Missed Opportunities For Vaccination Research Articles

Hepatitis B virus infection and vaccination among young injection and non-injection drug users: missed opportunities to prevent infection

Introduction: We examined correlates of HBV infection and vaccination and the missed vaccination opportunities among young injection drug users (IDUs) and non-injection drug users (NIDUs). Methods: Two hundred IDUs and 124 NIDUs aged 15–30 years were studied. Demographics, drug use and sexual behaviors, and health and incarceration history data were collected. Serology was conducted for antibodies to HBV-core antigen (anti-HBc) and HBV-surface antigen (anti-HBs). Presence of anti-HBc indicated past HBV infection; presence of anti-HBs alone indicated past vaccination. Results: More IDUs had been infected with HBV in the past than NIDUs (37% versus 19%, P=0.001). Among male and female IDUs, injection drug use behaviors were significantly associated with past infection. For female IDUs, being African–American and trading sex were also associated with previous infection. Among NIDUs, being female and longer time since sexual debut were associated with past infection. Overall, 11% were vaccinated (10% IDU versus 14% NIDU, P=0.30). Younger age and drug treatment history were associated with vaccination. Most susceptibles (84%) experienced at least one missed opportunity for vaccination. Conclusion: Young drug users remain at high risk for HBV infection. Vaccination rates remain low despite multiple opportunities for vaccination. An integrated HBV immunization effort should be coordinated among venues frequented by young drug users.

Missed opportunities and caretaker constraints to childhood vaccination in rural areas of Uganda

Despite concerted support to vaccination programmes, coverage remains low. While health service reasons for this are known, there is little information on caretaker constraints to vaccination in Africa. To establish the prevalence of missed vaccination opportunities and caretaker constraints to childhood vaccinations. Cross-sectional descriptive study. Caretakers of 408 children aged 12-23 months were interviewed. Kiyeyi, a rural area in Eastern Uganda. Complete vaccination coverage by card was 26.7% while by history and card it was 44.6%. Of the 215 eligible children who sought treatment in a health facility where vaccination could be offered, 59.6% missed an opportunity to be vaccinated while 24.4% of the children missed an opportunity during routine vaccination sessions. Reasons for non-completion of vaccination included caretaker 'not bothered', being busy, or ill and fear of rude health workers. While most caretakers were aware of vaccination and its benefits, none knew the immunisation schedule. The major caretaker constraints were low level of formal education, fear of vaccine side effects, and perceived contraindications to vaccinations. Promotion of formal education for girls and educating mothers and health workers on the timing of vaccinations, their side effects and management might contribute to higher vaccination coverage.

Importance of patients’ perceptions and general practitioners’ recommendations in understanding missed opportunities for immunisations in Swiss adults

Over the last decades, tremendous efforts have been made to strengthen childhood immunisation programs. However, the burden of influenza and pneumococcal infections remains disturbingly high in adults and elderly. We conducted a cross-sectional self-administered mail survey to identify characteristics associated with low use of recommended vaccines in adult patients attending routine primary care appointments in Switzerland. Tetanus vaccination was reported by 84% of respondents aged 16–34, and by only 42% of respondents aged 65 or more. For influenza and pneumococcal vaccination, of high-risk patients (age ≥65 or history of diabetes, kidney, heart, or chronic pulmonary disease), only 41% were on schedule for influenza and 6% for pneumococcal vaccination. Compared with patients from the German- and Italian-speaking areas of the country, patients from the French-speaking region were more likely to report past immunisation against influenza and pneumococcal disease or a recent physician's recommendation for immunisation against influenza, but equally likely to have ever refused influenza vaccination. For all three diseases, area of residence, physician's recommendation for immunisation, and patient's perceived usefulness of vaccination were independently and significantly associated with vaccination status. Although patient's opinion is an important determinant of vaccination coverage in adults, lack of physician's encouragement accounted for most missed vaccination opportunities in this study. The higher vaccination coverage among patients from the French-speaking area suggests that the promotion campaigns carried out in this region effectively improved influenza vaccine use. Interventions designed to increase vaccination coverage in adults must help providers incorporate immunisation in routine health care.

Combining hepatitis A and B vaccination in children and adolescents

Hepatitis A and B are common infections worldwide and their severity is related to the individual's age upon initial infection. Furthermore, when hepatitis B infection occurs in infants, the risk of becoming a chronic carrier is 90%. For hepatitis A, the lower incidence of disease arising from an improvement in living conditions leaves a greater number of children, adolescents and young adults susceptible to residual circulating virus. Consequently, initial infection occurs later in life when clinical illness is more frequent and the rate of morbidity and mortality higher. Although both viruses differ greatly, including their modes of transmission, the overlap in their epidemiology warrants the combination of hepatitis A and B vaccination. The immune response elicited by the combined hepatitis A and B vaccine following a three-dose schedule compares well with the anti-hepatitis A virus (HAV) and anti-hepatitis B sero-responses obtained with monovalent vaccines. In addition, it was shown that the seroprotection rate for anti-hepatitis B increased more rapidly with the administration of the combined vaccine, with values of more than 80% within 1 month after the first two doses (schedule, 0, 1 and 6 months). Currently, according to the World Health Organization recommendations, more than 116 countries are vaccinating their infants and/or adolescents against hepatitis B. Recently, several countries were considering or have decided to begin mass vaccination against HAV (more than fifteen states in the US, Spain (Catalonia), Italy (Puglia)). For these countries, the combination of hepatitis A and B antigens in one single vaccine offers the following advantages: fewer injections for protection against two infections, better compliance, lower implementation costs, and fewer missed vaccination opportunities. Further simplification of the schedule, by reducing the number of doses, would improve the compliance rate as well as being more convenient for the vaccinee. This should translate into a reduction in costs associated with vaccine administration. In some recent vaccine studies, the immunogenicity and safety profile of a two-dose schedule (0 and 6 months) of the adult formulation of the combined hepatitis A and B vaccine was investigated in children aged 1–11 years, as well as in adolescents aged 12–15 years. Current results indicate that this two-dose schedule of the adult formulation could be considered a viable alternative for immunization of children and adolescents.

Susceptibility to tetanus and missed vaccination opportunities in Portuguese women

Maternal and cord sera (96 pairs) were tested to measure antitetanus toxin IgG (ATT IgG) levels, using a commercial enzyme immunoassay. One mother had no detectable antitetanus antibody and four more had levels below those considered to be reliably protective (<160 mIU/ml). All five had been eligible for vaccination during pregnancy according to Portuguese guidelines, although one had received seven lifetime doses of TT. In maternal and cord sera, ATT IgG levels among those not vaccinated during the current pregnancy were significantly lower than among vaccinees ( p<0.0001), but there was no difference between those vaccinated once or twice during pregnancy. Among those not vaccinated during pregnancy, levels of ATT IgG decreased with time since last dose of vaccine ( P=0.0001). The total number of doses of vaccine was not significantly associated after controlling for time since last dose. Missed immunization opportunities occurred among half the women studied. Efforts to sustain protection against tetanus must be intensified.

Do missed opportunities stay missed? A 6-month follow-up of missed vaccine opportunities in inner city Milwaukee children.

To determine 1) the frequency of missed vaccine opportunities (VOs) in inner city children </=3 years of age; 2) whether the recommended vaccine(s) were given within 6 months of the missed opportunity (MO); 3) whether these vaccinations were age-appropriate according to the guidelines of the Advisory Committee on Immunization Practices; and 4) variables associated with MOs. Retrospective chart review with a nested retrospective cohort of children with MOs. Two inner city practice settings in Milwaukee: a community health center and an academic continuity care practice. PATIENTS/SELECTION PROCEDURE: A consecutive sample of 710 visits of inner city children </=3 years of age with VOs, seen between January 1 and March 31, 1995. A VO was defined as any encounter when the child was vaccine-eligible according to Advisory Committee on Immunization Practices guidelines. MOs occurred in 47% (330/710) of the VOs. Only 40% of the children with MOs received age-appropriate immunizations within 6 months; 30% received the vaccinations beyond the age-appropriate time. The remaining 30% either did not return or were not vaccinated on return. The variables significantly associated with MOs were 1) age: children with MOs were older than those without, with a mean age of 15.5 months vs 10.9 months; 2) minor febrile illness; 3) moderate/severe illness; 4) acute illness encounters; and 5) patient's being seen at the community health center. Only 15.5% of all MOs were justified by the presence of moderate/severe illness. VOs are frequently missed in inner city children. Most of the MOs were not justified by the valid contraindication of moderate/severe illness. Sixty percent of the children with MOs did not receive age-appropriate immunizations within 6 months. These children are vulnerable to vaccine-preventable diseases such as measles and pertussis.

Measles Elimination in the Americas

In February 1992, PAHO hosted an Informal Consultation of Measles Elimination in the Americas in Washington, D.C. to review past and current control and elimination efforts, to weigh the scientific and technical feasibility of eliminating measles from the Americas, and to suggest a role for PAHO to further the program. When the measles vaccine 1st appeared in the 1960s, coverage rose, the periods between epidemics increased, and the epidemics involved fewer numbers of people afflicted with measles. The Gambia began vaccinating all 5-year old children in 1967 and it had interrupted measles transmission between 1968-70. It stopped the strategy that achieved this and transmission levels increased. In the US, the Childhood Immunization Initiative begun in 1978 set out to eliminate indigenous transmission of measles by 1982. The US achieved 95% coverage of children entering school and measles incidence fell 99% Yet the US could not eliminate measles. Obstacles included imported measles cases, missed vaccination opportunities, shifting epidemiology of measles to 10-19 year old susceptibles, and high degrees of contagiousness. In 1988, Cuba began its campaign to eliminate indigenous measles transmission. By 1989, it may have achieved transmission interruption. In the last 3 years, authorities have identified only 3 imported cases. The English-speaking Caribbean began a program in 1988. It planned to strengthen routine delivery of measles vaccine to all health facilities and to vaccinate all 1-14 year old children regardless of vaccination status. The mass campaign started in May 1991. By September 1991, authorities had identified only 4 measles cases. Sao Paulo State, Brazil began its mass vaccination campaign (all 1-14 year old children) in 1987. Measles-related deaths fell 98% between 1987-90. The meeting participants believed the Americas could indeed be the 1st region to eliminate measles since it was the 1st to eliminate smallpox and is close to eliminating polio. They hoped PAHO would support present initiatives to eliminate measles in the Americas.

Immunization Practices of Pediatricians and Family Physicians in the United States

To assess current practices and attitudes among pediatricians and family physicians across the United States regarding immunizations. Survey of a random sample of pediatricians and family physicians. Fellows of the American Academy of Pediatrics (N = 746) and American Academy of Family Medicine (N = 429). SURVEY TOPICS: General immunization practices (eg, types of visits during which vaccinations are provided, mechanisms to identify undervaccinated children); and opinions about perceived barriers to immunizations, acceptance of alternative sites for immunizations, and possible immunization requirements for Medicaid and The Special Supplemental Food Program for Women, Infants, and Children (WIC). Pediatricians and family physicians (combined) reported the following: immunizing children during acute illness visits (28%), follow-up visits (90%), and chronic illness visits (77%); using computer or reminder files to identify undervaccinated children (13%); and simultaneously administering four vaccines (diphtheria-tetanus-pertussis, oral poliovaccine, measles, mumps, and rubella and Haemophilus influenzae type b) to an eligible 18-month-old child (66%). Physicians perceived the following as barriers to immunizations: missed preventive visits (40%), vaccine costs (24%), lack of insurance coverage (24%), inability to track undervaccinated patients (22%), incomplete immunization records (12%), and missed vaccination opportunities (12%). Physicians agreed with offering vaccinations during hospitalizations (51%) or emergency department visits (30%), and with immunization requirements for continued eligibility for Medicaid (66%) or WIC (64%). Pediatricians were more likely to vaccinate during chronic illness and follow-up visits, and were more likely to use systems to track undervaccinated children (P < .05); however, most immunization practices and attitudes of pediatricians and family physicians were similar. Physicians who graduated from medical school more recently and those in high-risk urban practices were more likely to vaccinate during acute illness visits, provide simultaneous vaccinations, and favor vaccinations in hospital settings. Vaccination rates might be improved by closer adherence to current immunization guidelines regarding vaccinations during all encounters and simultaneous vaccinations, by developing systems to identify undervaccinated children, and by reducing patient costs for vaccinations. Current immunization practices fall short of the immunization guidelines; changes in individual practice styles will be required to conform with these standards.

Potential Impact of Linking an Emergency Department and Hospital-Affiliated Clinics to Immunize Pre-School-Age Children

To determine whether the use of an urban pediatric emergency department (ED) to immunize pre-school-age children would result in an improvement in the percentage fully vaccinated by the end of the second year of life. A retrospective cohort study of two groups: (1) 100 consecutive children (ED group) enrolled at one of two hospital-affiliated primary care clinics were chosen from the ED patient logs if their second birthday occurred in the 12 months prior to November 1990; and (2) 91 age-matched control children (control group) were chosen at random from the same hospital-affiliated clinics' enrollment logs without regard to ED use. The health care provided during the first 2 years of life for each group was compared. The mean number of visits to the ED in the first 2 years of life by the ED group was significantly greater than that of the control group (2.9 [SD] +/- 2.5 vs 1.1 +/- 1.4; P < .001) during the first 2 years of life. In 67% of ED visits, children would have been well enough to receive a vaccination. Both groups had similar types and numbers of visits to the primary clinics. For example, the ED group had 10 +/- 5 visits by age 2 years compared with the control group, which had 9 +/- 4 visits. There was no significant difference in actual immunization percentages achieved in the clinic, with 62% of the ED group having received four diphtheria, pertussis, and tetanus vaccinations; three oral poliovirus vaccinations; and one measles, mumps, and rubella vaccination by age 2 compared with 69% of control children. There were more missed vaccination opportunities during clinic visits in the ED group (7.4 vs 4.6 per 100 clinic visits; P < .01). If immunizations were offered in the ED to those children who needed them, immunization percentages would have been increased an average of 20% compared with percentages achieved in the clinic alone. Routine vaccinations in the ED would significantly increase immunization percentages in children enrolled in two hospital-affiliated clinics. Close linkage and coordination between the ED and hospital-affiliated clinics may improve preventive health care in urban children who use EDs.

Is an Emergency Department Visit a Marker for Undervaccination and Missed Vaccination Opportunities Among Children Who Have Access to Primary Care?

The purpose of this study was to determine: (1) whether preschool-age patients who utilize the emergency department (ED) are undervaccinated compared with patients having the same primary care provider and (2) whether reducing missed vaccination opportunities in the primary care office can potentially reduce the differences in undervaccination between the groups. This retrospective cohort study involved two groups: 583 ED patients, aged 4 to 48 months, who had primary care providers; and 583 control subjects randomly selected from primary care sites and matched according to date of birth and primary care site. The major outcome variable was the point prevalence of undervaccination, defined as more than 60 days past due for a vaccine at the time of the ED visit, and for control subjects, at the time of their matched patient's ED visit. Demographic variables, vaccination history, presence of chronic illness, and office utilization history were abstracted from office charts. The mean age of all patients was 20.0 months. Emergency department patients were more likely to be boys (61% vs 50%) and had more chronic illness, but did not differ racially from those in the control group. Primary care sites included a hospital-based clinic (n = 137), neighborhood health centers (n = 172), and private practices (n = 274). The undervaccination rates by primary provider type were for (1) hospital clinic ED patients 21.1%, control subjects 19.7%; (2) neighborhood health center ED patients 29.1%, control subjects 22.7%; and (3) private practice ED patients 26.6%, control subjects 14.9%. Overall, the odds ratio of ED patients' being undervaccinated compared with control subjects was 1.8 (95% confidence interval 1.3 to 2.5).(ABSTRACT TRUNCATED AT 250 WORDS)

Missed opportunities for influenza vaccination among children with asthma.

Influenza vaccination is recommended for children with moderate to severe asthma. However, most children with asthma are not vaccinated, in part because many do not make an office visit during the vaccination time period. We studied 247 urban children with asthma to determine the maximum number that could have been vaccinated during a medical visit to a clinic or emergency department. One hundred thirty-nine patients (56%) had at least one visit during the study period. Sixty-five patients (26%) received the influenza vaccination; 74 patients (30%) did not receive the vaccination despite being seen in the clinic or emergency department. One-half of the missed vaccination opportunities at the clinic occurred during nonacute visits. Influenza vaccination rates could be substantially improved by efforts to increase primary care visits during the vaccination time period and to minimize missed vaccination opportunities.