Global routine vaccination coverage, 2009

The widespread use of vaccines has greatly improved global public health, preventing millions of childhood hospitalizations and deaths each year. Vaccination of children also is projected to avert adult deaths through the prevention of hepatitis B (HepB) virus--related chronic liver disease and liver cancer and human papilloma virus--related cervical cancer. When the World Health Organization (WHO) began the Expanded Programme on Immunization in 1974, <5% of the world's children had been fully vaccinated with bacille Calmette-Guérin (BCG), diphtheria-tetanus-pertussis (DTP) vaccine, oral poliovirus vaccine, and measles-containing vaccine (MCV) during the first year of life. Since then, increased vaccination coverage has resulted in substantial reductions in morbidity and mortality, including a >99% decline in polio incidence since 1988, with eradication on the horizon, and a 78% decline in measles-associated mortality from 2000 to 2008 With the introduction of Haemophilus influenzae type b (Hib) vaccine, HepB vaccine, pneumococcal conjugate vaccine (PCV), and rotavirus vaccine into many countries' routine vaccination schedules, further reductions in morbidity and mortality are expected. However, based on an annual global birth cohort of approximately 130 million, an estimated 23 million infants worldwide still do not receive the benefits of routine vaccination (i.e., 3 doses of DTP during the first year of life). The Global Immunization Vision and Strategy (GIVS), developed in 2005 by WHO and UNICEF, assists countries in strengthening immunization programs and vaccinating more persons. GIVS aims to achieve 90% national 3-dose DTP (DTP3) coverage by age 12 months in all countries, and 80% coverage in every district or equivalent administrative unit by 2010 (and to sustain these levels through 2015). This report summarizes global routine vaccination coverage during 2000--2009 and progress toward achieving GIVS goals.     

Vaccination coverage among children in kindergarten--United States, 2006-07 school year

Healthy People 2010 objectives include increasing vaccination coverage among children in kindergarten and first grade (objective 14-23). For these children, the target is >/=95% vaccination coverage for the following: hepatitis B vaccine; diphtheria and tetanus toxoids and pertussis vaccine, diphtheria and tetanus toxoids and acellular pertussis vaccine, or diphtheria and tetanus toxoids vaccine (DTP/DTaP/DT); poliovirus vaccine; measles, mumps, and rubella (MMR) vaccine; and varicella vaccine. To assess progress toward national goals and determine vaccination coverage among children in kindergarten, data were analyzed from reports submitted to CDC by 49 states and the District of Columbia (DC) for the 2006-07 school year. This report summarizes findings from that analysis, which indicated that approximately 75% of states have reached the 2010 objective of at least 95% coverage for all of the vaccines recommended by the Advisory Committee on Immunization Practices (ACIP) for children in kindergarten. These results underscore the effectiveness of school-entry requirements in increasing vaccination coverage but highlight a need for more standardized vaccination reporting among states.     

Vaccination coverage among children entering school--United States, 2005-06 school year

One of the national health objectives for 2010 is to achieve and sustain > or =95% vaccination coverage among children in kindergarten through first grade for the following vaccines: hepatitis B vaccine; diphtheria and tetanus toxoids and pertussis vaccine, diphtheria and tetanus toxoids and acellular pertussis vaccine, or diphtheria and tetanus toxoids vaccine (DTP/DTaP/DT); poliovirus (polio) vaccine; measles, mumps, and rubella vaccines; and varicella vaccine. To determine vaccination coverage among children entering kindergarten, data were analyzed from reports submitted to CDC by states and the District of Columbia (DC) for the 2005-06 school year. This report summarizes the results of that analysis, which indicated that coverage for each vaccine was reported to have exceeded 95% in more than half of the states.     

Vaccination coverage estimates for selected counties: achievement of Healthy People 2010 goals and association with indices of access to care, economic conditions, and demographic composition

OBJECTIVES: We provided vaccination coverage estimates for 181 counties; evaluated the extent to which Healthy People 2010 (HP 2010) vaccination coverage objectives were achieved; and examined how variations in those estimates depend on access to care and economic conditions. METHODS: We analyzed data for 24,031 children aged 19 to 35 months sampled from the 2004 and 2005 National Immunization Survey. RESULTS: Children living in the 181 counties represented 49% of all the 19- to 35-month-old children living in the U.S. None of the 181 counties had coverage for the polio, measles-mumps-rubella, Haemophilus influenzae type B, and hepatitis B vaccines that was significantly lower than the HP 2010 objective of 90% coverage. However, as many as 30.4% of the counties did not achieve the HP 2010 objective for diphtheria, tetanus toxoids, and acellular pertussis or diphtheria and tetanus toxoids and pertussis (DtaP/DTP), and as many as 6.6% did not achieve the goal for varicella (VAR). If children who received three doses of DTaP/DTP had received a final fourth dose, and if all children had received one dose of VAR, all of the 181 counties would have achieved the HP 2010 vaccination coverage target of 80% for the entire 4:3:1:3:3:1 vaccination series. Factors found to be associated with low county-level vaccination coverage rates were correlates of poverty, and factors found to be associated with high county-level vaccination coverage rates were correlates of access to pediatric services. CONCLUSIONS: HP 2010 vaccination coverage goals for all 181 counties can be achieved by improving vaccination coverage for only two vaccines. Those goals may be achieved most efficiently by targeting interventions in counties where indices of poverty are high or where access to pediatric services is low.     

National, state, and urban area vaccination coverage levels among children aged 19-35 months--United States, 1998.

PROBLEM/CONDITION: High vaccination levels in the population are necessary to decrease disease transmission and prevent disease; therefore, an important component of the U.S. vaccination program is the assessment of vaccination coverage. Current goals are for > or = 90% coverage with recommended vaccines during the first 2 years of life. REPORTING PERIOD: January-December 1998. DESCRIPTION OF SYSTEMS: The National Immunization Survey (NIS) is an ongoing, random-digit-dialed telephone survey that gathers vaccination coverage data for children aged 19-35 months in all 50 states and 28 urban areas. Vaccination coverage rates derived from NIS data are adjusted statistically for households with multiple telephone lines, household nonresponse, the proportion of households without telephones, and vaccination provider nonresponse. The results were also adjusted to match the known total population of children in each survey area. RESULTS: On the basis of NIS data, national coverage was > or = 90% for three doses of poliovirus vaccine (Polio), three doses of Haemophilus influenzae type b vaccine (Hib), and one dose of measles-containing vaccine (MCV). Coverage was the highest ever reported for four doses of any diphtheria and tetanus toxoids and pertussis vaccine (DTP) (i.e., diphtheria and tetanus toxoids and pertussis vaccine, diphtheria and tetanus toxoids [DT], or diphtheria and tetanus toxoids and acellular pertussis vaccine [DTaP]) (83.9%), three doses of hepatitis B vaccine (Hep B, 87.0%), and one dose of varicella vaccine (43.2%). The number of states achieving the > or = 90% goal was 47 for three doses of Hib, 40 for three doses of Polio, 40 for one dose of MCV, nine for three doses of Hep B, and seven for four doses of DTP. Proportionally fewer urban areas achieved the > or = 90% goal: 23 of 28 for three doses of Hib, 13 for three doses of Polio, 16 for one dose of MCV, five for three doses of Hep B, and one for four doses of DTP. No state or urban area has yet achieved the > or = 90% goal for varicella. INTERPRETATION: Findings from the 1998 NIS indicate that national vaccination coverage levels for routinely recommended childhood vaccines are at the highest levels ever reported. However, substantial variation in coverage remains at the state and urban area levels. PUBLIC HEALTH ACTIONS: The public health community and vaccination providers in areas with low coverage should intensify their efforts to implement recommended strategies for increasing vaccination coverage to ensure that children are equally well protected throughout the United States.     

Vaccination coverage among children enrolled in Head Start programs and licensed child care centers and entering school--United States and selected reporting areas, 1999-2000 school year

Undervaccinated children enrolled in child care centers and schools are vulnerable to outbreaks of vaccine-preventable disease. One of the national health objectives for 2010 is to maintain > or = 95% vaccination coverage among children attending licensed child care centers and kindergarten through postsecondary school (objective 14-23). To identify children who have not been vaccinated in compliance with state law, all states, five large cities (Chicago, Houston, New York, Philadelphia, and San Antonio), and eight territories conduct annual vaccination assessment surveys of coverage with basic vaccines among children enrolled in the Head Start program, enrolled in licensed child care centers, and entering kindergarten or first grade. These survey results are aggregated and analyzed by CDC to estimate national vaccination coverage. This report summarizes estimated coverage with the basic vaccines: > or = 3 doses of poliovirus vaccine, > or = 3 tetanus containing doses (diphtheria and tetanus toxoids and acellular pertussis vaccine [DTaP]), diphtheria and tetanus toxoids (DT), or tetanus toxoids (Td), and 1 dose each of measles, mumps, and rubella vaccines forthe September 1999-June 2000 school year. Results indicate that among reporting programs, the mean coverage for all vaccines was >95% for the surveyed population. However, coverage varied from state to state, and approximately 30% of states did not submit reports. High rates of vaccination coverage must be maintained to prevent transmission of vaccine-preventable disease. States should conduct yearly assessments to maintain these rates among preschool- and school-aged children.     

Food and Drug Administration approval of a fifth acellular pertussis vaccine for use among infants and young children--United States, 2002

On May 14, 2002, the Food and Drug Administration (FDA) approved for use an additional combined diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP) (DAPTACEL Aventis Pasteur, Ltd. [Toronto, Ontario]) for the first 4 doses of the diphtheria and tetanus toxoids and pertussis vaccination (DTP) series administered to infants and children aged 6 weeks-6 years (before seventh birthday). DAPTACEL is the fifth acellular pertussis vaccine to be licensed for use among infants and young children in the United States. Of these five, three (Tripedia, Infanrix, and DAPTACEL) are distributed in the United States.     

Vaccination coverage among children enrolled in Head Start programs or day care facilities or entering school.

PROBLEM/CONDITION: Undervaccinated children enrolled in day care centers and schools are vulnerable to outbreaks of vaccine-preventable diseases. A Healthy People 2000 objective is to increase to > or = 95% vaccination coverage among children attending licensed day care facilities and kindergarten through postsecondary school (objective 20.11). REPORTING PERIOD COVERED: September 1997-June 1998. DESCRIPTION OF SYSTEM: CDC's National Immunization Program administers grants to support 64 vaccination programs. These programs are in all 50 states, eight territories or jurisdictions (American Samoa, Republic of Marshall Islands, Federated States of Micronesia, Guam, Commonwealth of Northern Mariana Islands, Puerto Rico, Republic of Palau, and the U.S. Virgin Islands), five cities (Chicago, Houston, San Antonio, New York City, and Philadelphia), and the District of Columbia. Grant guidelines require annual school vaccination surveys and biennial surveys of Head Start programs and licensed day care facilities. This system constitutes the only source of nationally representative vaccination coverage estimates for these populations. RESULTS: Head Start Programs: Of the 64 reporting areas, 33 (51.6%) submitted coverage levels for children enrolled in Head Start programs. Of these, all 33 programs reported coverage levels for diphtheria and tetanus toxoids and pertussis vaccine (DTP), diphtheria and tetanus toxoids (DT), or tetanus toxoids (Td), poliovirus vaccine, and measles vaccine; and 32 reported coverage levels for mumps and rubella vaccines. Four programs reported coverage levels for the combined measles, mumps, and rubella vaccine (MMR). The mean vaccination coverage levels for the 1997-98 school year among the reporting vaccination programs were 97.8% for poliovirus vaccine (range: 80.0%-100.0%), 97.0% for DTP/DT/Td (range: 87.7%-100.0%), 93.3% for measles vaccine (range: 91.4%-100.0%), and 93.2% for mumps and rubella vaccines (range: 91.4%-100.0%). Licensed Day Care Facilities: Of the 63 reporting areas with licensed day care facilities, 38 (60.3%) submitted coverage levels for enrolled children. Of these, all 38 programs reported coverage levels for poliovirus vaccine and DTP/DT/Td, 37 reported coverage levels for measles vaccine, and 36 reported coverage levels for mumps and rubella vaccines. Four programs reported coverage levels for the combined MMR. The mean vaccination coverage levels among the reporting areas were 95.8% for poliovirus vaccine (range: 85.1%-99.8%), 95.7% for DTP/DT/Td (range: 77.6%-99.9%), 89.1% for measles vaccine (range: 78.0%-99.9%), and 89.1% for mumps and rubella vaccines (range: 78.0%-99.9%). Kindergarten/First Grade: Of the 64 reporting areas, 43 (67.2%) submitted coverage levels for children enrolled in kindergarten and first grade. Of these 43 programs, 42 reported coverage levels for poliovirus vaccine and DTP/DT/Td, and 43 reported coverage levels for measles, mumps, and rubella vaccines. Four of the 43 programs reported coverage levels for the combined MMR. The mean vaccination coverage levels among the reporting areas were 96.7% for poliovirus vaccine (range: 82.8%-99.9%), 96.7% for DTP/DT/Td (range: 82.8%-99.8%), 96.0% for measles vaccine (range: 82.8%-99.9%), and 96.5% for mumps and rubella vaccines (range: 82.8%-99.9%). INTERPRETATION: High levels of vaccination coverage among children entering school most likely result from the successful implementation of state-specific school vaccination laws, which have applied to children entering school in all states and the District of Columbia since at least 1990. All states, territories, and the District of Columbia have additional laws that require vaccination of children in licensed day care facilities. However, because a high proportion of states and territories did not submit vaccination coverage reports to CDC, these estimated means may not reflect levels for all children in the United States.     

Vaccination Coverage Disparities Between Foreign-Born and U.S.-Born Children Aged 19–35 Months,United States, 2010–2012

Healthy People 2020 targets high vaccination coverage among children. Although reductions in coverage disparities by race/ethnicity have been described, data by nativity are limited. The National Immunization Survey is a random-digit-dialed telephone survey that estimates vaccination coverage among U.S. children aged 19–35 months. We assessed coverage among 52,441 children from pooled 2010–2012 data for individual vaccines and the combined 4:3:1:3*:3:1:4 series (which includes ≥4 doses of diphtheria, tetanus, and acellular pertussis vaccine/diphtheria and tetanus toxoids vaccine/diphtheria, tetanus toxoids, and pertussis vaccine, ≥3 doses of poliovirus vaccine, ≥1 dose of measles-containing vaccine, ≥3 or ≥4 doses of Haemophilus influenzae type b vaccine (depending on product type of vaccine; denoted as 3* in the series name), ≥3 doses of hepatitis B vaccine, ≥1 dose of varicella vaccine, and ≥4 doses of pneumococcal conjugate vaccine). Coverage estimates controlling for sociodemographic factors and multivariable logistic regression modeling for 4:3:1:3*:3:1:4 series completion are presented. Significantly lower coverage among foreign-born children was detected for DTaP, hepatitis A, hepatitis B, Hib, pneumococcal conjugate, and rotavirus vaccines, and for the combined series. Series completion disparities persisted after control for demographic, access-to-care, poverty, and language effects. Substantial and potentially widening disparities in vaccination coverage exist among foreign-born children. Improved immunization strategies targeting this population and continued vaccination coverage monitoring by nativity are needed.     

Immunization coverage among predominantly Hispanic children, aged 2-3 years, in central Los Angeles

PURPOSE: To assess the immunization status of young children in a predominantly Hispanic region in and around downtown Los Angeles, and factors associated with complete immunization by age 24 months. METHODS: The information was gathered in a two-stage cluster survey with probability proportionate to estimated size (PPS) sampling of 30 clusters at the first stage, and simple random sampling of a constant number of children at the second stage. Vaccination coverage was determined by a review of the home immunization (HI) card, or of clinic records. RESULTS: Of the 270 sampled children, 91.5% were Hispanic and 6.7% were Black. Home telephone numbers were not available in 24.8% of the homes, and 34.1% reported having no health insurance. Vaccination coverage was over 90% for the first three doses of Diphtheria, tetanus toxoids and pertussis/ diphtheria, tetanus toxoids and acellular pertussis vaccine (DTP/DTaP)/Diphtheria and tetanus toxoids vaccine (DT), first two doses of poliovirus (Polio) vaccine, first dose of measles, mumps and rubella (MMR) vaccine, and first two doses of hepatitis B (Hep B) vaccine. Yet, by age 24 months, only 72.2% of the children had received the combined series of 4:3:1 (i.e., four DTP/DTaP/DT, three Polio, one MMR). This was further reduced to 64.4% for the combined series of 4:3:1:3:3 (i.e., four DTP/DTaP/ DT, three Polio, one MMR, three Haemophilus influenzae type b (Hib), three Hep B). Factors associated with completed on-time vaccination were having an HI card available during the interview and being enrolled in Supplemental Nutrition Program for Women, Infants and Children (WIC). CONCLUSIONS: While vaccination levels for individual antigens were found to be high, more emphasis needs to be placed on getting preschool children vaccinated on-time according to the Recommended Childhood Immunization Schedule.     

Vaccine preventable deaths and the Global Immunization Vision and Strategy, 2006-2015

Immunization is among the most successful and cost-effective public health interventions. Immunization programs have led to eradication of smallpox, elimination of measles and poliomyelitis in regions of the world, and substantial reductions in the morbidity and mortality attributed to diphtheria, tetanus, and pertussis. The World Health Organization (WHO) estimates that 2 million child deaths were prevented by vaccinations in 2003. Nonetheless, more deaths can be prevented through optimal use of currently existing vaccines. This report summarizes estimates of deaths attributed to vaccine-preventable diseases (VPDs) and vaccination coverage by WHO region and outlines the Global Immunization Vision and Strategy developed by WHO and the United Nations Children's Fund (UNICEF) and partners for implementation during 2006-2015.     

Evaluation of invalid vaccine doses in 31 countries of the WHO African Region

We examined (a) the fraction of and extent to which vaccinations were administered earlier than recommended (age-invalid) or with too short intervals between vaccine doses (interval-invalid) in countries of the World Health Organisation (WHO) African Region and (b) individual- and community-level factors associated with invalid vaccinations using multilevel techniques. Data from the Demographic and Health Surveys conducted in the last 10 years in 31 countries were used. Information about childhood vaccinations was based on vaccination records (n = 134,442). Invalid vaccinations (diphtheria, tetanus, pertussis [DTP1, DTP3] and measles-containing vaccine (MCV)) were defined using the WHO criteria. The median percentages of invalid DTP1, DTP3 and MCV vaccinations across all countries were 12.1% (interquartile range, 9.4–15.2%), 5.7% (5.0–7.6%), and 15.5% (10.0–18.1%), respectively. Of the invalid DTP1 vaccinations, 7.4% and 5.5% were administered at child's age of less than one and two weeks, respectively. In 12 countries, the proportion of invalid DTP3 vaccinations administered with an interval of less than two weeks before the preceding dose varied between 30% and 50%. In 13 countries, the proportion of MCV doses administered at child's age of less than six months varied between 20% and 45%. Community-level variables explained part of the variation in invalid vaccinations. Invalid vaccinations are common in African countries. Timing of childhood vaccinations should be improved to ensure an optimal protection against vaccine-preventable infections and to avoid unnecessary wastage in these economically deprived countries.     

Associated or combined vaccination of Brazilian infants with a conjugate Haemophilus influenzae type b (Hib) vaccine, a diphtheria-tetanus-whole-cell pertussis vaccine and IPV or OPV elicits protective levels of antibodies against Hib

This study investigated the immunogenicity and safety of including a Haemophilus influenzae type b vaccine (polyribosylribitol phosphate conjugated to tetanus toxoid, PRP-T) in three different vaccination schemes: (1) PRP-T reconstituted with a combined diphtheria-tetanus-pertussis-inactivated poliovirus vaccine (DTP-IPV//PRP-T); (2) PRP-T reconstituted with DTP and administered concomitantly with an oral poliovirus vaccine (DTP//PRP-T+OPV); and (3) PRP-T administered concomitantly with DTP at a different injection site and OPV (DTP+PRP-T+OPV). Vaccines were given at 2, 4, and 6 months of age. A total of 252 infants were enrolled, and randomly assigned to one of the three vaccination groups (84 infants in each group); 241 infants were followed until the end of the study. Antibody production against PRP, diphtheria, tetanus and pertussis antigens was satisfactory for each vaccination scheme used. A good response to Hib vaccine was elicited in each group, and 3 months after the third vaccine dose, at least 97% of children in each group had levels of PRP antibody considered to be seroprotective (>0.15 microg/ml), and over 90% of children in each group had levels over 1. 0 microg/ml. The solicited local and systemic adverse events following vaccination were mild in all groups and resolved within 4 days without medical intervention. With the exception of fever, which was more common after the second dose in children who received DTP-IPV//PRP-T, local and systemic reactions did not differ between the vaccination groups. Due to the practical advantages of combined vaccines, their use in routine immunization programs in developing countries is highly desirable. Our results show that Hib conjugate vaccine can be included in routine immunization programs that include either OPV or IPV with satisfactory immunogenicity and safety profiles. This flexible approach should facilitate the inclusion of the Hib conjugate vaccine in routine immunization programs on a world-wide scale.     

Pertussis--United States, 1997-2000

Pertussis was a major cause of morbidity and mortality among infants and children in the United States during the prevaccine era (i.e., before the mid-1940s). Following the introduction and widespread use of whole-cell pertussis vaccine combined with diphtheria and tetanus toxoids (DTP) among infants and children in the late 1940s, the incidence of reported pertussis declined to a historic low of 1,010 cases in 1976 (Figure 1). However, since the early 1980s, reported pertussis incidence has increased cyclically with peaks occurring every 3-4 years. In 1996, less reactogenic acellular pertussis vaccines (DTaP) were licensed and recommended for routine use among infants. This report summarizes national surveillance data for pertussis during 1997-2000 and assesses the effectiveness of pertussis vaccination in the United States during this period. The findings indicate that pertussis incidence continues to increase in infants too young to receive 3 doses of pertussis-containing vaccine and in adolescents and adults. Prevention efforts should be directed at maintaining high vaccination rates and managing pertussis cases and outbreaks.     

Effect of food coupon incentives on timely completion of DTP immunization series in children from a low-income area in Karachi,Pakistan: A longitudinal intervention study

This study introduced food/medicine vouchers as an incentive to mothers of infants visiting Expanded Program on Immunization (EPI) centers in a low socio-economic area. The timely completion of diphtheria, tetanus and pertussis vaccines combined (DTP) series immunization rates between intervention and control cohorts were compared. The DTP up-to-date immunization coverage at 18 weeks of age increased two-fold (RR 2.20, 95% CI: 1.95–2.48, p < 0.001) in the incentive cohort compared to the no-incentive cohort. While increasing immunization coverage is a complex structural and behavioral process, food/medicine coupon may improve routine immunization coverage in developing countries.     

Seroprotection against tetanus in southern Vietnam

BackgroundOngoing tetanus cases and sporadic outbreaks of vaccine-preventable diseases associated with routine vaccination programmes remain problems in many low and middle-income countries, including Vietnam. With no human-to-human transmission or natural immunity, tetanus antibody levels indicate both individual risk of tetanus and gaps in vaccination programmes.MethodsTo investigate gaps in immunity to tetanus in Vietnam, a country with a historically high level of tetanus vaccination coverage, tetanus antibodies were measure by ELISA from samples selected from a long-term serum bank, established for the purposes of general-population seroepidemiological investigations in southern Vietnam. Samples were selected from 10 provinces, focussing on age-groups targeted by national vaccination programmes for infants and pregnant women (Expanded Programme on Immunization, EPI, and Maternal and Neonatal Tetanus, MNT).ResultsAntibodies were measured from a total of 3864 samples. Highest tetanus antibody concentrations occurred in children under 4 years old, over 90 % of whom had protective levels. Approximately 70 % of children aged 7–12 years had protective antibody concentrations although there was variation among provinces. For infants and children, there were no significant differences in tetanus protection between males and females, but for adults aged 20–35 years, in five of the ten provinces surveyed, protection against tetanus was higher in females (p < 0.05) who are eligible for booster doses under the MNT programme. In seven of ten provinces, antibody concentrations were inversely related to age (p < 0.01) and protection of older individuals was generally low.ConclusionWidespread immunity to tetanus toxoid is seen in infants and young children consistent with the high coverage rates reported for diptheria tetanus toxoid and pertussis (DTP) in Vietnam. However, the lower antibody concentrations seen in older children and men suggest reduced immunity to tetanus in populations not targeted by EPI and MNT programmes.     

Pertussis--United States, 2001-2003

Pertussis is a highly contagious, vaccine-preventable bacterial illness characterized by paroxysmal cough, posttussive vomiting, and inspiratory whoop. Pertussis also can occur as a mild or moderate cough illness in persons who are partially immune. In the United States, most hospitalizations and nearly all deaths from pertussis are reported in infants aged <6 months, but substantial morbidity does occur in other age groups. Infant/childhood vaccination has contributed to a reduction of more than 90% in pertussis-related morbidity and mortality since the early 1940s in the United States. Estimates of childhood vaccination coverage with > or =3 doses of pertussis-containing vaccine have exceeded 90% since 1994; however, reported pertussis cases increased from a historic low of 1,010 in 1976 to 11,647 cases in 2003. A substantial increase in reported cases has occurred among adolescents, who become susceptible to pertussis approximately 6-10 years after childhood vaccination. Recently, booster vaccines for adolescents and adults combining pertussis antigens with tetanus and diphtheria toxoids (Tdap) were approved by the Food and Drug Administration (FDA). On June 30, 2005, the Advisory Committee on Immunization Practices (ACIP) recommended Tdap for all persons aged 11-18 years. This report summarizes national surveillance data on pertussis reported to CDC during 2001-2003 and focuses on pertussis reported among persons aged 10-19 years before implementation of national recommendations for adolescent pertussis vaccination.     

Child vaccination in sub-Saharan Africa: Increasing coverage addresses inequalities

BackgroundVaccines have substantially contributed to reducing morbidity and mortality among children, but inequality in coverage continues to persist. In this study, we aimed to examine inequalities in child vaccination coverage in sub-Saharan Africa.MethodsWe analysed Demographic and Health Survey data in 25 sub-Saharan African countries. We defined full vaccination coverage as a child who received one dose of bacille Calmette-Guérin vaccine (BCG), three doses of diphtheria, pertussis, and tetanus vaccine (DTP 3), three oral polio vaccine doses (OPV 3), and one dose of measles vaccine. We used the concentration index (CCI) to measure wealth-related inequality in full vaccination, incomplete vaccination, and zero-dose children within and between countries. We fitted a multilevel regression model to identify predictors of inequality in receipts of full vaccination.ResultsOverall, 56.5% (95% CI: 55.7% to 57.3%) of children received full vaccination, 35.1% (34.4% to 35.7%) had incomplete vaccination, while 8.4% (95% CI: 8.0% to 8.8%) of children remained unvaccinated. Full vaccination coverage across the 25 sub-Saharan African countries ranged from 24% in Guinea to 93% in Rwanda. We found pro-rich inequality in full vaccination coverage in 23 countries, except for Gambia and Namibia, where we found pro-poor vaccination coverage. Countries with lower vaccination coverage had higher inequalities suggesting pro-rich coverage, while inequality in unvaccinated children was disproportionately concentrated among disadvantaged subgroups. Four or more antenatal care contracts, childbirth at health facility, improved maternal education, higher household wealth, and frequently listening to the radio increased vaccine uptake.ConclusionsContinued efforts to improve access to vaccination services are required in sub-Saharan Africa. Improving vaccination coverage and reducing inequalities requires enhancing access to quality services that are accessible, affordable, and acceptable to all. Vaccination programs should target critical social determinants of health and address barriers to better maternal health-seeking behaviour.     

Immunogenicity of a combined diphtheria-tetanus-acellular pertussis vaccine in adults

Two clinical studies were undertaken to evaluate the immunogenicity of an adult-type dTpa booster vaccine (Boostrix by GlaxoSmithKline Biologicals). Blood samples taken prior to vaccination showed that 24.4 and 13.0% of subjects were seronegative for diphtheria and tetanus antibodies, respectively. Moreover, about one-third of the vaccinees had no detectable levels of antibodies to pertussis toxoid (PT) or pertactin (PRN). One month post-vaccination, more than 93% of all individuals, regardless of age or type of vaccine received, had seroprotective antibody levels for diphtheria and tetanus (> or = 0.1IU/ml). In those individuals vaccinated with the adult-type dTpa vaccine (Boostrix), more than 98% were found to be seropositive for antibodies to all three pertussis antigens (PT, filamentous haemogluttin (FHA), and PRN). These data suggest that immunity to diphtheria, tetanus and pertussis (DTP) in adults wanes and that booster vaccination with an adult-type combined dTpa vaccine would boost the serological response to diphtheria antitoxin, tetanus antitoxin and antibodies to Bordetella pertussis PT, FHA and PRN.     

Progress in global measles control and mortality reduction, 2000-2006

The World Health Organization (WHO) and United Nations Children's Fund (UNICEF) comprehensive strategy for measles mortality reduction is focused on 47 priority countries. Components include 1) achieving and maintaining high coverage (>90%) with the first dose of measles vaccine by age 12 months in every district of each priority country through routine immunization services; 2) ensuring that all children receive a second opportunity for measles vaccination; 3) maintaining effective case-based surveillance and monitoring of vaccination coverage; and 4) providing appropriate clinical management, including vitamin A supplementation. In 2005, the World Health Assembly set a goal for global measles control as part of the Global Immunization Vision and Strategy (GIVS): a 90% reduction in measles mortality by 2010, compared with 2000 levels. In January 2007, WHO/UNICEF reported that implementation of measles mortality reduction strategies had reduced measles mortality by 60%, from an estimated 873,000 deaths in 1999 to 345,000 deaths in 2005. This reduction exceeded the goal of 50% measles mortality reduction by 2005 (compared with 1999 levels) that had been set in 2002. This report updates previous reports by detailing 1) measles mortality reduction activities implemented during 2006 and 2) the impact of activities since 2000 on the global burden of measles and progress toward the GIVS mortality reduction goal for 2010.