Evaluation of vaccine-induced antibody responses: impact of new technologies.

Host response to vaccination has historically been evaluated based on a change in antibody titer that compares the post-vaccination titer to the pre-vaccination titer. A four-fold or greater increase in antigen-specific antibody has been interpreted to indicate an increase in antibody production in response to vaccination. New technologies, such as the bead-based assays, provide investigators and clinicians with precise antibody levels (reported as concentration per mL) in ranges below and above those previously available through standard assays such as ELISA.

Genomic correlates of variability in immune response to an oral cholera vaccine.

Cholera is endemic to many countries. Recent major outbreaks of cholera have prompted World Health Organization to recommend oral cholera vaccination as a public-health strategy. Variation in percentage of seroconversion upon cholera vaccination has been recorded across populations.

Synthesized Population Databases: A Geospatial Database of US Poultry Farms.

The pervasive and potentially severe economic, social, and public health consequences of infectious disease in farmed animals require that plans be in place for a rapid response. Increasingly, agent-based models are being used to analyze the spread of animal-borne infectious disease outbreaks and derive policy alternatives to control future outbreaks. Although the locations, types, and sizes of animal farms are essential model inputs, no public domain nationwide geospatial database of actual farm locations and characteristics currently exists in the United States.

Including the Group Quarters Population in the US Synthesized Population Database.

In 2005, RTI International researchers developed methods to generate synthesized population data on US households for the US Synthesized Population Database. These data are used in agent-based modeling, which simulates large-scale social networks to test how changes in the behaviors of individuals affect the overall network. Group quarters are residences where individuals live in close proximity and interact frequently.

The role of subway travel in an influenza epidemic: a New York City simulation.

The interactions of people using public transportation in large metropolitan areas may help spread an influenza epidemic. An agent-based model computer simulation of New York City's (NYC's) five boroughs was developed that incorporated subway ridership into a Susceptible-Exposed-Infected-Recovered disease model framework. The model contains a total of 7,847,465 virtual people.

Sharing Research Models: Using Software Engineering Practices for Facilitation.

Increasingly, researchers are turning to computational models to understand the interplay of important variables on systems' behaviors. Although researchers may develop models that meet the needs of their investigation, application limitations-such as nonintuitive user interface features and data input specifications-may limit the sharing of these tools with other research groups. By removing these barriers, other research groups that perform related work can leverage these work products to expedite their own investigations.

Social network analysis of patient sharing among hospitals in Orange County, California.

Objectives: We applied social network analyses to determine how hospitals within Orange County, California, are interconnected by patient sharing, a system which may have numerous public health implications.

Methods: Our analyses considered 2 general patient-sharing networks: uninterrupted patient sharing (UPS; i.e.

Genetic determinants of immune-response to a polysaccharide vaccine for typhoid.

Unlabelled: Differences in immunological response among vaccine recipients are determined both by their genetic differences and environmental factors. Knowledge of genetic determinants of immunological response to a vaccine can be used to design a vaccine that circumvents immunogenetic restrictions. The currently available vaccine for typhoid is a pure polysaccharide vaccine, immune response to which is T-cell independent.

Prevalence of high-risk indications for influenza vaccine varies by age, race, and income.

Estimates of the proportions of the population who are at high risk of influenza complications because of prior health status or who are likely to have decreased vaccination response because of immunocompromising conditions would enhance public health planning and model-based projections. We estimate these proportions and how they vary by population subgroups using national data systems for 2006-2008. The proportion of individuals at increased risk of influenza complications because of health conditions varied 10-fold by age (4.

Synthesized Population Databases: A US Geospatial Database for Agent-Based Models.

Agent-based models simulate large-scale social systems. They assign behaviors and activities to "agents" (individuals) within the population being modeled and then allow the agents to interact with the environment and each other in complex simulations. Agent-based models are frequently used to simulate infectious disease outbreaks, among other uses.

Protecting health care workers: a pandemic simulation based on Allegheny County.

Background And Objectives: The Advisory Committee on Immunization Practices has identified health care workers (HCWs) as a priority group to receive influenza vaccine. Although the importance of HCW to the health care system is well understood, the potential role of HCW in transmission during an epidemic has not been clearly established.

Methods: Using a standard SIR (Susceptible-Infected-Recovered) framework similar to previously developed pandemic models, we developed an agent-based model (ABM) of Allegheny County, PA, that incorporates the key health care system features to simulate the spread of an influenza epidemic and its effect on hospital-based HCWs.

Development of a bead immunoassay to measure Vi polysaccharide-specific serum IgG after vaccination with the Salmonella enterica serovar Typhi Vi polysaccharide.

Vi polysaccharide from Salmonella enterica serotype Typhi is used as one of the available vaccines to prevent typhoid fever. Measurement of Vi-specific serum antibodies after vaccination with Vi polysaccharide by enzyme-linked immunosorbent assay (ELISA) may be complicated due to poor binding of the Vi polysaccharide to ELISA plates resulting in poor reproducibility of measured antibody responses. We chemically conjugated Vi polysaccharide to fluorescent beads and performed studies to determine if a bead-based immunoassay provided a reproducible method to measure vaccine-induced anti-Vi serum IgG antibodies.

Signatures of natural selection are not uniform across genes of innate immune system, but purifying selection is the dominant signature.

We tested the opposing views concerning evolution of genes of the innate immune system that (i) being evolutionary ancient, the system may have been highly optimized by natural selection and therefore should be under purifying selection, and (ii) the system may be plastic and continuing to evolve under balancing selection. We have resequenced 12 important innate-immunity genes (CAMP, DEFA4, DEFA5, DEFA6, DEFB1, MBL2, and TLRs 1, 2, 4, 5, 6, and 9) in healthy volunteers (n = 171) recruited from a region of India with high microbial load. We have compared these data with those of European-Americans (EUR) and African-Americans (AFR).

Comprehensive defensin assay for saliva.

Defensins are highly basic cationic peptides that are important components of the innate and adaptive immune response pathways. In addition, these peptides are involved in CD8+ T cell response to HIV-1, increased pulmonary infection risk among cystic fibrosis patients, upregulated levels of HNP-5 for patients with ulcerative colitis and Crohn's disease, and monitoring HNP-3 levels as a tumor classification scheme for cutaneous T cell lymphomas, and have promise in the pharmaceutical field as a new class of antibiotics. Here we present a parallel assay for the alpha (HNP1-3) and beta (HBD1-2) classes of defensins in saliva that are naturally observed in the concentration range of 1 ng/mL to 10 microg/mL.

Family-based detection for hereditary hemochromatosis.

The purpose of this study was to examine motivators for and barriers to family-based detection for hereditary hemochromatosis (HH). HH patients (n = 60) and HH siblings (n = 25) participated in one-on-one or group interviews. Patients and siblings understood that HH "runs in families," but not that siblings are at higher HH risk than other family members.

Controlling pandemic flu: the value of international air travel restrictions.

Background: Planning for a possible influenza pandemic is an extremely high priority, as social and economic effects of an unmitigated pandemic would be devastating. Mathematical models can be used to explore different scenarios and provide insight into potential costs, benefits, and effectiveness of prevention and control strategies under consideration.

Methods And Findings: A stochastic, equation-based epidemic model is used to study global transmission of pandemic flu, including the effects of travel restrictions and vaccination.

State plans for containment of pandemic influenza.

This review assesses differences and similarities of the states in planning for pandemic influenza. We reviewed the recently posted plans of 49 states for vaccination, early epidemic surveillance and detection, and intraepidemic plans for containment of pandemic influenza. All states generally follow vaccination priorities set by the Advisory Committee on Immunization Practices.

Human participants challenges in youth-focused research: perspectives and practices of IRB administrators.

The purpose of this research was to understand institutional review board (IRB) challenges regarding youth-focused research submissions and to present advice from administrators. Semistructured self-report questionnaires were sent via e-mail to administrators identified using published lists of universities and hospitals an Internet searches. Of 183 eligible institutions, 49 responded.

Achieving national health objectives: the impact on life expectancy and on healthy life expectancy.

Our study quantifies the impact of achieving specific Healthy People 2010 targets and of eliminating racial/ethnic health disparities on summary measures of health. We used life table methods to calculate gains in life expectancy and healthy life expectancy that would result from achievement of Healthy People 2010 objectives or of current mortality rates in the Asian/Pacific Islander (API) population. Attainment of Healthy People 2010 mortality targets would increase life expectancy by 2.

Trends in racial and ethnic-specific rates for the health status indicators: United States, 1990-98.

The Health Status Indicators (HSIs) were developed as part of the Healthy People 2000 process to facilitate the comparison of health status measures at national, State,and local levels. In this report national trends in racial and ethnic-specific rates for 17 HSIs are examined for the period from 1990-8. One of three overarching goals of Healthy People 2000 was to reduce health disparities.