Vaccine Coverage at 36 Months and 7 Years by Parental Birth Country, Washington State.

BACKGROUND AND OBJECTIVES: Ensuring equitable vaccination access for immigrant communities is critical for guiding efforts to redress health disparities, but vaccine coverage data are limited. We evaluated childhood vaccination coverage by parental birth country (PBC) through the linkage of Washington State Immunization Information System data and birth records. METHODS: We conducted a retrospective cohort evaluation of children born in Washington from January 1, 2006 to November 12, 2019. We assessed up-to-date vaccination coverage status for measles, mumps, and rubella (MMR), diphtheria, tetanus, and pertussis (DTaP), and poliovirus vaccines at ages 36 months and 7 years. Children with ≥1 parent(s) born in selected non-US countries were compared with children with 2 US-born parents, using Poisson regression models to provide prevalence ratios. RESULTS: We identified 902 909 eligible children, of which 24% had ≥1 non-US-born parent(s). Vaccination coverage at 36 months by PBC ranged from 41.0% to 93.2% for ≥1 MMR doses and ≥3 poliovirus doses and 32.6% to 86.4% for ≥4 DTaP doses. Compared with children of US-born parents, the proportion of children up to date for all 3 vaccines was 3% to 16% higher among children of Filipino-, Indian-, and Mexican-born parents and 33% to 56% lower among children of Moldovan-, Russian-, and Ukrainian-born parents. Within-PBC coverage patterns were similar for all vaccines with some exceptions. Similar PBC-level differences were observed at 7 years of age. CONCLUSIONS: The linkage of public health data improved the characterization of community-level childhood immunization outcomes. The findings provide actionable information to understand community-level vaccination determinants and support interventions to enhance vaccine coverage.

Hepatitis C Screening and Antibody Prevalence Among Newly Arrived Refugees to the United States, 2010-2017.

Six refugee screening sites collaborated to estimate the prevalence of hepatitis C virus (HCV) antibodies among newly arrived refugees in the United States from 2010 to 2017, identify demographic characteristics associated with HCV antibody positivity, and estimate missed HCV antibody-positive adults among unscreened refugees. We utilized a cross-sectional study to examine HCV prevalence among refugees (N = 144,752). A predictive logistic regression model was constructed to determine the effectiveness of current screening practices at identifying cases. The prevalence of HCV antibodies among the 64,703 refugees screened was 1.6%. Refugees from Burundi (5.4%), Moldova (3.8%), Democratic Republic of Congo (3.2%), Burma (2.8%), and Ukraine (2.0%) had the highest positivity among refugee arrivals. An estimated 498 (0.7%) cases of HCV antibody positivity were missed among 67,787 unscreened adults. The domestic medical examination represents an opportunity to screen all adult refugees for HCV to ensure timely diagnosis and treatment.

Mortality Rate and Causes of Death Among Refugees Resettled in Washington State, 2006-2016.

Cause of death among refugees resettled in the United States is not well documented. This evaluation determined cause of death among refugees who resettled to and died in Washington State. Records of refugees who arrived in Washington State from 2006 to 2016 were linked to state death records for the same period. Rates and proportions of death were calculated and compared to those for all Washingtonians. From 2006 to 2016, 171 of 30,243 refugees (0.6%) resettled to and died in Washington. The age-adjusted all-cause mortality rate was 3.93 (95% CI 3.12-4.75) per 1000 refugees, compared to 6.98 (95% CI 6.96-7.00) per 1000 Washingtonians. Malignant neoplasms and heart disease were the leading causes of death for both refugees and Washingtonians. Determining cause of death among refugee populations can identify emerging trends in mortality. This information can be used to help inform disease and injury prevention interventions for refugee communities.

Parental Country of Birth and Childhood Vaccination Uptake in Washington State.

BACKGROUND: Underimmunization of certain immigrant populations can place them at high risk of experiencing vaccine-preventable disease outbreaks. METHODS: We conducted a retrospective cohort study between January 1, 2008, and May 1, 2013, among children included in the Washington State Immunization Information System. We assessed receipt of 1 or more doses of measles-containing, hepatitis A, pneumococcal, and diphtheria-tetanus-acellular pertussis-containing vaccines between 12 and 23 months of age. We compared children with 1 or more parents born in Somalia, Ukraine, Russia, Mexico, or India to children with 2 parents born in the United States. Poisson regression models with robust SEs were used to provide prevalence ratios adjusted for maternal education and number of prenatal visits. RESULTS: We identified 277 098 children, including 65 466 with foreign-born parents. Children of Somali-born parents were less likely to be immunized against measles than children of US-born parents (prevalence ratio: 0.82; 95% confidence interval: 0.80-0.84); this decrease became more pronounced over time (P < .01). No such disparity between these groups was observed with other vaccines. Compared with children of US-born parents, children of Ukrainian-born and Russian-born parents were less likely to be immunized, whereas children of Mexican-born and Indian-born parents were more likely to be immunized with any of the specified vaccines. CONCLUSIONS: We found country-specific patterns of immunization that may reflect underlying cultural or other beliefs. Certain immigrant communities with higher rates of immunization refusal may be at risk for vaccine-preventable diseases and require new forms of public health outreach.

Tdap vaccine effectiveness in adolescents during the 2012 Washington State pertussis epidemic.

BACKGROUND: Acellular pertussis vaccines replaced whole-cell vaccines for the 5-dose childhood vaccination series in 1997. A sixth dose of pertussis-containing vaccine, tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis, adsorbed (Tdap), was recommended in 2005 for adolescents and adults. Studies examining Tdap vaccine effectiveness (VE) among adolescents who have received all acellular vaccines are limited. METHODS: To assess Tdap VE and duration of protection, we conducted a matched case-control study during the 2012 pertussis epidemic in Washington among adolescents born during 1993-2000. All pertussis cases reported from January 1 through June 30, 2012, in 7 counties were included; 3 controls were matched by primary provider clinic and birth year to each case. Vaccination histories were obtained through medical records, the state immunization registry, and parent interviews. Participants were classified by type of pertussis vaccine received on the basis of birth year: a mix of whole-cell and acellular vaccines (1993-1997) or all acellular vaccines (1998-2000). We used conditional logistic regression to calculate odds ratios comparing Tdap receipt between cases and controls. RESULTS: Among adolescents who received all acellular vaccines (450 cases, 1246 controls), overall Tdap VE was 63.9% (95% confidence interval [CI]: 50% to 74%). VE within 1 year of vaccination was 73% (95% CI: 60% to 82%). At 2 to 4 years postvaccination, VE declined to 34% (95% CI: -0.03% to 58%). CONCLUSIONS: Tdap protection wanes within 2 to 4 years. Lack of long-term protection after vaccination is likely contributing to increases in pertussis among adolescents.

Molecular epidemiology of the pertussis epidemic in Washington State in 2012.

Although pertussis disease is vaccine preventable, Washington State experienced a substantial rise in pertussis incidence beginning in 2011. By June 2012, the reported cases reached 2,520 (37.5 cases per 100,000 residents), a 1,300% increase compared with the same period in 2011. We assessed the molecular epidemiology of this statewide epidemic using 240 isolates collected from case patients reported from 19 of 39 Washington counties during 2012 to 2013. The typing methods included pulsed-field gel electrophoresis (PFGE), multilocus variable number tandem repeat analysis (MLVA), multilocus sequence typing (MLST), and pertactin gene (prn) mutational analysis. Using the scheme PFGE-MLVA-MLST-prn mutations-Prn deficiency, the 240 isolates comprised 65 distinct typing profiles. Thirty-one PFGE types were found, with the most common types, CDC013 (n = 51), CDC237 (n = 44), and CDC002 (n = 42), accounting for 57% of them. Eleven MLVA types were observed, mainly comprising type 27 (n = 183, 76%). Seven MLST types were identified, with the majority of the isolates typing as prn2-ptxP3-ptxA1-fim3-1 (n = 157, 65%). Four different prn mutations accounted for the 76% of isolates exhibiting pertactin deficiency. PFGE provided the highest discriminatory power (D = 0.87) and was found to be a more powerful typing method than MLVA and MLST combined (D = 0.67). This study provides evidence for the continued predominance of MLVA 27 and prn2-ptxP3-ptxA1 alleles, along with the reemergence of the fim3-1 allele. Our results indicate that the Bordetella pertussis population causing this epidemic was diverse, with a few molecular types predominating. The PFGE, MLVA, and MLST profiles were consistent with the predominate types circulating in the United States and other countries. For prn, several mutations were present in multiple molecular types.

Measles outbreak associated with adopted children from China--Missouri, Minnesota, and Washington, July 2013.

On July 5, 2013, CDC was notified of two cases of laboratory-confirmed measles in recently adopted children from an orphanage in Henan Province, China. To find potentially exposed persons, CDC collaborated with state and local health departments, the children's adoption agency, and airlines that carried the adoptees. Two additional measles cases were identified, one in a family member of an adoptee and one in a third adopted child from China. To prevent further importation of measles, CDC worked with health officials in China, including "panel physicians" contracted by the U.S. Department of State to conduct the overseas medical examinations required for all immigrants and refugees bound for the United States. The following measures were recommended: 1) all adoptees examined at panel physician facilities should be screened for fever and rash illness, 2) measles immunity should be ensured among all adoptees from Henan Province who are scheduled for imminent departure to the United States, and 3) all children at the orphanage in Henan Province should be evaluated for measles. This report summarizes the results of the outbreak investigation and underscores the importance of timely routine vaccination for all international adoptees.

Effectiveness of pentavalent and monovalent rotavirus vaccines in concurrent use among US children <5 years of age, 2009-2011.

BACKGROUND: We assessed vaccine effectiveness (VE) for RotaTeq (RV5; 3 doses) and Rotarix (RV1; 2 doses) at reducing rotavirus acute gastroenteritis (AGE) inpatient and emergency department (ED) visits in US children. METHODS: We enrolled children <5 years of age hospitalized or visiting the ED with AGE symptoms from November 2009-June 2010 and from November 2010-June 2011 at 7 medical institutions. Fecal specimens were tested for rotavirus by enzyme immunoassay and genotyped. Vaccination among laboratory-confirmed rotavirus cases was compared with rotavirus-negative AGE controls. Regression models calculated VE estimates for each vaccine, age, ethnicity, genotype, and clinical setting. RESULTS: RV5-specific analyses included 359 rotavirus cases and 1811 rotavirus-negative AGE controls. RV1-specific analyses included 60 rotavirus cases and 155 rotavirus-negative AGE controls. RV5 and RV1 were 84% (95% confidence interval [CI], 78%-88%) and 70% (95% CI, 39%-86%) effective, respectively, against rotavirus-associated ED visits and hospitalizations combined. By clinical setting, RV5 VE against ED and inpatient rotavirus-associated visits was 81% (95% CI, 70%-84%) and 86% (95% CI, 74%-91%), respectively. RV1 was 78% (95% CI, 46%-91%) effective against ED rotavirus disease; study power was insufficient to evaluate inpatient RV1 VE. No waning of immunity was evident during the first 4 years of life for RV5, nor during the first 2 years of life for RV1. RV5 provided genotype-specific protection against each of the predominant strains (G1P[8], G2P[4], G3P[8], G12P[8]), while RV1 VE was statistically significant for the most common genotype, G3P[8]. CONCLUSIONS: Both RV5 and RV1 significantly protected against medically attended rotavirus gastroenteritis in this real-world assessment.

Cost effectiveness of child pneumococcal conjugate vaccination in GAVI-eligible countries.

Policy-makers increasingly rely on cost-effectiveness analysis, in addition to clinical effectiveness, when considering the introduction of new childhood vaccines. A previous analysis determined vaccination of infants with 7-valent pneumococcal conjugate vaccine (PCV) to be highly cost effective in preventing child mortality in countries eligible for financial support from the Global Alliance for Vaccines and Immunization (GAVI). We aimed to update this analysis by incorporating recent data on global disease burden, indirect effects and higher valency vaccines. Decision analytic models were built using an incidence-based approach in order to evaluate a three-dose vaccination schedule of infants in 72 GAVI-eligible countries over a 10-year programme. Seven-, 10- and 13-valent vaccine formulations were each compared with no vaccination. Depending on the formulation used, PCV could avert 294 000-603 000 deaths and 9.3-17.6 million disability-adjusted life-years (DALY) annually. The majority (91%) of the DALYs averted would be through the vaccine's direct effects in children under-5. Using WHO thresholds and a negotiated average dose cost, PCV would be highly cost effective in 69 of 72 GAVI-eligible countries. This finding was robust when assumptions regarding disease epidemiology and vaccine-related effects were varied in sensitivity analyses. The current analysis supports PCV introduction in GAVI-eligible countries owing to its potential to avert substantial numbers of deaths at relatively low incremental costs.

Cost effectiveness of child pneumococcal conjugate vaccination in middle-income countries.

Policy-makers require information on the potential benefits of and economic case for pneumococcal conjugate vaccination in middle-income countries. We built decision analysis models to evaluate a three-dose infant series of the 7-, 10- or 13-valent pneumococcal conjugate vaccines in 77 middle-income countries compared with no vaccination, accounting for direct protection of vaccinated children as well as herd protection and serotype replacement in unvaccinated children and adults. Over 10 years, pneumococcal vaccination would prevent at least 11.0 million cases and 314 000 deaths in children under-5, one-third of the pneumonia and invasive disease cases and deaths that would occur in this age group without vaccination. Herd protection would prevent 3.1 million cases and 163 000 deaths in older children and adults. A total of 11.1 million discounted disability-adjusted life-years (DALY) would be averted. At a dose cost of $10 for lower- middle-income and $20 for upper-middle-income countries, the net pooled (for all countries together) discounted vaccination cost would be $18.1 billion ($1600 per DALY averted). Vaccination would be cost effective for 72 countries with the 7-valent vaccine and for all countries with the 10- or 13-valent vaccines. The economic case for vaccination is compelling for middle-income countries.

Disappearance of vaccine-type invasive pneumococcal disease and emergence of serotype 19A in a minority population with a high prevalence of human immunodeficiency virus and low childhood immunization rates.

We analyzed the epidemiology of invasive pneumococcal disease (IPD) following introduction of pneumococcal conjugated vaccine in an urban population with a 2% human immunodeficiency virus (HIV) prevalence and history of low childhood immunization rates. We observed near-elimination of vaccine-type IPD. Substantial disease remains due to non-vaccine-type pneumococci, highlighting the need to increase pneumococcal immunization among HIV-infected adults.

Development of a Web-based questionnaire to collect exposure and symptom data in children and adolescents with asthma.

BACKGROUND: Questionnaires are an important component of epidemiologic studies. Maintaining compliance in longitudinal studies is a challenge, particularly from children and adolescents. OBJECTIVE: To implement a Web-based questionnaire for children and adolescents with asthma for daily self-completion, minimizing recall bias and maximizing compliance. METHODS: We determined symptoms, exposure to asthma triggers, peak expiratory flow rate, and medications taken, including dose and dose time. The Web-based system can be less time-consuming and a source of fewer errors than paper questionnaires and permits review of the data and compliance during the study. The Web programming of the questionnaire included branching, so that questions deemed irrelevant based on a previous response were not presented to participants, minimizing the completion time. RESULTS: Sixty-four students with asthma participated nearly daily for between 2 and 4 months. Financial incentives for the participants were calculated in real time based on completion rates. Monitoring of the subject's completion included an extensive administrative hierarchical alert system, enabling the staff to target individuals who fell behind in entries and needed the most encouragement. CONCLUSIONS: Similar compliance and completion rates were obtained using the Web-based questionnaire as reported for smaller paper questionnaires by parents of children. The Web-based system provides a mechanism to obtain daily responses directly from an age group not often accessible by traditional questionnaire approaches.

Invasive pneumococcal disease in an underimmunized, high HIV prevalence population.

OBJECTIVE: To describe the epidemiology of invasive pneumococcal disease (IPD) in a predominantly minority population with low childhood immunization rates and high HIV prevalence, during the early childhood pneumococcal vaccine (PCV7) era. METHODS: A retrospective cases series analysis of 131 patients diagnosed with IPD at University Hospital in Newark, NJ from 2000 through 2005, and who had their pneumococcal isolates serotyped, was conducted. Changes in IPD over time were analyzed with the Cochran-Armitage test and linear regression. Multivariate logistic regression was conducted to determine risk factors for non-vaccine type IPD. RESULTS: Ninety-two percent of cases occurred in older children (>or=5 years) and adults, with 53.4% occurring in the 34-49 year-old age group. 90% of cases were black and 48% were HIV-infected. Among cases five years or older, there was a significant decrease in the proportion of IPD caused by vaccine serotypes (2000: 45.5%, 2001: 50.0%, 2002: 31.8%, 2003: 30.0%, 2004: 0.0%, 2005: 0.0%; p<0.0005). Concomitantly, PCV7 immunization rates among Newark infants increased (2002: 30.5%, 2003: 58.1%, 2004: 70.9%, 2005: 75.6%). Risk factors for non-vaccine type IPD included year of diagnosis and older male. CONCLUSION: At-risk populations, with high HIV prevalence and relatively low infant PCV7 immunization rates, may still be benefiting from PCV7-related herd protection effects.