Tammy A. Santibanez

Recent Resurgence of Mumps in the United States

BACKGROUND The widespread use of a second dose of mumps vaccine among U.S. schoolchildren beginning in 1990 was followed by historically low reports of mumps cases. A 2010 elimination goal was established, but in 2006 the largest mumps outbreak in two decades occurred in the United States. METHODS We examined national data on mumps cases reported during 2006, detailed case data from the most highly affected states, and vaccination-coverage data from three nationwide surveys. RESULTS A total of 6584 cases of mumps were reported in 2006, with 76% occurring between March and May. There were 85 hospitalizations, but no deaths were reported; 85% of patients lived in eight contiguous midwestern states. The national incidence of mumps was 2.2 per 100,000, with the highest incidence among persons 18 to 24 years of age (an incidence 3.7 times that of all other age groups combined). In a subgroup analysis, 83% of these patients reported current college attendance. Among patients in eight highly affected states with known vaccination status, 63% overall and 84% between the ages of 18 and 24 years had received two doses of mumps vaccine. For the 12 years preceding the outbreak, national coverage of one-dose mumps vaccination among preschoolers was 89% or more nationwide and 86% or more in highly affected states. In 2006, the national two-dose coverage among adolescents was 87%, the highest in U.S. history. CONCLUSIONS Despite a high coverage rate with two doses of mumps-containing vaccine, a large mumps outbreak occurred, characterized by two-dose vaccine failure, particularly among midwestern college-age adults who probably received the second dose as schoolchildren. A more effective mumps vaccine or changes in vaccine policy may be needed to avert future outbreaks and achieve the elimination of mumps.

Chickenpox Exposure and Herpes Zoster Disease Incidence in Older Adults in the U.S.

Objectives. Exposure to varicella zoster virus through close contact with people with chickenpox was suggested to boost specific immunity, reducing the risk of herpes zoster (HZ). Since the introduction of the varicella immunization program in the U.S. in 1995, varicella morbidity has decreased substantially. This article examines incidence and risk factors associated with self-reported HZ disease and whether exposure to chickenpox within the previous decade reduces the risk of shingles in this age group. Methods. In 2004, a national random-digit dial telephone survey was used to obtain information on self-reported HZ disease, demographic characteristics, and exposure to children with chickenpox in the past decade. National estimates of the incidence of shingles disease were calculated. Results. Incidence rate of self-reported HZ was 19 per 1,000 population per year. White individuals were 3.5 times more likely to report shingles than Hispanic individuals (p<0.01). Previous exposure to chickenpox did not protect against HZ disease in this population. Seven percent of adults ≥65 years of age reported exposure to children with chickenpox in the past decade. Conclusions. Incidence of HZ among individuals ≥65 years of age in the U.S. may be higher than previously described in the literature, with whites being at higher risk for the disease. Currently, the potential contribution of exposure to chickenpox as a mechanism for maintaining cell-mediated immunity against HZ may be limited to a small percentage of the population. Vaccination against HZ may represent the best means of decreasing this disease burden.

Influenza Vaccine Effectiveness Against Pediatric Deaths: 2010–2014

This study estimates influenza VE against deaths among children with and without underlying high-risk medical conditions by using a case–cohort approach. BACKGROUND AND OBJECTIVES: Surveillance for laboratory-confirmed influenza-associated pediatric deaths since 2004 has shown that most deaths occur in unvaccinated children. We assessed whether influenza vaccination reduced the risk of influenza-associated death in children and adolescents. METHODS: We conducted a case–cohort analysis comparing vaccination uptake among laboratory-confirmed influenza-associated pediatric deaths with estimated vaccination coverage among pediatric cohorts in the United States. Case vaccination and high-risk status were determined by case investigation. Influenza vaccination coverage estimates were obtained from national survey data or a national insurance claims database. We estimated odds ratios from logistic regression comparing odds of vaccination among cases with odds of vaccination in comparison cohorts. We used Bayesian methods to compute 95% credible intervals (CIs) for vaccine effectiveness (VE), calculated as (1 − odds ratio) × 100. RESULTS: From July 2010 through June 2014, 358 laboratory-confirmed influenza-associated pediatric deaths were reported among children aged 6 months through 17 years. Vaccination status was determined for 291 deaths; 75 (26%) received vaccine before illness onset. Average vaccination coverage in survey cohorts was 48%. Overall VE against death was 65% (95% CI, 54% to 74%). Among 153 deaths in children with underlying high-risk medical conditions, 47 (31%) were vaccinated. VE among children with high-risk conditions was 51% (95% CI, 31% to 67%), compared with 65% (95% CI, 47% to 78%) among children without high-risk conditions. CONCLUSIONS: Influenza vaccination was associated with reduced risk of laboratory-confirmed influenza-associated pediatric death. Increasing influenza vaccination could prevent influenza-associated deaths among children and adolescents.

Differential Effects of the DTaP and MMR Vaccine Shortages on Timeliness of Childhood Vaccination Coverage

OBJECTIVES We determined the effect of diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP) and measles, mumps, rubella (MMR) vaccine shortages on timeliness of the third dose of DTaP (DTaP3), the fourth dose of DTaP (DTaP4), and the first dose of MMR (MMR1) among subgroups of preschool children. METHODS Data from the 2001 and 2002 National Immunization Surveys were analyzed. Children age-eligible to receive DTaP3, DTaP4, or MMR1 during the shortages were considered subject to the shortage, and those not age-eligible were not subject to the shortage; timeliness of vaccinations was compared. RESULTS Among children vaccinated only at public clinics, children residing outside metropolitan statistical areas, and children in the Southern Census Region, those age-eligible to receive DTaP4 during the shortage were less likely to be vaccinated by 19 months of age than children not subject to the shortage. CONCLUSIONS There was notable disparity in the effects of the recent vaccine shortages; children vaccinated only in public clinics, in rural areas, or in the Southern United States were differentially affected by the shortages.

Effects of a nationwide Hib vaccine shortage on vaccination coverage in the United States

BACKGROUND A shortage of Haemophilus influenzae type b (Hib) vaccine that occurred in the United States during December 2007 to September 2009 resulted in an interim recommendation to defer the booster dose, but to continue to vaccinate as recommended with the primary series during the first year of life. OBJECTIVES To quantify effects of the Hib shortage on vaccination coverage and to determine if any demographic subgroups were disproportionately affected. METHODS Data from the 2009 National Immunization Survey (NIS) were divided based on childs age at the onset of the shortage. Comparisons were made in primary series coverage by 9 months between children <7 months versus ≥7 months at the start of the shortage. Comparisons in primary series plus booster dose completion by 19 months were made between children who were <12 months versus ≥12 months at the start of the shortage. RESULTS Nationally, there was a difference in Hib primary series completion by 9 months among children age <7 months versus ≥7 months at the start of the shortage (73.9% versus 81.2%, P<0.001). There was a large difference in the percentage of children fully vaccinated with the primary series plus booster dose by 19 months among children age <12 months versus ≥12 months at the start of the shortage (39.5% versus 66.0%, P<0.001). There were differential effects of the shortage on primary series coverage among states and for some demographic characteristics. CONCLUSIONS As expected booster dose coverage was reduced consistent with interim recommendations, but primary series coverage was also reduced by 7 percentage points nationally.

Trends in childhood influenza vaccination coverage--U.S., 2004-2012.

Objective. We compared estimates of childhood influenza vaccination coverage by health status, age, and racial/ethnic group across eight consecutive influenza seasons (2004 through 2012) based on two survey systems to assess trends in childhood influenza vaccination coverage in the U.S. Methods. We used National Health Interview Survey (NHIS) and National Immunization Survey-Flu (NIS-Flu) data to estimate receipt of at least one dose of influenza vaccination among children aged 6 months to 17 years based on parental report. We computed estimates using Kaplan-Meier survival analysis methods. Results. Based on the NHIS, overall influenza vaccination coverage with at least one dose of influenza vaccine among children increased from 16.2% during the 2004–2005 influenza season to 47.1% during the 2011–2012 influenza season. Children with health conditions that put them at high risk for complications from influenza had higher influenza vaccination coverage than children without these health conditions for all the seasons studied. In seven of the eight seasons studied, there were no significant differences in influenza vaccination coverage between non-Hispanic black and non-Hispanic white children. Influenza vaccination coverage estimates for children were slightly higher based on NIS-Flu data compared with NHIS data for the 2010–2011 and 2011–2012 influenza seasons (4.1 and 4.4 percentage points higher, respectively); both NIS-Flu and NHIS estimates had similar patterns of decreasing vaccination coverage with increasing age. Conclusions. Although influenza vaccination coverage among children continued to increase, by the 2011–2012 influenza season, only slightly less than half of U.S. children were vaccinated against influenza. Much improvement is needed to ensure all children aged ≥6 months are vaccinated annually against influenza.

Influenza vaccination coverage of Vaccine for Children (VFC)-entitled versus privately insured children, United States, 2011–2013

BACKGROUND The Vaccines for Children (VFC) program provides vaccines at no cost to children who are Medicaid-eligible, uninsured, American Indian or Alaska Native (AI/AN), or underinsured and vaccinated at Federally Qualified Health Centers or Rural Health Clinics. The objective of this study was to compare influenza vaccination coverage of VFC-entitled to privately insured children in the United States, nationally, by state, and by selected socio-demographic variables. METHODS Data from the National Immunization Survey-Flu (NIS-Flu) surveys were analyzed for the 2011-2012 and 2012-2013 influenza seasons for households with children 6 months-17 years. VFC-entitlement and private insurance status were defined based upon questions asked of the parent during the telephone interview. Influenza vaccination coverage estimates of children VFC-entitled versus privately insured were compared by t-tests, both nationally and within state, and within selected socio-demographic variables. RESULTS For both seasons studied, influenza coverage for VFC-entitled children did not significantly differ from coverage for privately insured children (2011-2012: 52.0%±1.9% versus 50.7%±1.2%; 2012-2013: 56.0%±1.6% versus 57.2%±1.2%). Among VFC-entitled children, uninsured children had lower coverage (2011-2012: 38.9%±4.7%; 2012-2013: 44.8%±3.5%) than Medicaid-eligible (2011-2012: 55.2%±2.1%; 2012-2013: 58.6%±1.9%) and AI/AN children (2011-2012: 54.4%±11.3%; 2012-2013: 54.6%±7.0%). Significant differences in vaccination coverage among VFC-entitled and privately insured children were observed within some subgroups of race/ethnicity, income, age, region, and living in a metropolitan statistical area principle city. CONCLUSIONS Although finding few differences in influenza vaccination coverage among VFC-entitled versus privately insured children was encouraging, nearly half of all children were not vaccinated for influenza and coverage was particularly low among uninsured children. Additional public health interventions are needed to ensure that more children are vaccinated such as a strong recommendation from health care providers, utilization of immunization information systems, provider reminders, standing orders, and community-based interventions such as educational activities and expanded access to vaccination services.

Socio-demographic differences in opinions about 2009 pandemic influenza A (H1N1) and seasonal influenza vaccination and disease among adults during the 2009–2010 influenza season

Background  In April 2009, a novel influenza A virus emerged in the United States. By the end of July, influenza A (H1N1) 2009 monovalent (2009 H1N1) vaccine had been developed, licensed, and recommended by the Advisory Committee on Immunization Practices. Initial target groups for vaccination were identified and the first vaccine was publicly available in early October 2009.

Complete Influenza Vaccination Trends for Children Six to Twenty-Three Months.

OBJECTIVE: Prevention of influenza among infants and young children is a public health priority because of their high risk for influenza-related complications. Depending on a child’s age and previous influenza vaccination history, they are recommended to receive either 1 dose or 2 doses of influenza vaccine to be considered fully vaccinated against influenza for the season. We compared estimates of full (complete) influenza vaccination coverage of children 6 to 23 months across 10 consecutive influenza seasons (2002–2012), by race/ethnicity, age group, and by number of doses required to be fully vaccinated given child’s vaccination history. METHODS: National Immunization Survey data were used to estimate full influenza vaccination status among children 6 to 23 months on the basis of provider report. Estimates were computed by using Kaplan-Meier survival analysis methods. RESULTS: Full influenza vaccination coverage among children 6 to 23 months increased from 4.8% in the 2002–2003 influenza season to 44.7% in the 2011–2012 season. In all 10 influenza seasons studied, non-Hispanic black children and Hispanic children had lower full influenza vaccination coverage than non-Hispanic white children. For all 10 influenza seasons, full influenza vaccination coverage was higher among children requiring only 1 dose compared with those requiring 2 doses. CONCLUSIONS: Less than half of children 6 to 23 months in the United States, and an even a smaller percentage of Hispanic and non-Hispanic black children, are fully vaccinated against influenza. More implementation of evidence-based strategies that increase the percentage of children who are fully vaccinated is needed.

Place of influenza vaccination among children--United States, 2010-11 through 2013-14 influenza seasons.

BACKGROUND Studies are published on settings adults receive influenza vaccination but few have reported on settings children are vaccinated and how this might be changing over time or vary by socio-demographics. METHODS Data from the National Immunization Survey-Flu were analyzed to assess place of influenza vaccination among vaccinated children 6 months-17 years during the 2010-11, 2011-12, 2012-13, and 2013-14 influenza seasons. The percentage of children vaccinated at each place was calculated overall and by age, race/ethnicity, income, and Metropolitan Statistical Area (MSA). RESULTS The places children received influenza vaccination varied little over four recent influenza seasons. From the 2010-11 through 2013-14 influenza seasons the percentage of vaccinated children receiving influenza vaccination at a doctors office was 64.1%, 65.1%, 65.3%, and 65.3%, respectively with no differences from one season to the next. Likewise, for vaccination at clinics or health centers (17.8%, 17.5%, 17.0%. 18.0%), health departments (3.2%, 3.6%, 3.0%, 2.8%), and other non-medical places (1.6%, 1.4%, 1.2%, 1.1%), there were no differences from one season to the next. There were some differences for vaccinations at hospitals, pharmacies, and schools. There was considerable variability in the place of influenza vaccination by age, race/ethnicity, income, and MSA. Fewer Hispanic children were vaccinated at a doctors office than black, white, and other or multiple race children and fewer black children and children of other or multiple races were vaccinated at a doctors office than white children. More children at or below the poverty level were vaccinated at a clinic or health center than all of the other income groups. CONCLUSION Most vaccinated children receive their influenza vaccination at a doctors office. Place of vaccination changed little over four recent influenza seasons. Large variability in place of vaccination exists by age, race/ethnicity, income, and MSA. Monitoring place of vaccination can help shape future immunization programs.