The Advisory Committee on Immunization Practices (ACIP) recommends that adolescents aged 11-12 years routinely receive vaccines to prevent diseases, including human papillomavirus (HPV)-associated cancers, pertussis, and meningococcal disease (1). To assess vaccination coverage among adolescents in the United States, CDC analyzed data collected regarding 21,875 adolescents through the 2015 National Immunization Survey-Teen (NIS-Teen).* During 2014-2015, coverage among adolescents aged 13-17 years increased for each HPV vaccine dose among males, including ≥1 HPV vaccine dose (from 41.7% to 49.8%), and increased modestly for ≥1 HPV vaccine dose among females (from 60.0% to 62.8%) and ≥1 quadrivalent meningococcal conjugate vaccine (MenACWY) dose (from 79.3% to 81.3%). Coverage with ≥1 HPV vaccine dose was higher among adolescents living in households below the poverty level, compared with adolescents in households at or above the poverty level.(†) HPV vaccination coverage (≥1, ≥2, or ≥3 doses) increased in 28 states/local areas among males and in seven states among females. Despite limited progress, HPV vaccination coverage remained lower than MenACWY and tetanus, diphtheria, and acellular pertussis vaccine (Tdap) coverage, indicating continued missed opportunities for HPV-associated cancer prevention.
The Advisory Committee on Immunization Practices (ACIP) recommends that adolescents routinely receive tetanus, diphtheria, and acellular pertussis vaccine (Tdap), meningococcal conjugate vaccine (MenACWY), and human papillomavirus (HPV) vaccine (1) at age 11-12 years. ACIP also recommends catch-up vaccination with hepatitis B vaccine, measles, mumps, and rubella (MMR) vaccine, and varicella vaccine for adolescents who are not up to date with childhood vaccinations. ACIP recommends a booster dose of MenACWY at age 16 years (1). In December 2016, ACIP updated HPV vaccine recommendations to include a 2-dose schedule for immunocompetent adolescents initiating the vaccination series before their 15th birthday (2). To estimate adolescent vaccination coverage in the United States, CDC analyzed data from the 2016 National Immunization Survey-Teen (NIS-Teen) for 20,475 adolescents aged 13-17 years.* During 2015-2016, coverage increased for ≥1 dose of Tdap (from 86.4% to 88.0%) and for each HPV vaccine dose (from 56.1% to 60.4% for ≥1 dose). Among adolescents aged 17 years, coverage with ≥2 doses of MenACWY increased from 33.3% to 39.1%. In 2016, 43.4% of adolescents (49.5% of females; 37.5% of males) were up to date with the HPV vaccination series, applying the updated HPV vaccine recommendations retrospectively.(†) Coverage with ≥1 HPV vaccine dose varied by metropolitan statistical area (MSA) status and was lowest (50.4%) among adolescents living in non-MSA areas and highest (65.9%) among those living in MSA central cities.(§) Adolescent vaccination coverage continues to improve overall; however, substantial opportunities exist to further increase HPV-associated cancer prevention.
Acellular vaccines against Bordetella pertussis were introduced in Australia in 1997. By 2000, these vaccines had replaced whole-cell vaccines. During 2008-2012, a large outbreak of pertussis occurred. During this period, 30% (96/320) of B. pertussis isolates did not express the vaccine antigen pertactin (Prn). Multiple mechanisms of Prn inactivation were documented, including IS481 and IS1002 disruptions, a variation within a homopolymeric tract, and deletion of the prn gene. The mechanism of lack of expression of Prn in 16 (17%) isolates could not be determined at the sequence level. These findings suggest that B. pertussis not expressing Prn arose independently multiple times since 2008, rather than by expansion of a single Prn-negative clone. All but 1 isolate had ptxA1, prn2, and ptxP3, the alleles representative of currently circulating strains in Australia. This pattern is consistent with continuing evolution of B. pertussis in response to vaccine selection pressure.
Sustained high coverage with recommended vaccinations among children has kept many vaccine-preventable diseases at low levels in the United States (1). To assess coverage with vaccinations recommended for children by age 2 years in the United States (2), CDC analyzed data collected by the 2015 National Immunization Survey (NIS) for children aged 19-35 months (born January 2012-May 2014). Overall, coverage did not change during 2014-2015. Coverage in 2015 was highest for ≥3 doses of poliovirus vaccine (93.7%), ≥3 doses of hepatitis B vaccine (HepB) (92.6%), ≥1 dose of measles, mumps, and rubella vaccine (MMR) (91.9%), and ≥1 dose of varicella vaccine (91.8%). The data were also examined for potential vaccination coverage differences by race/ethnicity, poverty status, and urbanicity. Although disparities were noted for each of these factors, the most striking differences were seen for poverty status. Children living below the federal poverty level* had lower coverage with most of the vaccinations assessed compared with children living at or above the poverty level; the largest disparities were for rotavirus vaccine (66.8% versus 76.8%), ≥4 doses of pneumococcal conjugate vaccine (PCV) (78.9% versus 87.2%), the full series of Haemophilus influenzae type b vaccine (Hib) (78.1% versus 85.5%), and ≥4 doses of diphtheria, tetanus, and acellular pertussis vaccine (DTaP) (80.2% versus 87.1%). Although coverage was high in some groups, opportunities exist to continue to address disparities. Implementation of evidence-based interventions, including strategies to enhance access to vaccination services and systems strategies that can reduce missed opportunities, has the potential to increase vaccination coverage for children living below the poverty level and in rural areas (3).
Pertussis in adults and adolescents could be reduced by replacing traditional tetanus and diphtheria (Td) boosters with reduced-antigen-content diphtheria-tetanus-acellular pertussis (dTpa) vaccines. This study evaluated the administration of dTpa-IPV (dTpa-inactivated poliovirus) in adults ten years after they received a booster dose of either dTpa-IPV, dTpa+IPV or Td-IPV in trial NCT01277705.
The introduction of vaccination worldwide dramatically reduced the incidence of pathogenic bacterial and viral diseases. Despite the highly successful vaccination strategies, the number of cases among vaccine preventable diseases has increased in the last decade and several of those diseases are still endemic in different countries. Here we discuss some epidemiological aspects and possible arguments that may explain why ancient diseases such as, measles, polio, pertussis, diphtheria and tuberculosis are still with us.
- CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne
- Published over 3 years ago
A resurgence of pertussis cases among both vaccinated and unvaccinated people raises questions about vaccine effectiveness over time. Our objective was to study the effectiveness of the pertussis vaccine and characterize the effect of waning immunity and whole-cell vaccine priming.
The recent increase in whooping cough incidence (primary caused by Bordetella pertussis) presents a challenge to both public health practitioners and scientists trying to understand the mechanisms behind its resurgence. Three main hypotheses have been proposed to explain the resurgence: 1) waning of protective immunity from vaccination or natural infection over time, 2) evolution of B. pertussis to escape protective immunity, and 3) low vaccine coverage. Recent studies have suggested a fourth mechanism: asymptomatic transmission from individuals vaccinated with the currently used acellular B. pertussis vaccines.
State and local school vaccination requirements help protect students and communities against vaccine-preventable diseases (1). CDC reports vaccination coverage and exemption data for children attending kindergarten (kindergartners) collected by federally funded immunization programs in the United States.* The typical age range for kindergartners is 4-6 years. Although vaccination requirements vary by state (the District of Columbia [DC] is counted as a state in this report.), the Advisory Committee on Immunization Practices recommends that children in this age range have received, among other vaccinations, 5 doses of diphtheria, tetanus, and acellular pertussis vaccine (DTaP), 2 doses of measles, mumps, and rubella vaccine (MMR), and 2 doses of varicella vaccine (2). This report summarizes 2016-17 school year MMR, DTaP, and varicella vaccination coverage reported by immunization programs in 49 states, exemptions in 50 states, and kindergartners provisionally enrolled or within a grace period in 27 states. Median vaccination coverage(†) was 94.5% for the state-required number of doses of DTaP; 94.0% for 2 doses of MMR; and 93.8% for 2 doses of varicella vaccine. The median percentage of kindergartners with an exemption from at least one vaccine(§) was 2.0%, similar to 2015-16 (1.9%). Median grace period and provisional enrollment was 2.0%. Vaccination coverage remains consistently high and exemptions low at state and national levels. Local-level vaccination coverage data provide opportunities for immunization programs to identify schools, districts, counties, or regions susceptible to vaccine-preventable diseases and for schools to address undervaccination through implementation of existing state and local vaccination policies (1) to protect communities through increased coverage.
Vaccination is the most effective intervention to reduce morbidity and mortality from vaccine-preventable diseases in young children (1). Data from the 2016 National Immunization Survey-Child (NIS-Child) were used to assess coverage with recommended vaccines (2) among children aged 19-35 months in the United States. Coverage remained ≥90% for ≥3 doses of poliovirus vaccine (91.9%), ≥1 dose of measles, mumps, and rubella vaccine (MMR) (91.1%), ≥1 dose of varicella vaccine (90.6%), and ≥3 doses of hepatitis B vaccine (HepB) (90.5%). Coverage in 2016 was approximately 1-2 percentage points lower than in 2015 for ≥3 doses of diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP), ≥3 doses of poliovirus vaccine, the primary Haemophilus influenzae type b (Hib) series, ≥3 HepB doses, and ≥3 and ≥4 doses of pneumococcal conjugate vaccine (PCV), with no changes for other vaccines. More direct evaluation of trends by month and year of birth (3) found no change in coverage by age 2 years among children included in combined data from the 2015 and 2016 NIS-Child (born January 2012 through January 2015). The observed decreases in annual estimates might result from random differences in vaccination coverage by age 19 months between children sampled in 2016 and those sampled in 2015, among those birth cohorts eligible to be sampled in both survey years. For most vaccines, 2016 coverage was lower among non-Hispanic black* (black) children than among non-Hispanic white (white) children, and for children living below the federal poverty level(†) compared with those living at or above the poverty level. Vaccination coverage was generally lower among children insured by Medicaid (2.5-12.0 percentage points), and was much lower among uninsured children (12.4-24.9 percentage points), than among children with private insurance. The Vaccines for Children(§) (VFC) program was designed to increase access to vaccines among children who might not otherwise be vaccinated because of inability to pay. Greater awareness and facilitating use of VFC might be helpful in reducing these disparities. Efforts should also be focused on minimizing breaks in continuity of health insurance and eliminating missed opportunities to vaccinate children during visits to health care providers. Despite the observed disparities and small changes in coverage from 2015, vaccination coverage among children aged 19-35 months remained high and stable in 2016.