material is not included in the articles Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. The proportion of hospitalized Black adults who received a primary COVID-19 vaccination series with or without a booster or additional dose increased from 4.7% and 14.9%, respectively, during the Delta-predominant period to 14.8% and 25.5%, respectively, during the Omicron-predominant period; Hispanic adults experienced smaller increases. "The subpopulations with the highest risk should be considered a priority for COVID-19 therapeutics and further booster doses.". Female sex was a protective factor (HR, 0.52), while residence in a nursing home or low-income area was a risk factor. * Adults who completed a primary vaccination series were defined as those who had received the second dose of a 2-dose primary 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 dose. We conducted a descriptive analysis of the study population and calculated crude rates of SARS-CoV-2 infection and hospitalization by maternal vaccination status. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. Stay up to date with what you want to know. Nat Commun 14, 894 (2023). Statistical codes are not publicly available but are available from the corresponding author. 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. And in a second large study during the Omicron period, older people, men, and residents of nursing homes or in low-income areas were most at risk for post-booster COVID-19 death in England, but the risk was very low. Rates cannot be stratified by pregnancy status because the underlying population of pregnant women in the catchment area is unknown. Morb. J. Obstet. During the study period, home testing became more prevalent. Because the immune status of all patients is not known, an additional dose (recommended for persons with a weakened immune system) cannot be distinguished from a booster dose. Monthly COVID-19 hospitalization rates were 3.5 to 17.7 times higher in unvaccinated patients than in their vaccinated counterparts, regardless of whether they had received a booster. COVID-19 vaccination during pregnancy: coverage and safety. Frequency, characteristics and complications of COVID-19 in hospitalized infants. Our findings that receipt of at least two doses of COVID-19 vaccine during pregnancy was effective at protecting infants during the Delta period are similar to those reported in a recent Norwegian study showing that mRNA COVID-19 vaccination during pregnancy was associated with a 71% decreased risk of testing positive for SARS-CoV-2 in infants during their first 4 months of life during the Delta period17. These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine. 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. ; COVID-NET Surveillance Team. NMF, MC, GD, DDA, AMP, and ST handled project administration. Monthly incidence is based on SARS-CoV-2 positive test result date or, if not known, hospital admission date. Although the study was unable to directly estimate VE against hospitalization due to the small number of hospitalized cases, it found that over the entire study period, the incidence rate of hospitalization during the first 6 months of life was much lower among the infants whose mothers were vaccinated during pregnancy compared with those whose mothers were not vaccinated. The images or other third party material in this article are included in the articles Creative Commons license, unless indicated otherwise in a credit line to the material. 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. mmwrq@cdc.gov. The cohort analyses may be biased toward the null if some infected infants were misclassified as uninfected due to the absence of a SARS-CoV-2 test result in the medical record. NMF, MC, GD, DDA, AMP, and ST supervised the work. These proportions are lower compared with 47.3% of White persons who received a primary series and 54.5% of eligible adults who received a booster dose. Relative to the Delta-predominant period, Black adults accounted for a larger proportion of unvaccinated adults during the Omicron-predominant period, and age-adjusted hospitalization rates for Black adults increased to the highest rate among all racial and ethnic groups for any week during the pandemic. Selected counties in California, Colorado, Connecticut, Georgia, Maryland, Michigan, Minnesota, New Mexico, New York, Ohio, Oregon, Tennessee, and Utah (https://www.cdc.gov/mmwr/volumes/69/wr/mm6915e3.htm). 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. 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). and JavaScript. Table 2. Delta period: July 1, 2021December 18, 2021, reflects the time when Delta was the predominant circulating variant; Omicron period: December 19, 2021January 31, 2022, reflects the time when Omicron was the predominant circulating variant. Individual and neighborhood factors associated with failure to vaccinate against influenza during pregnancy. MMWR Morb Mortal Wkly Rep 2022;71:1328. We conducted secondary sensitivity analyses restricting the population to infants who received at least one SARS-CoV-2 PCR test. 387, 187189 (2022). This case-positive, control-test-negative design also referred to as the test-negative design (TND) has often been used in studies of vaccine effectiveness. Chi-square tests were used to compare differences between the Delta- and Omicron-predominant periods; p-values <0.05 were considered statistically significant. Only 16% of children between the ages of 5 and 11 are fully vaccinated, and that number climbs to just over 50% of adolescents between ages 12 and 17, according to CDC data . According to the Ontario Science Table's online dashboard, the hospital occupancy rate for the unvaccinated was 611 per million unvaccinated people in the province's population as of Jan. 7,. J. Med. COVID-NET conducts population-based surveillance for laboratory-confirmed COVID-19associated hospitalizations in 99 counties across 14 states. COVID-19associated hospitalizations are those occurring among residents of a predefined surveillance catchment area who have a positive real-time reverse transcriptionpolymerase chain reaction (RT-PCR) or rapid antigen detection test result for SARS-CoV-2 during hospitalization or the 14 days preceding admission. If the SARS-CoV-2 test date was not available, hospital admission date was used. Effectiveness of COVID-19 vaccines in preventing hospitalization among adults aged 65 yearsCOVID-NET, 13 states, FebruaryApril 2021. 1.04-1.49) after adjusting for age, sex, and vaccine characteristics. Surveillance officers abstracted data on sampled patients from medical charts. Weekly rates among unvaccinated adults and adults who received a primary COVID-19 vaccination series with a booster or additional dose peaked at 149.8 (January 8, 2022) and 11.7 (January 22, 2022), respectively. Article ** Total hospitalizations include data from selected counties in 14 COVID-NET states irrespective of vaccination status and includes adults with partial or unknown vaccination status. Additional COVID-NET methods for determining vaccination status have been described previously. As of January 26, 2022, 39.6% of Black persons received a primary vaccine series; of those, 43.9% of adults received a booster dose once eligible. 139, e20164091 (2017). Voysey, M., Pollard, A. J., Sadarangani, M. & Fanshawe, T. R. Prevalence and decay of maternal pneumococcal and meningococcal antibodies: a meta-analysis of type-specific decay rates. . The U.K. Health. TN and NMF were responsible for visualisation. COVID-19 vaccine surveillance report: week 6. In January 2022, unvaccinated adults and those vaccinated with a primary series, but no booster or additional dose, were 12 and three times as likely to be hospitalized, respectively, as were adults who received booster or additional doses. Office of the Vice President for Research. MMWR Morb Mortal Wkly Rep 2022;71:14652. In the meantime, to ensure continued support, we are displaying the site without styles Danino, D. et al. Ainslie, K. E. C., Shi, M., Haber, M. & Orenstein, W. A. Persons who received only 1 vaccine dose of a 2-dose series 14 days before the SARS-CoV-2 test date or had received a single dose of either a 1- or 2-dose vaccination series <14 days before the positive SARS-CoV-2 test result were considered partially vaccinated and were not included in rates by vaccination status. Aircraft wastewater surveillance could be used with traveler-based surveillance to provide an early warning system for COVID-19 and other pathogens. After the emergence of the Omicron variant, the rate of COVID-19 hospitalizations in the United States was 10.5 times higher in unvaccinated adults and 2.5 times higher in those who were vaccinated but received no booster than in booster recipients, according to a new study. Dr. Klein reported receiving grants from Pfizer, Merck, GlaxoSmithKline, and Sanofi Pasteur. Analyses were conducted using SAS statistical software survey procedures (version 9.4; SAS Institute). J. Med. JAMA Netw Open 2021;4:e2130479. 40, e137e145 (2021). Nature. A WHO spokesman says China informed the WHO about the case, which involves a 53-year-old woman, on Feb 24. Rep. 70, 895899 (2021). "People who get vaccinated may be more cautious about COVID in general, or perhaps getting vaccinated makes them less cautious, or they may live in states with more/less COVID risk, etc," Jit said. In this large study which included >30,000 infants, we found that receipt of at least two doses of mRNA COVID-19 vaccine during pregnancy was associated with a decreased risk of infants testing SARS-CoV-2 positive during their first 6 months of life. Wkly. 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. During the Delta period, receipt of one dose during the third trimester reduced infants risk of testing positive for SARS-CoV-2 by 74% (95% CI: 19, 92) during the first 6 months of life (Table3). 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. This analysis describes weekly hospitalization rates during Delta- and Omicron-predominant periods. From this cohort, the study excluded the following infants born to (1) mothers who were not between ages 16 and 50 years at pregnancy onset; (2) mothers who did not have a primary KPNC facility assignment; (3) mothers who were not continuous KPNC members from December 15, 2020 until delivery; (4) mothers who had a positive nasal/throat swab for SARS-CoV-2 by polymerase chain reaction (PCR) prior to pregnancy onset; (5) mothers who had a positive SARS-CoV-2 antibody test documented by KPNC prior to the onset of pregnancy; (6) mothers who received one or more doses of COVID-19 vaccine prior to pregnancy onset. 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). 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. It is possible that this practice may have led to some misclassification of the outcome, and we were unable to assess whether this misclassification was differential between vaccinated and unvaccinated mothers. Evan J. Anderson reports grants from Pfizer, Merck, PaxVax, Micron, Sanofi-Pasteur, Janssen, MedImmune, and GlaxoSmithKline; personal fees from Pfizer, Medscape, Kentucky Bioprocessing, Inc., Sanofi-Pasteur, and Janssen, outside the submitted work; and institutional funding from the National Institutes of Health to conduct clinical trials of Moderna and Janssen COVID-19 vaccines. TN, NMF, SB, EV, SRS, DDA, and AMP developed the methodology. pdf files, Omicron: fewer adverse outcomes come with new dangers, Statement on offensive historical content, Redistribute or republish the final article, Reuse portions or extracts from the article in other works. 384, 14121423 (2021). During the Omicron-predominant period, hospitalization rates increased among unvaccinated persons and those who completed a primary series, with and without receipt of a booster or additional dose (Figure 2). Rates were highest among unvaccinated adults and lowest among those who had received a booster or additional dose. 386, 15321546 (2022). During Omicron predominance, shortly after the Food and Drug Administration authorized COVID-19 vaccination for this age group, population-based hospitalization rates among unvaccinated children were twice as high as were those among vaccinated children. KPNC members are similar to the broad catchment population in Northern California in terms of sociodemographic characteristics34.