COVID-19 Incidence and Mortality Among Unvaccinated and Vaccinated Persons Aged ≥12 Years by Receipt of Bivalent Booster Doses and Time Since Vaccination - 24 U.S. Jurisdictions, October 3, 2021-December 24, 2022.

On September 1, 2022, CDC recommended an updated (bivalent) COVID-19 vaccine booster to help restore waning protection conferred by previous vaccination and broaden protection against emerging variants for persons aged ≥12 years (subsequently extended to persons aged ≥6 months).* To assess the impact of original (monovalent) COVID-19 vaccines and bivalent boosters, case and mortality rate ratios (RRs) were estimated comparing unvaccinated and vaccinated persons aged ≥12 years by overall receipt of and by time since booster vaccination (monovalent or bivalent) during Delta variant and Omicron sublineage (BA.1, BA.2, early BA.4/BA.5, and late BA.4/BA.5) predominance.† During the late BA.4/BA.5 period, unvaccinated persons had higher COVID-19 mortality and infection rates than persons receiving bivalent doses (mortality RR = 14.1 and infection RR = 2.8) and to a lesser extent persons vaccinated with only monovalent doses (mortality RR = 5.4 and infection RR = 2.5). Among older adults, mortality rates among unvaccinated persons were significantly higher than among those who had received a bivalent booster (65-79 years; RR = 23.7 and ≥80 years; 10.3) or a monovalent booster (65-79 years; 8.3 and ≥80 years; 4.2). In a second analysis stratified by time since booster vaccination, there was a progressive decline from the Delta period (RR = 50.7) to the early BA.4/BA.5 period (7.4) in relative COVID-19 mortality rates among unvaccinated persons compared with persons receiving who had received a monovalent booster within 2 weeks-2 months. During the early BA.4/BA.5 period, declines in relative mortality rates were observed at 6-8 (RR = 4.6), 9-11 (4.5), and ≥12 (2.5) months after receiving a monovalent booster. In contrast, bivalent boosters received during the preceding 2 weeks-2 months improved protection against death (RR = 15.2) during the late BA.4/BA.5 period. In both analyses, when compared with unvaccinated persons, persons who had received bivalent boosters were provided additional protection against death over monovalent doses or monovalent boosters. Restored protection was highest in older adults. All persons should stay up to date with COVID-19 vaccination, including receipt of a bivalent booster by eligible persons, to reduce the risk for severe COVID-19.

Emerging Evidence for Infectious Causes of Cancer in the United States.

Worldwide, infectious agents currently contribute to an estimated 15% of new cancer cases. Most of these (92%, or 2 million new cancer cases) are attributable to 4 infectious agents: Helicobacter pylori, human papillomavirus, and hepatitis B and C viruses. A better understanding of how infectious agents relate to the US cancer burden may assist new diagnostic and treatment efforts. We review US-specific crude mortality rates from infection-associated cancers and describe temporal and spatial trends since 1999. We review the US-specific evidence for infection-cancer associations by reporting available estimates for attributable fractions for the infection-cancer associations. Death due to cancers with established infectious associations varies geographically, but estimates for the US attributable fraction are limited to a few observational studies. To describe the burden of infection-associated cancer in the United States, additional observational studies are necessary to estimate the prevalence of infection nationally and within subpopulations. As infectious associations emerge to explain cancer etiologies, new opportunities and challenges to reducing the burden arise. Improved estimates for the United States would help target interventions to higher-risk subpopulations.

Recent Incarceration Among Individuals Infected With Hepatitis A Virus During Person-to-Person Community Outbreaks, United States, 2016-2020.

OBJECTIVES: Although many people who are incarcerated have risk factors for hepatitis A virus (HAV) infection, the proportion of hepatitis A cases among people with a recent incarceration is unknown. We examined the relationship between recent incarceration and HAV infection during community-based, person-to-person outbreaks to inform public health recommendations. METHODS: The Centers for Disease Control and Prevention surveyed health departments in 33 jurisdictions reporting person-to-person HAV outbreaks during 2016-2020 on the number of outbreak-associated cases, HAV-infected people recently incarcerated, and HAV-associated hospitalizations and deaths. RESULTS: Twenty-five health departments reported 18 327 outbreak-associated hepatitis A cases during January 11, 2016-January 24, 2020. In total, 2093 (11.4%) HAV-infected people had been recently incarcerated. Of those with complete data, 1402 of 1462 (95.9%) had been held in a local jail, and 1513 of 1896 (79.8.%) disclosed hepatitis A risk factors. Eighteen jurisdictions reported incarceration timing relative to the exposure period. Of 9707 cases in these jurisdictions, 991 (10.2%) were among recently incarcerated people; 451 of 688 (65.6%) people with complete data had been incarcerated during all (n = 55) or part (n = 396) of their exposure period. CONCLUSIONS: Correctional facilities are important settings for reaching people with risk factors for HAV infection and can also be venues where transmission occurs. Providing HAV vaccination to incarcerated people, particularly people housed in jails, can be an effective component of community-wide outbreak response.

Covid-19 Rates by Time since Vaccination during Delta Variant Predominance.

BACKGROUND: With the emergence of the delta variant, the United States experienced a rapid increase in Covid-19 cases in 2021. We estimated the risk of breakthrough infection and death by month of vaccination as a proxy for waning immunity during a period of delta variant predominance. METHODS: Covid-19 case and death data from 15 U.S. jurisdictions during January 3 to September 4, 2021 were used to estimate weekly hazard rates among fully vaccinated persons, stratified by age group and vaccine product. Case and death rates during August 1 to September 4, 2021 were presented across four cohorts defined by month of vaccination. Poisson models were used to estimate adjusted rate ratios comparing the earlier cohorts to July rates. RESULTS: During August 1 to September 4, 2021, case rates per 100,000 person-weeks among all vaccine recipients for the January to February, March to April, May to June, and July cohorts were 168.8 (95% confidence interval [CI], 167.5 to 170.1), 123.5 (95% CI, 122.8 to 124.1), 83.6 (95% CI, 82.9 to 84.3), and 63.1 (95% CI, 61.6 to 64.6), respectively. Similar trends were observed by age group for BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccine recipients. Rates for the Ad26.COV2.S (Janssen-Johnson & Johnson) vaccine were higher; however, trends were inconsistent. BNT162b2 vaccine recipients 65 years of age or older had higher death rates among those vaccinated earlier in the year. Protection against death was sustained for the mRNA-1273 vaccine recipients. Across age groups and vaccine types, people who were vaccinated 6 months ago or longer (January-February) were 3.44 (3.36 to 3.53) times more likely to be infected and 1.70 (1.29 to 2.23) times more likely to die from COVID-19 than people vaccinated recently in July 2021. CONCLUSIONS: Our study suggests that protection from SARS-CoV-2 infection among all ages or death among older adults waned with increasing time since vaccination during a period of delta predominance. These results add to the evidence base that supports U.S. booster recommendations, especially for older adults vaccinated with BNT162b2 and recipients of the Ad26.COV2.S vaccine. (Funded by the Centers for Disease Control and Prevention.).

Racial and Ethnic Disparities in Multisystem Inflammatory Syndrome in Children in the United States, March 2020 to February 2021.

BACKGROUND: The incidence of multisystem inflammatory syndrome in children (MIS-C) varies by race and ethnicity. This study assessed whether disparities in MIS-C in the United States by race and ethnicity exceed known disparities in coronavirus disease 2019 (COVID-19) incidence. METHODS: We compared the distribution of race and ethnicity among patients with MIS-C (<21 years of age, termed children) with onset March 2020 to February 2021 to that of children with COVID-19 and in the general population. Analysis was restricted to 369 counties with high completeness of race and ethnicity reporting for MIS-C and COVID-19. For each racial and ethnic group, observed numbers of patients with MIS-C were compared with expected numbers (observed/expected ratio) in children with COVID-19 and in the general population within these counties. RESULTS: Compared with children in the general population, MIS-C was more frequent among Hispanic (139% of expected) and non-Hispanic Black children (183%) and less frequent among non-Hispanic White (64%) and non-Hispanic Asian children (48%). Compared with children with COVID-19, MIS-C was more frequent in non-Hispanic Black children (207% of expected) and less frequent in non-Hispanic White children (68%); however, frequency was not different among Hispanic (102%) and non-Hispanic Asian (74%) children. CONCLUSIONS: Disparities in MIS-C by race and ethnicity exist, even after controlling for COVID-19 disparities and geographic variations. The high proportion of MIS-C among Hispanic children and low proportion among non-Hispanic Asian children align with COVID-19 rates, while the high proportion among non-Hispanic Black children and low proportion among non-Hispanic White children are not explainable by COVID-19 rates.