Mary Mason McCauley

Standards for adult immunization practices

Since the Standards for Adult Immunization Practices were first published in 1990, healthcare researchers and providers have learned important lessons on how to better achieve and maintain high vaccination rates in adults. The success rate of childhood immunization far exceeds the success rate of adult immunization. Thus, information and practices that will produce higher success rates for adult vaccination are crucial, resulting in overall societal cost savings and substantial reductions in hospitalizations and deaths. The Standards, which were developed to encourage the best immunization practices, represent the collective efforts of more than 100 people from more than 60 organizations. The revised Standards are more comprehensive than the 1990 Standards and focus on the accessibility and availability of vaccines, proper assessment of patient vaccination status, opportunities for patient education, correct procedures for administering vaccines, implementation of strategies to improve vaccination rates, and partnerships with the community to reach target patient populations. The revised Standards are recommended for use by all healthcare professionals and all public and private sector organizations that provide immunizations for adults. All who are involved in adult immunization should strive to follow the Standards in order to create the same level of success achieved by childhood vaccination programs and to meet the Healthy People 2010 goals.

Timeliness of childhood immunizations : A state-specific analysis

OBJECTIVE We examined the timeliness of vaccine administration among children aged 24 to 35 months for each state of the United States and the District of Columbia. METHODS We analyzed the timeliness of vaccinations in the 2000-2002 National Immunization Survey. We used a modified Bonferroni adjustment to compare a reference state with all other states. RESULTS Receipt of all vaccinations as recommended ranged from 2% (Mississippi) to 26% (Massachusetts), with western states having less timeliness than eastern states. CONCLUSIONS Vaccination coverage measures usually focus on the number of vaccinations accumulated by specified ages. Our analysis of timeliness of administration shows that children rarely receive all vaccinations as recommended. State health departments can use timeliness of vaccinations along with other measures to determine childrens susceptibility to vaccine-preventable diseases and to evaluate the quality of vaccination programs. States can use the modified Bonferroni comparison to appropriately compare their results with other states.

Adolescent Immunizations and Other Clinical Preventive Services: A Needle and a Hook?

Advances in technology have led to development of new vaccines for adolescents, but these vaccines will be added to a crowded schedule of recommended adolescent clinical preventive services. We reviewed adolescent clinical preventive health care guidelines and patterns of adolescent clinical preventive service delivery and assessed how new adolescent vaccines might affect health care visits and the delivery of other clinical preventive services. Our analysis suggests that new adolescent immunization recommendations are likely to improve adolescent health, both as a “needle” and a “hook.” As a needle, the immunization will enhance an adolescents health by preventing vaccine-preventable diseases during adolescence and adulthood. It also will likely be a hook to bring adolescents (and their parents) into the clinic for adolescent health care visits, during which other clinical preventive services can be provided. We also speculate that new adolescent immunization recommendations might increase the proportion and quality of other clinical preventive services delivered during health care visits. The factor most likely to diminish the positive influence of immunizations on delivery of other clinical preventive services is the additional visit time required for vaccine counseling and administration. Immunizations may “crowd out” delivery of other clinical preventive services during visits or reduce the quality of the clinical preventive service delivery. Complementary strategies to mitigate these effects might include prioritizing clinical preventive services with a strong evidence base for effectiveness, spreading clinical preventive services out over several visits, and withholding selected clinical preventive services during a visit if the prevention activity is effectively covered at the community level. Studies are needed to evaluate the effect of new immunizations on adolescent preventive health care visits, delivery of clinical preventive services, and health outcomes.

An Economic Analysis of the Current Universal 2-dose measles-mumps-rubella Vaccination Program in the United States

To evaluate the economic impact of the current 2-dose measles-mumps-rubella (MMR) vaccination program in the United States, a decision tree-based analysis was conducted with population-based vaccination coverage and disease incidence data. All costs were estimated for a hypothetical US birth cohort of 3803295 infants born in 2001. The 2-dose MMR vaccination program was cost-saving from both the direct cost and societal perspectives compared with the absence of MMR vaccination, with net savings (net present value) from the direct cost and societal perspectives of US dollars 3.5 billion and US dollars 7.6 billion, respectively. The direct and societal benefit-cost ratios for the MMR vaccination program were 14.2 and 26.0. Analysis of the incremental benefit-cost of the second dose showed that direct and societal benefit-cost ratios were 0.31 and 0.49, respectively. Varying the proportion of vaccines purchased and administered in the public versus the private sector had little effect on the results. From both perspectives under even the most conservative assumptions, the national 2-dose MMR vaccination program is highly cost-beneficial and results in substantial cost savings.

Legal basis of consent for health care and vaccination for adolescents.

State law is generally the controlling authority for whether parental consent is required or minors may consent for their own health care, including vaccination. At the federal level, no vaccination consent law exists; however, federal law requires that vaccine information statements be given to the parent or another person who is qualified under state law to consent to vaccination of a minor. All states allow minors to consent for their own health care in some circumstances on the basis of either (1) their status (eg, age, emancipation, marriage) or (2) the kind of health care services they are seeking (eg, family planning services, treatment of sexually transmitted disease). In each state, a specific analysis of laws will be required to determine the circumstances under which a minor can consent for vaccination.

Predictors of age-appropriate receipt of DTaP Dose 4

BACKGROUND In the United States, the national childhood immunization schedule calls for children to receive four doses of DTaP (diphtheria and tetanus toxoids and acellular pertussis) vaccine administered at 2, 4, 6, and 15 to 18 months. Dose 4 of DTaP is among the most frequently missed vaccines for children who are not adequately immunized. METHODS Using the 2001 National Immunization Survey, the effect of the timeliness of the first three DTaP doses was assessed on completion of the four-dose series by age 24 months and on time by age 12 to 18 months. RESULTS Missing Dose 4 was more prevalent among children who received Dose 3 late (but <16 months) than among children who received Dose 3 on time (24% vs 10%). Similarly, receiving Dose 4 late (or not at all) was more prevalent among children who received Dose 3 late (but <9 months) (39% vs 22%). An invalid Dose 4 was administered to 4.6% of those with Dose 3 late but before 9 months and to 10.6% of those with no Dose 3 before 9 months, compared to 1.2% of those with Dose 3 on time. CONCLUSIONS Physicians and staff can identify children at risk for missing the fourth DTaP dose or receiving it late by assessing timeliness of receipt of DTaP Dose 3 and implementing steps to ensure that at-risk children receive Dose 4 as recommended.

Projected Cost-effectiveness of New Vaccines for Adolescents in the United States

BACKGROUND. Economic assessments that guide policy making on immunizations are becoming increasingly important in light of new and anticipated vaccines for adolescents. However, important considerations that limit the utility of these assessments, such as the diversity of approaches used, are often overlooked and should be better understood. OBJECTIVE. Our goal was to examine economic studies of adolescent vaccines and compare cost-effectiveness outcomes among studies on a particular vaccine, across adolescent vaccines, and between new adolescent vaccines versus vaccines that are recommended for young children. METHODS. A systematic review of economic studies on immunizations for adolescents was conducted. Studies were identified by searching the Medline, Embase, and EconLit databases. Each study was reviewed for appropriateness of model design, baseline setup, sensitivity analyses, and input variables (ie, epidemiologic, clinical, cost, and quality-of-life impact). For comparison, the cost-effectiveness outcomes reported in key studies on vaccines for younger children were selected. RESULTS. Vaccines for healthy adolescents were consistently found to be more costly than the health care or societal cost savings they produced and, in general, were less cost-effective than vaccines for younger children. Among the new vaccines, pertussis and human papillomavirus vaccines were more cost-effective than meningococcal vaccines. Including herd-immunity benefits in studies significantly improved the cost-effectiveness estimates for new vaccines. Differences in measurements or assumptions limited further comparisons. CONCLUSION. Although using the new adolescent vaccines is unlikely to be cost-saving, vaccination programs will result in sizable health benefits.

Evaluation of Targeted Influenza Vaccination Strategies via Population Modeling

Background Because they can generate comparable predictions, mathematical models are ideal tools for evaluating alternative drug or vaccine allocation strategies. To remain credible, however, results must be consistent. Authors of a recent assessment of possible influenza vaccination strategies conclude that older children, adolescents, and young adults are the optimal targets, no matter the objective, and argue for vaccinating them. Authors of two earlier studies concluded, respectively, that optimal targets depend on objectives and cautioned against changing policy. Which should we believe? Methods and Findings In matrices whose elements are contacts between persons by age, the main diagonal always predominates, reflecting contacts between contemporaries. Indirect effects (e.g., impacts of vaccinating one group on morbidity or mortality in others) result from off-diagonal elements. Mixing matrices based on periods in proximity with others have greater sub- and super-diagonals, reflecting contacts between parents and children, and other off-diagonal elements (reflecting, e.g., age-independent contacts among co-workers), than those based on face-to-face conversations. To assess the impact of targeted vaccination, we used a time-usage studys mixing matrix and allowed vaccine efficacy to vary with age. And we derived mortality rates either by dividing observed deaths attributed to pneumonia and influenza by average annual cases from a demographically-realistic SEIRS model or by multiplying those rates by ratios of (versus adding to them differences between) pandemic and pre-pandemic mortalities. Conclusions In our simulations, vaccinating older children, adolescents, and young adults averts the most cases, but vaccinating either younger children and older adults or young adults averts the most deaths, depending on the age distribution of mortality. These results are consistent with those of the earlier studies.

Has Surveillance Been Adequate to Detect Endemic Measles in the United States

Evidence that endemic measles has been eliminated in the United States rests on the performance of the surveillance system. Information from national surveillance data allows us to evaluate the adequacy of national surveillance to detect the circulation of endemic measles. Sources of data include measles report dates, international importation status, and the size of chains of measles transmission. The proportion of chains of measles transmission that can be epidemiologically linked to international importations is high (62%), as would be expected if measles is no longer circulating; the number of imported cases, although lower than estimated expected values, is within a reasonable range of expectation. National surveillance detects even small outbreaks, so larger outbreaks that are the marker for endemic transmission would almost certainly be detected. Few unreported cases of measles are detected when health departments conduct careful investigations in response to reports of an index case. Surveillance appears to be adequate to support the contention that measles is no longer endemic in the United States.

The First Oral Rotavirus Vaccine, 1998-1999: Estimates of Uptake from the National Immunization Survey

Objective. On August 31, 1998, the rhesus-human reassortant rotavirus vaccine (RRV-TV) was licensed for use in the U.S. During the next nine months, 15 cases of intussusception were reported among infants who received the vaccine. Case-control and cohort studies showed a significantly increased risk of developing intussusception within one week of receiving the vaccine; subsequent ecologic studies did not. In this study, the authors used data on RRV-TV vaccination rates from the National Immunization Survey (NIS) to estimate state and national RRV-TV uptake rates and factors associated with receiving RRV-TV. These estimates are a key component in evaluating published ecologic studies designed to investigate the relationship between receipt of the vaccine and intussusception. Methods. The authors analyzed NIS data for children ages 19 to 35 months who were eligible to receive RRV-TV between September 1998 and July 1999. The authors estimated vaccine coverage and the number of doses administered by state, NIS sampling quarter, and birth cohort, and analyzed demographic and socioeconomic variables to evaluate their relationship with receiving RRV-TV. Results. It was estimated that approximately 1 million doses of RRV-TV were administered to 504,585 (±61,854) children, 13.4% (±1.6%) of children who were eligible. The estimated number of doses administered and the vaccination coverage rate varied greatly from state to state. Children living in households with higher socioeconomic conditions were more likely to receive the vaccine. Conclusion. Ecologic studies had a limited ability to detect a significant increase in the population incidence rate of intussusception that could be attributed to RRV-TV because populations in these studies consisted primarily of children who did not receive the vaccine. The example from RRV-TV demonstrates some of the challenges of assessing the magnitude of the association between a vaccine and an uncommon or rare adverse event.