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BACKGROUND: Nontypeable Haemophilus influenzae (NTHi) is the most common cause of invasive H. influenzae disease in the United States (US). We evaluated the epidemiology of invasive NTHi disease in the US, including among pregnant women, infants, and people with human immunodeficiency virus (PWH). METHODS: We used data from population- and laboratory-based surveillance for invasive H. influenzae disease conducted in 10 sites to estimate national incidence of NTHi, and to describe epidemiology in women of childbearing age, infants aged ≤30 days (neonates), and PWH living in the surveillance catchment areas. H. influenzae isolates were sent to the Centers for Disease Control and Prevention for species confirmation, serotyping, and whole genome sequencing of select isolates. RESULTS: During 2008-⁠2019, average annual NTHi incidence in the US was 1.3/100 000 population overall, 5.8/100 000 among children aged

Haemophilus influenzae (Hi) can cause meningitis and other serious invasive disease. Encapsulated Hi is classified into six serotypes (a-f) based on chemical composition of the polysaccharide capsule; unencapsulated strains are termed nontypeable Hi (NTHi). Hi serotype b (Hib) was the most common cause of bacterial meningitis in children in the pre-Hib vaccine era, and secondary transmission of Hi among children (e.g., to household contacts and in child care facilities) (1,2) led to the Advisory Committee on Immunization Practices (ACIP) recommendation for antibiotic chemoprophylaxis to prevent Hib disease in certain circumstances.* High Hib vaccination coverage since the 1990s has substantially reduced Hib disease, and other serotypes now account for most Hi-associated invasive disease in the United States (3). Nevertheless, CDC does not currently recommend chemoprophylaxis for contacts of persons with invasive disease caused by serotypes other than Hib and by NTHi (non-b Hi). Given this changing epidemiology, U.S. surveillance data were reviewed to investigate secondary cases of invasive disease caused by Hi. The estimated prevalence of secondary transmission was 0.32% among persons with encapsulated Hi disease (≤60 days of one another) and 0.12% among persons with NTHi disease (≤14 days of one another). Isolates from all Hi case pairs were genetically closely related, and all patients with potential secondary infection had underlying medical conditions. These results strongly suggest that secondary transmission of non-b Hi occurs. Expansion of Hi chemoprophylaxis recommendations might be warranted to control invasive Hi disease in certain populations in the United States, but further analysis is needed to evaluate the potential benefits against the risks, such as increased antibiotic use.

Objective: Quadrivalent meningococcal conjugate vaccines (MenACWY) have been recommended routinely for adolescents since 2005; in 2015, serogroup B meningococcal (MenB) vaccines were recommended for persons aged 16-23 years based on individual clinical decision making. We surveyed college health providers or administrators to understand current meningococcal vaccine policies. Methods/Participants: In January 2017, we distributed a survey to 985 institutions in partnership with the American College Health Association to assess vaccination policies and outbreak response plans. Results: Overall, 352 (36%) institutions completed the survey. Most either required (N = 186, 53%) or recommended (N = 148, 42%) a meningococcal vaccine; only half (N = 167) had a policy specifically addressing MenB vaccines. Few institutions with a MenB vaccine policy required vaccination (N = 7, 4%); most recommended vaccination (N = 160, 96%). Conclusion: Most institutions have a meningococcal vaccination policy; however, there is substantial diversity in policies. Fewer schools have policies specifically addressing MenB vaccines.

Background To protect infants aged <2 months against pertussis, the United States recommends Tdap (tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis) vaccination during each pregnancy. Data are limited on the strategy's effectiveness against pertussis in infants aged ≥2 months. Methods Pertussis case infants aged 2 to <6 months with cough onset between 1 January 2011 and 31 December 2014 were identified in 6 US states. Controls were 2 to <6 months of age, hospital matched, and selected by birth certificate. Mothers were interviewed to collect demographic and healthcare information. Provider-verified vaccination history was obtained for infants and mothers. Adjusted odds ratios (aORs) were calculated using conditional logistic regression; overall vaccine effectiveness (VE) was estimated as (1 − aOR)×100. To describe maternal Tdap VE modified by infant DTaP (diphtheria and tetanus toxoids and acellular pertussis) doses, case-control sets were unmatched, and a time-to-event analysis was conducted through a generalized linear mixed model. Results A total of 335 cases and 927 controls were enrolled. The overall adjusted VE estimate for Tdap during pregnancy was 45.6% (95% confidence interval [CI], 5.8%–68.5%) and increased slightly, but not significantly, against infant hospitalization (55.7% [−116.8% to 90.9%]). Although point estimates were not significant, VE was modified by infant DTaP doses (58.8% [95% CI, −6.0% to 84.0%] for 0 DTaP doses, 30.5% [−21.4% to 60.2%] for 1 dose, and 3.2% [−170.8% to 65.4%] for 2 doses). Conclusions Our study suggests that there is some benefit of maternal Tdap vaccination beyond the first 2 months of life, however, on-time vaccination of infants remains critical to maintain protection from pertussis. [ABSTRACT FROM AUTHOR]

Meningococcal disease, caused by the bacterium Neisseria meningitidis, is a severe, life-threatening illness with rapid onset and progression of symptoms. Case-fatality rates can be as high as 10%-20% among treated [...]

Background Tetanus, a life-threatening infection, has become rare in the United States since introduction of tetanus toxoid-containing vaccines (TTCVs), recommended as a childhood series followed by decennial boosters beginning at age 11–12 years; vaccination uptake is high in children but suboptimal in adults. The objective of this study was to estimate the prevalence of sero-immunity to tetanus among persons aged ≥6 years in the United States and to identify factors associated with tetanus sero-immunity. Understanding population protection against tetanus informs current and future vaccine recommendations. Methods Anti-tetanus toxoid antibody concentrations were measured for participants of the 2015–2016 National Health and Nutrition Examination Survey (NHANES) aged ≥6 years for whom surplus serum samples were available using a microsphere-based multiplex antibody capture assay. Prevalence of sero-immunity, defined as ≥0.10 IU/mL, was estimated overall and by demographic characteristics. Factors associated with tetanus sero-immunity were examined using multivariable regression. Results Overall, 93.8% of the US population aged ≥6 years had sero-protection against tetanus. Prevalence of sero-immunity was above 90% across racial/ethnic categories, sex, and poverty levels. By age, ≥ 90% had protective sero-immunity through age 69 years, but prevalence of sero-immunity declined thereafter, with 75.8% of those aged ≥80 years having protective sero-immunity. Older age (adjusted prevalence ratio [aPR]: 0.89, 95% confidence interval [CI]:.85–.92) and being born outside the United States (aPR: 0.96, 95% CI:.93–.98) were significantly associated with lower prevalence of sero-immunity. Conclusions The majority of the US population has vaccine-induced sero-immunity to tetanus, demonstrating the success of the vaccination program. [ABSTRACT FROM AUTHOR]