Student vaccination requirements of U.S. health professional schools: a survey.

BACKGROUND: Unvaccinated health care personnel are at increased risk for transmitting vaccine-preventable diseases to their patients. The Advisory Committee on Immunization Practices (ACIP) recommends that health care personnel, including students, receive measles, mumps, rubella, hepatitis B, varicella, influenza, and pertussis vaccines. Prematriculation vaccination requirements of health professional schools represent an early opportunity to ensure that health care personnel receive recommended vaccines. OBJECTIVE: To examine prematriculation vaccination requirements and related policies at selected health professional schools in the United States and compare requirements with current ACIP recommendations. DESIGN: Cross-sectional study using an Internet-based survey. SETTING: Medical and baccalaureate nursing schools in the United States and its territories. PARTICIPANTS: Deans of accredited medical schools granting MD (n = 130) and DO (n = 26) degrees and of baccalaureate nursing programs (n = 603). MEASUREMENTS: Proportion of MD-granting and DO-granting schools and baccalaureate nursing programs that require that entering students receive vaccines recommended by the ACIP for health care personnel. RESULTS: 563 schools (75%) responded. More than 90% of all school types required measles, mumps, rubella, and hepatitis B vaccines for entering students; varicella vaccination also was commonly required. Tetanus, diphtheria, and acellular pertussis vaccination was required by 66%, 70%, and 75% of nursing, MD-granting, and DO-granting schools, respectively. Nursing and DO-granting schools (31% and 45%, respectively) were less likely than MD-granting schools (78%) to offer students influenza vaccines free of charge. LIMITATIONS: Estimates were conservative, because schools that reported that they did not require proof of immunity for a given vaccine were considered not to require that vaccine. Estimates also were restricted to schools that train physicians and nurses. CONCLUSION: The majority of schools now require most ACIP-recommended vaccines for students. Medical and nursing schools should adopt policies on student vaccination and serologic testing that conform to ACIP recommendations and should encourage annual influenza vaccination by offering influenza vaccination to students at no cost. PRIMARY FUNDING SOURCE: None.

Introduction: vaccination against smallpox in the posteradication era.

The following introduction describes the context in which the national smallpox vaccination program was implemented and highlights the significance of the key policy, programmatic, or scientific challenges, observations, and lessons learned that are presented in the articles that follow within this supplement to Clinical Infectious Diseases. Although the execution of this national program posed multiple complex and varied challenges, the focus of this supplement is on vaccine-associated adverse events and vaccine safety.

Economics of cardiac adverse events after smallpox vaccination: lessons from the 2003 US Vaccination Program.

Of >39,000 civilian public health responders vaccinated against smallpox in 2003, 203 reported cardiovascular adverse events (CAEs). An association exists between the US vaccinia strain and myocarditis and/or pericarditis ("myo/pericarditis" [MP]). Other associations are inconclusive. We used surveillance and follow-up survey data of CAE case patients to estimate the resources used during the 2003 smallpox vaccination program and used a probabilistic model to estimate the potential costs of CAEs in a mass vaccination campaign. For every million adult vaccinees, 3001 CAEs (including 351 MP cases) would occur, with >92% in revaccinees. CAEs would require a median of 5934 outpatient visits, 1786 emergency department visits, 533 days in general wards, 132 days in intensive care units, 5484 cardiac enzymes tests, 3504 electrocardiograms, 3049 chemistry tests, 2828 complete blood counts, and 1444 transthoracic echocardiograms, among other procedures. CAEs would reduce productivity (15,969 work days lost) and cost $11 per vaccinee. In a mass vaccination campaign, the care of a sizable number of CAEs would be resource intensive.

A review of the smallpox vaccine adverse events active surveillance system.

In response to concern about smallpox possibly being used as a biological weapon, the President of the United States launched the National Smallpox Pre-Event Vaccination Program on 13 December 2002. Given safety concerns, identifying potentially serious adverse events (SAEs) was an essential tool of the program. To monitor for SAEs, both enhanced passive surveillance and active surveillance systems were used. The enhanced passive system was built, in part, on the existing Vaccine Adverse Event Reporting System; the active system was implemented 24 January 2003. During January 2003-May 2005, the active system detected only 1 SAE in addition to those reported through the enhanced passive system. Furthermore, the active system was not universally used by states. With the enhancements to passive surveillance, the performance of enhanced passive surveillance was comparable to that of active surveillance. However, an active surveillance system may be important when there is no enhanced passive surveillance system available.

Follow-up of cardiovascular adverse events after smallpox vaccination among civilians in the United States, 2003.

Limited information exists regarding intermediate or long-term consequences of cardiac adverse events (CAEs) after smallpox vaccination. We conducted follow up at 5-12 months after vaccination of 203 US civilian vaccinees who reported a possible CAE. Among 31 of the 33 with confirmed CAEs, at least 1 health-related quality-of-life change persisted for approximately 48%; approximately 87% missed work (average, 11.5 days). Among 168 of the 170 case patients with other reported cardiovascular conditions, at least 1 health-related quality-of-life change persisted for approximately 40%; almost 49% missed work (average, 10.2 days). Almost all vaccinees with possible CAEs were working the same number of hours at follow-up compared with before vaccination. Although intermediate-term consequences among possible postvaccination CAEs were not considered serious, lost days of work and a decline in health-related quality of life at the time of follow-up were common, resulting in personal economic and quality-of-life burden.

Ischemic cardiac events during the Department of Health and Human Services Smallpox Vaccination Program, 2003.

Ten ischemic cardiac events (ICEs) were reported among 37,901 initial US Department of Health and Human Services (DHHS) smallpox vaccinees. Symptoms developed a median of 10 days after vaccination (range, 0-28 days). The median age of case patients was 56 years (range, 42-65 years), and 60% were male. Seven (70%) of the case patients had >/=3 cardiac risk factors or probable coronary artery disease before vaccination. Two women, 55 and 57 years of age, experienced acute myocardial infarction and fatal cardiac arrests. Background rates of ICEs during a 3-week period for civilian populations that were age and sex matched to DHHS vaccinees were estimated. The observed number of myocardial infarctions exceeded estimated expectations (5 vs. 2) but remained within the 95% predictive interval (PI) (0.6-5.4). New onset angina was observed significantly less frequently than estimated expectations (1 vs. 10; 95% PI, 3.5-15.7). After persons with >/=3 cardiac risk factors or known heart disease were deferred from vaccination, no ICEs were reported among an additional 6638 vaccinees.

Myocarditis, pericarditis, and dilated cardiomyopathy after smallpox vaccination among civilians in the United States, January-October 2003.

Myocarditis was reported after smallpox vaccination in Europe and Australia, but no association had been reported with the US vaccine. We conducted surveillance to describe and determine the frequency of myocarditis and/or pericarditis (myo/pericarditis) among civilians vaccinated during the US smallpox vaccination program between January and October 2003. We developed surveillance case definitions for myocarditis, pericarditis, and dilated cardiomyopathy after smallpox vaccination. We identified 21 myo/pericarditis cases among 37,901 vaccinees (5.5 per 10,000); 18 (86%) were revacinees, 14 (67%) were women, and the median age was 48 years (range, 25-70 years). The median time from vaccination to onset of symptoms was 11 days (range, 2-42 days). Myo/pericarditis severity was mild, with no fatalities, although 9 patients (43%) were hospitalized. Three additional vaccinees were found to have dilated cardiomyopathy, recognized within 3 months after vaccination. We describe an association between smallpox vaccination, using the US vaccinia strain, and myo/pericarditis among civilians.

Surveillance guidelines for smallpox vaccine (vaccinia) adverse reactions.

CDC and the U.S. Food and Drug Administration rely on state and local health departments, health-care providers, and the public to report the occurrence of adverse events after vaccination to the Vaccine Adverse Event Reporting System. With such data, trends can be accurately monitored, unusual occurrences of adverse events can be detected, and the safety of vaccination intervention activities can be evaluated. On January 24, 2003, the U.S. Department of Health and Human Services (DHHS) implemented a preparedness program in which smallpox (vaccinia) vaccine was administered to federal, state, and local volunteers who might be first responders during a biologic terrorism event. As part of the DHHS Smallpox Preparedness and Response Program, CDC in consultation with experts, established surveillance case definitions for adverse events after smallpox vaccination. Adverse reactions after smallpox vaccination identified during the 1960s surveillance activities were classified on the basis of clinical description and included eczema vaccinatum; fetal vaccinia; generalized vaccinia; accidental autoinoculation, nonocular; ocular vaccinia; progressive vaccinia; erythema multiforme major; postvaccinial encephalitis or encephalomyelitis; and pyogenic infection of the vaccination site. This report provides uniform criteria used for the surveillance case definition and classification for these previously recognized adverse reactions used during the DHHS Smallpox Preparedness and Response Program. Inadvertent inoculation was changed to more precisely describe this event as inadvertent autoinoculation and contact transmission, nonocular and ocular vaccinia. Pyogenic infection also was renamed superinfection of the vaccination site or regional lymph nodes. Finally, case definitions were developed for a new cardiac adverse reaction (myo/pericarditis) and for a cardiac adverse event (dilated cardiomyopathy) and are included in this report. The smallpox vaccine surveillance case definitions presented in the report can be used in future vaccination programs to ensure uniform reporting guidelines and case classification.

Behavior and beliefs about influenza vaccine among adults aged 50-64 years.

OBJECTIVE: To examine demographics and beliefs about influenza disease and vaccine that may be associated with influenza vaccination among 50- to 64-year-olds. METHODS: A national sample of adults aged 50-64 years surveyed by telephone. RESULTS: Variables associated with receiving influenza vaccination included age, education level, recent doctor visit, and beliefs about vaccine effectiveness and vaccine safety. Beliefs about influenza vaccination varied by race/ethnicity, age, education, and gender. CONCLUSION: The finding of demographic differences in beliefs suggests that segmented communication messages designed for specific demographic subgroups may help to increase influenza vaccination coverage.

An analysis of rotavirus vaccine reports to the vaccine adverse event reporting system: more than intussusception alone?

BACKGROUND: The rhesus-human rotavirus reassortant-tetravalent vaccine (RRV-TV) was licensed on August, 31, 1998, and subsequently recommended for routine infant immunizations in the United States. After approximately 1 million doses had been administered, an increase in acute risk of intussusception in vaccinees led to the suspension of the use of RRV-TV and its withdrawal from the market. These postmarketing safety studies focused on a single adverse event (intussusception) and, to minimize the risk of a false-positive finding, accepted only cases that met a strict case definition. Safer rotavirus vaccines are needed to prevent the substantial global morbidity and mortality caused by rotavirus infections; their development and future use may benefit from a better understanding of the postmarketing safety profile of RRV-TV beyond intussusception. OBJECTIVE: To characterize more completely the postmarketing surveillance safety profile of RRV-TV more completely by review and analysis of Vaccine Adverse Event Reporting System (VAERS) case reports to better understand 1) whether severe adverse events other than intussusception may have occurred after RRV-TV and 2) the likely scope of gastrointestinal illnesses, of which the previously identified, highly specific intussusception cases may account for just a fraction. SETTING AND PARTICIPANTS: Infants vaccinated with RRV-TV and other vaccines in the United States and for whom a report was submitted to VAERS during September 1, 1998, to December 31, 1999. METHODOLOGY: To detect adverse events of interest other than intussusception, we used proportional morbidity analysis to compare the adverse event profile of VAERS reports among infants who received routine vaccines including RRV-TV (after excluding confirmed and suspected intussusception reports) with infants who received identical vaccine combinations but without RRV-TV. Next, to better capture all described diagnoses, signs, and symptoms associated with the suspected adverse events, a set of new codes was developed and assigned to each VAERS report. All 448 nonfatal RRV-TV-associated reports (including intussusception) were recoded manually from the clinical description on the VAERS report and categorized into clinical groups to better describe a spectrum of reported illnesses after the vaccine. Each report was assigned to one of the following hierarchical and mutually exclusive clinical groups: 1) diagnosed intussusception; 2) suspected intussusception; 3) illness consistent with either gastroenteritis or intussusception; 4) gastroenteritis; 5) other gastrointestinal diagnoses (ie, not consistent with intussusception or rotavirus-like gastroenteritis); and 6) nongastrointestinal diagnoses. RESULTS: Even after excluding intussusception cases, a higher proportion of RRV-TV reports than non-RRV-TV reports included fever and various gastrointestinal symptoms, most notably bloody stool but also vomiting, diarrhea, abdominal pain, gastroenteritis, abnormal stool, and dehydration. Distribution of RRV-TV reports by clinical groups was as follows: diagnosed intussusception (109 [24%], suspected intussusception (36 [8%]), and illness consistent with gastroenteritis or intussusception (33 [7%]), gastroenteritis (101 [22%]), other gastrointestinal diagnoses (10 [2%]), and nongastrointestinal outcomes (159 [35%]). The median time interval between vaccination and illness onset decreased incrementally among the first 4 clinical groups: from 7 days for diagnosed intussusceptions to 3 days for gastroenteritis. CONCLUSIONS: Intussusception and gastroenteritis were the most commonly reported outcomes; however, a substantial number of reports indicate signs and symptoms consistent with either illness, possibly suggestive of a spectrum of gastrointestinal illness(es) related to RRV-TV. Although VAERS data have recognized limitations such as underreporting (that may differ by vaccine) and are nearly always insufficient to prove causality between a vaccine and an adverse event, this safety profile of RRV-TV may aid better understanding of the pathophysiology of intussusception as well as development of future safer rotavirus vaccines.

Adverse event reporting rates following tetanus-diphtheria and tetanus toxoid vaccinations: data from the Vaccine Adverse Event Reporting System (VAERS), 1991-1997.

Since 1966, the Advisory Committee on Immunization Practices (ACIP) has recommended tetanus-diphtheria toxoid (Td) be used instead of single antigen tetanus toxoid (TT) because, while both vaccines protect against tetanus, only Td protects against diphtheria. Despite this recommendation, approximately 2.5 million doses of TT were distributed annually from 1991 to 1997. One possible explanation for the continued use of TT is concern about the relative safety of Td. Small clinical trials found Td to be associated with a higher rate of local vaccine-associated adverse events (VAEs) than TT. To determine if the findings from the trials would hold up on a larger scale, we compared the rate of reporting to the Vaccine Adverse Event Reporting System (VAERS), a passive reporting system, after either vaccine from 1991 to 1997. There were 40 reports per million doses of Td, and 27 reports per million doses of TT, for a reporting rate ratio of 1.4. Reporting rates to VAERS are lower than the rates of VAEs identified in the clinical trials, but the magnitude of the difference in VAEs following TT versus Td is similar. While reporting rates are lower after TT than Td, rates of reported VAEs after both vaccines are low.

Adverse event reports following vaccination for Lyme disease: December 1998-July 2000.

CONTEXT: The vaccine adverse event reporting system (VAERS) monitors vaccine safety post-licensure. Although events reported to VAERS are not necessarily causally associated with vaccination, VAERS reports can be used to identify possible safety concerns that occur at too low a rate to have been identified prior to licensure. OBJECTIVE: To evaluate adverse events following Lyme disease vaccination reported to VAERS during the first 19 months of the vaccine's licensure. DESIGN, SETTING, AND PARTICIPANTS: Analysis of all VAERS reports of adverse events following vaccination for Lyme disease in the US from 28 December 1998 to 31 July 2000. MAIN OUTCOME MEASURE: We evaluated reported adverse events for unexpected patterns in age, gender, time to onset, dose number, and clinical characteristics and compared them to adverse events observed in clinical trials of this vaccine. RESULTS: Over 1,400,000 doses were distributed and 905 adverse events were reported to VAERS, 440 in men and 404 in women, with ages ranging from 10 to 82 years. The majority (56%) of adverse events occurred after administration of the first dose. The most frequently reported adverse events were arthralgia (250), myalgia (195), and pain (157). There were 59 reports coded as arthritis, 34 as arthrosis, 9 as rheumatoid arthritis, and 12 as facial paralysis. Sixty-six (7.4%) events were classified as serious, involving life-threatening illness, hospitalization, prolongation of hospitalization, persistent or significant disability/incapacity, or death. Twenty-two hypersensitivity reactions were reported. CONCLUSION: Based on reporting to VAERS, we did not detect unexpected or unusual patterns of reported adverse events following Lyme disease vaccine administration, other than hypersensitivity reactions, compared with adverse events observed in clinical trials.

Advanced age a risk factor for illness temporally associated with yellow fever vaccination.

In 1998, the Centers for Disease Control and Prevention was notified of severe illnesses and one death, temporally associated with yellow fever (YF) vaccination, in two elderly U.S. residents. Because the cases were unusual and adverse events following YF vaccination had not been studied, we estimated age-related reporting rates for systemic illness following YF vaccination. We found that the rate of reported adverse events among elderly vaccinees was higher than among vaccinees 25 to 44 years of age. We also found two additional deaths among elderly YF vaccinees. These data signal a potential problem but are not sufficient to reliably estimate incidence rates or to understand potential underlying mechanisms; therefore, enhanced surveillance is needed. YF remains an important cause of severe illness and death, and travel to disease-endemic regions is increasing. For elderly travelers, the risk for severe illness and death due to YF infection should be balanced against the risk for systemic illness due to YF vaccine.