A framework for monitoring RSV prevention product effectiveness in the United States.

During 2023, the Centers for Disease Control and Prevention (CDC) recommended the first respiratory syncytial virus (RSV) immunizations intended for widespread use in the United States to prevent severe RSV illness in infants and older adults. CDC, in collaboration with federal, public health, and academic partners, is conducting evaluations of real-world effectiveness of recommended RSV immunization products in the United States. Similar frameworks for evaluation are being applied to RSV vaccines and nirsevimab, a long-acting preventative monoclonal antibody, to estimate product effectiveness.

Risk reduction in SARS-CoV-2 infection and reinfection conferred by humoral antibody levels among essential workers during Omicron predominance.

The extent to which semi-quantitative antibody levels confer protection against SARS-CoV-2 infection in populations with heterogenous immune histories is unclear. Two nested case-control studies were designed within the multisite HEROES/RECOVER prospective cohort of frontline workers to study the relationship between antibody levels and protection against first-time post-vaccination infection and reinfection with SARS-CoV-2 from December 2021 to January 2023. All participants submitted weekly nasal swabs for rRT-PCR testing and blood samples quarterly and following infection or vaccination.

Association of mRNA COVID-19 vaccination and reductions in Post-COVID Conditions following SARS-CoV-2 infection in a US prospective cohort of essential workers.

Background: While there is evidence that COVID-19 vaccination protects against development of post-COVID conditions (PCC) after severe infection data are limited on whether vaccination reduces the risk after cases of less-severe non-hospitalized COVID-19 disease with more recent SARS-CoV-2 variant viruses. This study assessed whether COVID-19 vaccination was protective against subsequent development of PCC in persons with predominantly mild initial infections during both Delta and Omicron variant predominance.

Methods: This study utilized a case-control design, nested within the HEROES-RECOVER cohort.

Effectiveness of Bivalent mRNA Vaccines in Preventing Symptomatic SARS-CoV-2 Infection-Increasing Community Access to Testing Program, United States, January-September 2023.

Background: On September 2, 2022, bivalent COVID-19 mRNA vaccines, were recommended to address reduced effectiveness of COVID-19 monovalent vaccines during SARS-CoV-2 Omicron variant predominance.

Methods: Using national pharmacy-based SARS-CoV-2 testing program data from January 15 to September 11, 2023, this test-negative, case-control design study assessed bivalent COVID-19 vaccine effectiveness (VE) against symptomatic infection.

Results: VE against symptomatic infection of a bivalent dose between 2 weeks and 1 month after bivalent vaccination ranged from 46% (95% CI: 38%-52%) for those aged ≥ 65 years to 61% (95% CI 41%-75%) for those aged 12-17 years.

Influenza Vaccine Effectiveness Against Illness and Asymptomatic Infection in 2022-2023: A Prospective Cohort Study.

Background: Previous estimates of vaccine effectiveness (VE) against asymptomatic influenza virus infection based on seroconversion have varied widely and may be biased. We estimated 2022-2023 influenza VE against illness and asymptomatic infection in a prospective cohort.

Methods: In the HEROES-RECOVER cohort, adults at increased occupational risk of influenza exposure across 7 US sites provided weekly symptom reports and nasal swabs for reverse transcription-polymerase chain reaction (RT-PCR) influenza testing.

Cost-effectiveness of vaccinating adults aged 60 years and older against respiratory syncytial virus.

Respiratory syncytial virus (RSV) causes substantial morbidity and mortality in older adults. In May 2023, two subunit RSV vaccines (Arexvy [GSK] and Abrysvo [Pfizer]) received approval from the U.S.

Evaluating Immunologic and Illness Outcomes of SARS-CoV-2 Infection in Vaccinated and Unvaccinated Children Aged ≥ 5 Years, in a Multisite Longitudinal Cohort.

Unlabelled: Hybrid immunity, as a result of infection and vaccination to SARS-CoV-2, has been well studied in adults but limited evidence is available in children. We evaluated the antibody responses to primary SARS-CoV-2 infection among vaccinated and unvaccinated children aged ≥ 5 years.

Methods: A longitudinal cohort study of children aged ≥ 5 was conducted during August 2021-August 2022, at sites in Arizona, Texas, Utah, and Florida.

Hybrid Immunity and SARS-CoV-2 Antibodies: Results of the HEROES-RECOVER Prospective Cohort Study.

Background: There are limited data on whether hybrid immunity differs by count and order of immunity-conferring events (infection with severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] or vaccination against coronavirus disease 2019 [COVID-19]). From a multi-site cohort of frontline workers, we examined the heterogeneity of the effect of hybrid immunity on SARS-CoV-2 antibody levels.

Methods: Exposures included event count and event order, categorized into 7 permutations.

Longitudinal parental perception of COVID-19 vaccines for children in a multi-site, cohort study.

Objectives: Pediatric COVID-19 vaccine hesitancy and uptake is not well understood. Among parents of a prospective cohort of children aged 6 months-17 years, we assessed COVID-19 vaccine knowledge, attitudes, and practices (KAP), and uptake over 15 months.

Methods: The PROTECT study collected sociodemographic characteristics of children at enrollment and COVID-19 vaccination data and parental KAPs quarterly.

Building the U.S. COVID-19 vaccine effectiveness program: Past successes and future directions.

COVID-19 vaccines were originally authorized in the United States in December 2020 on the basis of safety, immunogenicity, and clinical efficacy data from randomized controlled trials (RCTs). However, real-world vaccine effectiveness (VE) data are necessary to provide information on how the vaccines work in populations not included in the RCTs (e.g.

Serum per- and polyfluoroalkyl substance concentrations and longitudinal change in post-infection and post-vaccination SARS-CoV-2 antibodies.

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous throughout the United States. Previous studies have shown PFAS exposure to be associated with a reduced immune response. However, the relationship between serum PFAS and antibody levels following SARS-CoV-2 infection or COVID-19 vaccination has not been examined.

Use of Respiratory Syncytial Virus Vaccines in Older Adults: Recommendations of the Advisory Committee on Immunization Practices - United States, 2023.

Respiratory syncytial virus (RSV) is a cause of severe respiratory illness in older adults. In May 2023, the Food and Drug Administration approved the first vaccines for prevention of RSV-associated lower respiratory tract disease in adults aged ≥60 years. Since May 2022, the Advisory Committee on Immunization Practices (ACIP) Respiratory Syncytial Virus Vaccines Adult Work Group met at least monthly to review available evidence regarding the safety, immunogenicity, and efficacy of these vaccines among adults aged ≥60 years.

Determinants of B cell responses to drifted epitopes in post-vaccination SARS-CoV-2 infections.

Vaccine-induced immunity may impact subsequent responses to drifted epitopes in SARS-CoV-2 variants, but this has been difficult to quantify due to the challenges in recruiting unvaccinated control groups whose first exposure to SARS-CoV-2 is a primary infection. Through local, statewide, and national SARS-CoV-2 testing programs, we were able to recruit cohorts of individuals who had recovered from either primary or post-vaccination infections by either the Delta or Omicron BA.1 variants.

Humoral Immune Response to Messenger RNA Coronavirus Disease 2019 Vaccination Among Children Aged 5-11 Years in a Multisite Prospective Cohort Study, September 2021-September 2022.

Background: The PROTECT study is a longitudinal cohort study initiated in July 2021 with weekly testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 4 states: Arizona, Florida, exas, and Utah. This study aims to examine vaccine-elicited antibody response against postvaccination SARS-CoV-2 infections.

Methods: Children aged 5-11 years had serum collected 14-59 days after their second dose of monovalent Pfizer-BioNTech coronavirus disease 2019 messenger RNA vaccine.

Use of Respiratory Syncytial Virus Vaccines in Older Adults: Recommendations of the Advisory Committee on Immunization Practices - United States, 2023.

Respiratory syncytial virus (RSV) is a cause of severe respiratory illness in older adults. In May 2023, the Food and Drug Administration approved the first vaccines for prevention of RSV-associated lower respiratory tract disease in adults aged ≥60 years. Since May 2022, the Advisory Committee on Immunization Practices (ACIP) Respiratory Syncytial Virus Vaccines Adult Work Group met at least monthly to review available evidence regarding the safety, immunogenicity, and efficacy of these vaccines among adults aged ≥60 years.

Effectiveness of COVID-19 mRNA Vaccines in Preventing COVID-19-Associated Outpatient Visits and Hospitalizations Among American Indian and Alaska Native Persons, January-November 2021: A Test-Negative Case-Control Analysis Using Surveillance Data.

Background: Despite the disproportionate morbidity and mortality experienced by American Indian and Alaska Native (AI/AN) persons during the coronavirus disease 2019 (COVID-19) pandemic, few studies have reported vaccine effectiveness (VE) estimates among these communities.

Methods: We conducted a test-negative case-control analysis among AI/AN persons aged ≥12 years presenting for care from January 1, 2021, through November 30, 2021, to evaluate the effectiveness of mRNA COVID-19 vaccines against COVID-19-associated outpatient visits and hospitalizations. Cases and controls were patients with ≥1 symptom consistent with COVID-19-like illness; cases were defined as those test-positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and controls were defined as those test-negative for SARS-CoV-2.