Accounting for local incidence when estimating rotavirus vaccine efficacy among countries: a pooled analysis of monovalent rotavirus vaccine trials.

Rotavirus vaccine appears to perform sub-optimally in countries with higher rotavirus burden. We hypothesized that differences in the magnitude of rotavirus exposures may bias vaccine efficacy (VE) estimates, so true differences in country-specific rotavirus VE would be exaggerated without accommodating differences in exposure. We estimated VE against any-severity and severe rotavirus gastroenteritis (RVGE) using Poisson regression models fit to pooled individual-level data from Phase II and III monovalent rotavirus vaccine trials conducted between 2000 and 2012.

Severity-dependent test-seeking behaviors and test-negative designs: impact on estimated vaccine effectiveness and utility of analytic and design choices.

Test-negative designs are increasingly used to evaluate vaccine effectiveness because of desirable properties like reduced confounding due to healthcare-seeking behaviors and lower cost compared to other study designs. An individual's decision to seek care often depends on their disease severity, with severe disease more likely to be captured than mild disease. As many vaccines likely attenuate disease severity, this phenomenon generally results in an upward-biased estimate of vaccine effectiveness against symptomatic disease.

Effectiveness of the fourth dose of COVID-19 vaccines against severe COVID-19 among adults 40 years or older in Brazil: a population-based cohort study.

Background: The emergence of COVID-19 variants with immune scape and the waning of primary vaccine schemes effectiveness have prompted many countries to indicate first and second booster COVID-19 vaccine doses to prevent severe COVID-19. However, current available evidence on second booster dose effectiveness are mostly limited to high-income countries, older adults, and mRNA-based vaccination schemes scenarios. We aimed to investigate the relative vaccine effectiveness (rVE) of the fourth dose compared to three doses for severe COVID-19 outcomes in Brazil; and compare the rVE of a fourth dose with an mRNA vaccine compared to adenovirus-based product in the same settings.

Moral foundations and HPV vaccine acceptance in the United States: State, parental, and individual factors.

Rationale: Appeals to intuitive morality may present a novel approach to addressing vaccine hesitancy.

Objective: To better understand the relationship between morality and vaccination by employing Moral Foundations Theory to studies surrounding the HPV vaccination at multiple different levels of decision making.

Method: We employed three different study modalities which examined moralities link to vaccination by employing Moral Foundations Theory.

Rotavirus Genotypes in the Postvaccine Era: A Systematic Review and Meta-analysis of Global, Regional, and Temporal Trends by Rotavirus Vaccine Introduction.

Background: Even moderate differences in rotavirus vaccine effectiveness against nonvaccine genotypes may exert selective pressures on circulating rotaviruses. Whether this vaccine effect or natural temporal fluctuations underlie observed changes in genotype distributions is unclear.

Methods: We systematically reviewed studies reporting rotavirus genotypes from children <5 years of age globally between 2005 and 2023.

Estimated preventable COVID-19-associated deaths due to non-vaccination in the United States.

While some studies have previously estimated lives saved by COVID-19 vaccination, we estimate how many deaths could have been averted by vaccination in the US but were not because of a failure to vaccinate. We used a simple method based on a nationally representative dataset to estimate the preventable deaths among unvaccinated individuals in the US from May 30, 2021 to September 3, 2022 adjusted for the effects of age and time. We estimated that at least 232,000 deaths could have been prevented among unvaccinated adults during the 15 months had they been vaccinated with at least a primary series.

Risk factors for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) seropositivity among nursing home staff.

Objectives: To estimate prior severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection among skilled nursing facility (SNF) staff in the state of Georgia and to identify risk factors for seropositivity as of fall 2020.

Design: Baseline survey and seroprevalence of the ongoing longitudinal Coronavirus 2019 (COVID-19) Prevention in Nursing Homes study.

Setting: The study included 14 SNFs in the state of Georgia.

Monovalent Rotavirus Vaccine Efficacy Against Different Rotavirus Genotypes: A Pooled Analysis of Phase II and III Trial Data.

Background: Rotavirus vaccine performance appears worse in countries with high rotavirus genotype diversity. Evidence suggests diminished vaccine efficacy (VE) against G2P[4], which is heterotypic with existing monovalent rotavirus vaccine formulations. Most studies assessing genotype-specific VE have been underpowered and inconclusive.

Understanding Variation in Rotavirus Vaccine Effectiveness Estimates in the United States: The Role of Rotavirus Activity and Diagnostic Misclassification.

Background: Estimates of rotavirus vaccine effectiveness (VE) in the United States appear higher in years with more rotavirus activity. We hypothesized rotavirus VE is constant over time but appears to vary as a function of temporal variation in local rotavirus cases and/or misclassified diagnoses.

Methods: We analyzed 6 years of data from eight US surveillance sites on 8- to 59-month olds with acute gastroenteritis symptoms.

Quantifying Risk for SARS-CoV-2 Infection Among Nursing Home Workers for the 2020-2021 Winter Surge of the COVID-19 Pandemic in Georgia, USA.

Objectives: Estimate incidence of and risks for SARS-CoV-2 infection among nursing home staff in the state of Georgia during the 2020-2021 Winter COVID-19 Surge in the United States.

Design: Serial survey and serologic testing at 2 time points with 3-month interval exposure assessment.

Setting And Participants: Fourteen nursing homes in the state of Georgia; 203 contracted or employed staff members from those 14 participating nursing homes who were seronegative at the first time point and provided a serology specimen at second time point, at which time they reported no COVID-19 vaccination or only very recent vaccination (≤4 weeks).

COVID-19 Incidence and Death Rates Among Unvaccinated and Fully Vaccinated Adults with and Without Booster Doses During Periods of Delta and Omicron Variant Emergence - 25 U.S. Jurisdictions, April 4-December 25, 2021.

Previous reports of COVID-19 case, hospitalization, and death rates by vaccination status indicate that vaccine protection against infection, as well as serious COVID-19 illness for some groups, declined with the emergence of the B.1.617.

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.

Do Rotavirus Strains Affect Vaccine Effectiveness? A Systematic Review and Meta-analysis.

Background: Rotavirus causes 215,000 deaths from severe childhood diarrhea annually. Concerns exist that a monovalent vaccine (RV1) and a pentavalent vaccine (RV5) may be less effective against rotavirus strains not contained in the vaccines. We estimated the vaccine effectiveness (VE) of RV1 and RV5 against severe rotavirus gastroenteritis caused by vaccine (homotypic) and nonvaccine (partially and fully heterotypic) strains.

Immunogenicity of influenza vaccines administered to pregnant women in randomized clinical trials in Mali and South Africa.

Background: A key consideration for expanding recommendations for influenza vaccination is a robust assessment of immunogenicity and efficiency of transplacental antibody transfer after maternal vaccination.

Methods: We pooled data from two trials of maternal influenza vaccination to analyze vaccine immunogenicity with more power than either trial had alone. We compared hemagglutination-inhibition (HAI) titers and titer factor change for women and their infants between trial arms using t-tests; maternal and infant putative seroprotective titers (HAI ≥ 1:40) within each trial arm and maternal seroconversion between trial arms using exact tests; and transplacental antibody transfer between trial arms using t-tests.

Vaccine exemption requirements and parental vaccine attitudes: an online experiment.

Increases in vaccine hesitancy and vaccine-preventable disease outbreaks have focused attention on state laws governing school-entry vaccine mandates and the allowable exemptions (medical and nonmedical) from those mandates. There is substantial variation in the type of exemptions available in each state, and states with more rigorous or burdensome exemption requirements generally have lower exemption rates. States have little evidence, however, about how vaccine-hesitant parents respond to different requirements.

Association of cognitive biases with human papillomavirus vaccine hesitancy: a cross-sectional study.

Given the link between vaccine hesitancy and vaccine-preventable disease outbreaks, it is critical to examine the cognitive processes that contribute to the development of vaccine hesitancy, especially among parents of adolescents. We conducted a secondary analysis of baseline data from a two-phase randomized trial on human papillomavirus to investigate how vaccine hesitancy and intent to vaccinate are associated with six decision-making factors: base rate neglect, conjunction fallacy, sunk cost bias, present bias, risk aversion, and information avoidance. We recruited 1,413 adults residing in the United States with at least one daughter aged 9-17 years old through an online survey on Amazon Mechanical Turk.

Cancer-salient messaging for Human Papillomavirus vaccine uptake: A randomized controlled trial.

Background And Objectives: Vaccination with Human Papillomavirus (HPV) vaccine is recommended for 11-12 years-old, but uptake is suboptimal. Current messaging focuses on HPV infection transmission and prevention. Parents and providers are often uncomfortable discussing sexual practices of adolescents, contributing to the delay/refusal of vaccine.

Association of moral values with vaccine hesitancy.

Clusters of unvaccinated children are particularly susceptible to outbreaks of vaccine-preventable disease . Existing messaging interventions demonstrate short-term success, but some may backfire and worsen vaccine hesitancy . Values-based messages appeal to core morality, which influences the attitudes individuals then have on topics like vaccination .

Comparative analysis of the Parent Attitudes about Childhood Vaccines (PACV) short scale and the five categories of vaccine acceptance identified by Gust et al.

Background: There is a need to develop a standardized tool to aid in identifying, measuring and classifying the unique needs of vaccine-hesitant parents (VHPs). This will also assist in designing tailored interventions to address these needs. The Parental Attitude about Childhood Vaccines (PACV) short scale developed by Opel et al.