Revisiting Bacterial Interference in the Age of Methicillin-resistant Staphylococcus aureus: Insights Into Staphylococcus aureus Carriage, Pathogenicity and Potential Control.

Bacteria compete with each other for local supremacy in biologic and environmental niches. In humans, who host an array of commensal bacteria, the presence of one species or strain can sometimes prevent colonization by another, a phenomenon known as "bacterial interference." We describe how, in the 1960s, infants (and later adults) were actively inoculated with a relatively benign strain of Staphylococcus aureus, 502A, to prevent colonization with an epidemic S.

Impact of vaccination on the epidemiology of varicella: 1995-2009.

Background: When varicella vaccine was licensed in the United States in 1995, there were concerns that childhood vaccination might increase the number of adolescents susceptible to varicella and shift disease toward older age groups where it can be more severe.

Methods: We conducted a series of 5 cross-sectional studies in 1994 to 1995 (prevaccine), 2000, 2003, 2006, and 2009 in Kaiser Permanente of Northern California to assess changes in varicella epidemiology in children and adolescents, as well as changes in varicella hospitalization in people of all ages. For each study, information on varicella history and varicella occurrence during the past year was obtained by telephone survey from a sample of ∼8000 members 5 to 19 years old; varicella hospitalization rates were calculated for the entire membership.

Long-term effectiveness of varicella vaccine: a 14-Year, prospective cohort study.

Background: Varicella vaccine was licensed in the United States in 1995 for individuals ≥12 months of age. A second dose was recommended in the United States in June 2006. Varicella incidence and vaccine effectiveness were assessed in a 14-year prospective study conducted at Kaiser Permanente Northern California.

Risk of rheumatoid arthritis following vaccination with tetanus, influenza and hepatitis B vaccines among persons 15-59 years of age.

Background: Associations between vaccinations, particularly hepatitis B, and onset of rheumatoid arthritis (RA) have been reported, but examined in few large-scale studies.

Method: Onset of RA cases and dates of vaccination against hepatitis B, tetanus, and influenza were identified in a retrospective chart review of approximately 1 million Kaiser Permanente Northern California members ages 15-59 years from 1997 through 1999. In a cohort analysis, rates of new-onset RA were compared between vaccinated and unvaccinated within 90, 180, and 365 days.

The blind nasotracheal aspiration method is not a useful tool for pathogen detection of pneumonia in children.

Background: Acute lower respiratory infection (ALRI) is a major cause of hospitalization for children in China, while the etiological diagnosis of ALRI remains a challenge. This study was performed to evaluate the utility of the blind Nasotracheal aspiration (NTA) in the pathogen detection in ALRI through an evaluation of the test's specificity.

Methodology/principal Findings: A hospital-based study of children ≤3 years was carried out from March 2006 through March 2007 in Suzhou University Affiliated Children's Hospital, including 379 cases with ALRI from the respiratory wards, and 394 controls receiving elective surgery.

Overview of the development and current use of CRM(197) conjugate vaccines for pediatric use.

Glycoconjugate vaccines have been proven safe and effective against various diseases in children. Although these vaccines have a history of effectiveness, there are still many unanswered questions to be addressed, including conjugate interference when multiple vaccines are administered at one time, expansion of serotype coverage, effectiveness in special populations, and issues relating to conjugate vaccine use in the developing world. This paper focuses on the use of CRM(197) as a carrier protein, contrasting it to other carrier proteins used in single-antigen pediatric vaccines as well as identifying areas for future study.

Staphylococcal infections: a historical perspective.

Staphylococcus aureus is an unusually successful and adaptive human pathogen that can cause epidemics of invasive disease despite its frequent carriage as a commensal. Over the past 100 years and more, S aureus has caused cycles of outbreaks in hospitals and the community and has developed resistance to every antibiotic used against it, yet the exact mechanisms leading to epidemics of virulent disease are not fully understood. Approaches such as bacterial interference have been effective in interrupting outbreaks, but to better prevent staphylococcal disease, we will need to be vigilant about environmental factors that facilitate its spread.

Varicella immunogenicity with 1- and 2-dose regimens of measles-mumps-rubella-varicella vaccine.

A quadrivalent vaccine combining measles, mumps, rubella, and varicella antigens (MMRV) was developed to increase the coverage of varicella vaccine and reduce the number of injections children receive. Although the varicella antigen is as immunogenic in the latest formulation of MMRV vaccine as when it is administered alone, up to 14% of vaccine recipients do not achieve protective levels of anti-varicella antibodies after a single dose, which can result in breakthrough varicella. A second dose of varicella vaccine raises response rates to 99% and was recently recommended by the Advisory Committee on Immunization Practices.

Lack of association between age at varicella vaccination and risk of breakthrough varicella, within the Northern California Kaiser Permanente Medical Care Program.

Background: Varicella vaccine currently is recommended for children between 12 and 18 months of age. However, rates of breakthrough varicella have been reported to be higher among children vaccinated before 14 or 15 months of age and to increase with time since vaccination.

Methods: An ongoing study at the Northern California Kaiser Permanente Medical Care Program is evaluating vaccine efficacy in 7585 children vaccinated with Varivax in 1995, when they were between 12 and 23 months of age.

Reducing the dose of smallpox vaccine reduces vaccine-associated morbidity without reducing vaccination success rates or immune responses.

Background: When the decision was made to prepare for a deliberate release of smallpox, the United States had approximately 15 million doses of Wyeth Dryvax vaccine, which was known to induce significant morbidity when used undiluted; Sanofi Pasteur, Inc., later identified approximately 85 million additional doses in storage.

Methods: Eleven vaccine-dose groups, each with 30 vaccinia-naive subjects, were given diluted Dryvax vaccine or 1 of 2 lots of Sanofi Pasteur smallpox vaccine and were evaluated for vaccination success rates, morbidity, and immune responses.

Impact of maternal influenza vaccination during pregnancy on the incidence of acute respiratory illness visits among infants.

Objective: To determine whether influenza vaccination of pregnant women prevents visits for respiratory illness in their infants born during the influenza season.

Design: Retrospective matched cohort study.

Setting: Four managed care organizations in the United States.

Safety of trivalent inactivated influenza vaccine in children 6 to 23 months old.

Context: Beginning with the winter season of 2004-2005, influenza vaccination has been recommended for all children 6 to 23 months old in the United States. However, its safety in young children has not been adequately studied in large populations.

Objective: To screen for medically attended events in the clinic, emergency department, or hospital after administration of trivalent inactivated influenza vaccine in children 6 to 23 months old.

Safety and immunogenicity of a combination measles, mumps, rubella and varicella vaccine (ProQuad).

Background: A combination measles, mumps, rubella, and varicella vaccine (ProQuad, Merck & Co., Inc, West Point, PA) was evaluated in five clinical trials. Use of ProQuad would result in fewer injections for children and would facilitate universal immunization against all four diseases.

Effectiveness of heptavalent pneumococcal conjugate vaccine in children younger than 5 years of age for prevention of pneumonia: updated analysis using World Health Organization standardized interpretation of chest radiographs.

Background: A World Health Organization (WHO) working group in 2001 developed a method for standardizing interpretation of chest radiographs in children for epidemiologic purposes. We reevaluated radiographs from the Kaiser Permanente Pneumococcal Efficacy trial using this method.

Methods: Seven-valent pneumococcal conjugate vaccine was evaluated in a randomized, controlled study including 37,868 infants.

Impact of the use of heptavalent pneumococcal conjugate vaccine on disease epidemiology in children and adults.

Pneumococcal conjugate vaccine was introduced for routine use in infants and toddlers in the United States in March 2000. We report on the impact of the introduction of this vaccine on disease epidemiology in young children as well as secondary effects due to herd immunity in unvaccinated children and adults. As of March 2003, 157,471 children had received one or more doses of PNCV7, but only 24% of those less than two years of age received all four doses as a result of shortages of vaccine.

Use of a conjugate polysaccharide vaccine in the prevention of invasive staphylococcal disease: is an additional vaccine needed or possible?

Staphylococcus aureus is a ubiquitous bacterial species that causes serious disease in certain settings. S. aureus disease is difficult to treat, and antibiotic-resistant strains have become common.

The safety and immunogenicity of a quadrivalent measles, mumps, rubella and varicella vaccine in healthy children: a study of manufacturing consistency and persistence of antibody.

Background: This clinical trial was conducted to demonstrate that each of 3 consistency lots of a combined measles, mumps, rubella and varicella vaccine (MMRV) would be well tolerated, induce clinically acceptable and similar immune responses to each antigen and induce immune responses similar to measles, mumps and rubella vaccine (MMR) administered concomitantly with varicella vaccine (V). An additional objective was to evaluate the persistence of antibodies 1 year postvaccination.

Methods: Study participants 12 to 23 months of age received a single injection of either one of 3 consistency lots of MMRV or MMR + V administered at separate injection sites.

Changing epidemiology of outpatient bacteremia in 3- to 36-month-old children after the introduction of the heptavalent-conjugated pneumococcal vaccine.

Background: The introduction of routine vaccination with heptavalent conjugated pneumococcal vaccine has changed the overall incidence of bacteremia in children 3 months-3 years old.

Objective: To describe the changing incidence and etiology of bacteremia in previously healthy toddlers presenting to outpatient clinical settings.

Methods: Retrospective case series of all blood cultures obtained between September 1998 and August 2003 in Kaiser Permanente Northern California outpatient clinics and emergency departments from previously healthy children 3 months-3 years old.

Safety and immunogenicity of a measles, mumps, rubella and varicella vaccine given with combined Haemophilus influenzae type b conjugate/hepatitis B vaccines and combined diphtheria-tetanus-acellular pertussis vaccines.

Background: A study was conducted to assess administration of a combination measles, mumps, rubella and varicella vaccine (MMRV) with other childhood vaccines.

Methods: In this open, multicenter trial, 1915 healthy children ages 12-15 months were randomized into 3 groups: group 1, MMRV, combined Haemophilus influenzae type b conjugate-hepatitis B vaccines (Hib/HepB) and combined diphtheria-tetanus-acellular pertussis vaccines (DTaP) concomitantly; group 2, MMRV followed by Hib/HepB and DTaP 42 days later; group 3, MMR and varicella vaccine followed by Hib/HepB and DTaP 42 days later.

Results: Antibody responses to measles, mumps, rubella, varicella, Hib, HepB, diphtheria and tetanus were similar between groups 1 and 2 (all >95%, except varicella, 89.

Safety and efficacy of a pentavalent human-bovine (WC3) reassortant rotavirus vaccine.

Background: Rotavirus is a leading cause of childhood gastroenteritis and death worldwide.

Methods: We studied healthy infants approximately 6 to 12 weeks old who were randomly assigned to receive three oral doses of live pentavalent human-bovine (WC3 strain) reassortant rotavirus vaccine containing human serotypes G1, G2, G3, G4, and P[8] or placebo at 4-to-10-week intervals in a blinded fashion. Active surveillance was used to identify subjects with serious adverse and other events.

Prevention of Staphylococcus aureus infections: advances in vaccine development.

Staphylococcus aureus is a ubiquitous bacterial species that causes serious disease in a minority of carriers, particularly in hospital settings. S. aureus disease is difficult to treat, and antibiotic-resistant strains have become common.

Active telephone surveillance to evaluate adverse events among civilian smallpox vaccine recipients.

Objective: Better characterize and monitor adverse events following Dryvax vaccinia vaccination in civilian health care workers and other first responders.

Design: Telephone interviews to ascertain adverse events experienced.

Results: Eight hundred twenty-five vaccinees, including 44 in the comparison group, were interviewed.