Incomplete Immunization Status Research Articles

Vaccine coverage and determinants of incomplete vaccination in children aged 12-23 months in Dschang, West Region, Cameroon: a cross-sectional survey during a polio outbreak.

BackgroundInadequate immunization coverage with increased risk of vaccine preventable diseases outbreaks remains a problem in Africa. Moreover, different factors contribute to incomplete vaccination status. This study was performed in Dschang (West Region, Cameroon), during the polio outbreak occurred in October 2013, in order to estimate the immunization coverage among children aged 12–23 months, to identify determinants for incomplete vaccination status and to assess the risk of poliovirus spread in the study population.MethodsA cross-sectional household survey was conducted in November-December 2013, using the WHO two-stage sampling design. An interviewer-administered questionnaire was used to obtain information from consenting parents of children aged 12–23 months. Vaccination coverage was assessed by vaccination card and parents’ recall. Chi-square test and multilevel logistic regression model were used to identify the determinants of incomplete immunization status. Statistical significance was set at p < 0.05.ResultsOverall, 3248 households were visited and 502 children were enrolled. Complete immunization coverage was 85.9 % and 84.5 %, according to card plus parents’ recall and card only, respectively. All children had received at least one routine vaccination, the OPV-3 (Oral Polio Vaccine) coverage was >90 %, and 73.4 % children completed the recommended vaccinations before 1-year of age. In the final multilevel logistic regression model, factors significantly associated with incomplete immunization status were: retention of immunization card (AOR: 7.89; 95 % CI: 1.08–57.37), lower mothers’ utilization of antenatal care (ANC) services (AOR:1.25; 95 % CI: 1.07–63.75), being the ≥3rd born child in the family (AOR: 425.4; 95 % CI: 9.6–18,808), younger mothers’ age (AOR: 49.55; 95 % CI: 1.59–1544), parents’ negative attitude towards immunization (AOR: 20.2; 95 % CI: 1.46–278.9), and poorer parents’ exposure to information on vaccination (AOR: 28.07; 95 % CI: 2.26–348.1). Longer distance from the vaccination centers was marginally significant (p = 0.05).ConclusionVaccination coverage was high; however, 1 out of 7 children was partially vaccinated, and 1 out of 4 did not complete timely the recommended vaccinations. In order to improve the immunization coverage, it is necessary to strengthen ANC services, and to improve parents’ information and attitude towards immunization, targeting younger parents and families living far away from vaccination centers, using appropriate communication strategies. Finally, the estimated OPV-3 coverage is reassuring in relation to the ongoing polio outbreak.

Prospective Nationwide Surveillance of Hospitalizations Due to Pertussis in Children, 2006–2010

Frequency of pertussis is highly variable from country to country and it depends on multiple factors including case definitions and type of surveillance systems used. Many countries recently reported an increase of pertussis cases especially in infants and adolescents. From April 2006 to March 2011, 15-year-old patients hospitalized with suspected or proven pertussis were reported to the Swiss Pediatric Surveillance Unit. Patients with ≥14 days of cough plus paroxysms, whooping or post-tussive vomiting fulfilled the clinical case definition of pertussis. For laboratory confirmation, Bordetella pertussis polymerase chain reaction was offered free of charge. Data were available from 159 of 173 reported cases and 130 (90% of them <12 months old) were eligible including 125 laboratory-confirmed B. pertussis infections. Rates per 100,000 population were 2.6 (<16 years) and 38.8 (<12 months), respectively. Most frequent complications were cyanosis (63%) and sleep disturbance (60%); 35 (27%) patients received intensive care and 1 patient died. Source of infection was known in 79 (61%) patients and was mainly a sibling, parent or both. Most patients were unimmunized (65%) or incompletely immunized (30%). The high rate of pertussis hospitalization in young infants established in this surveillance project and the incomplete pertussis immunization status in almost all hospitalized patients require further efforts for improvement. In addition, introduction of pertussis immunizations for all adolescents (in 2013), young adults (in 2012) and pregnant women (in 2013) in Switzerland should increase indirect protection of vulnerable newborns and infants too young to be fully immunized.

Iraqi parents' views of barriers to childhood immunization

Deficiencies in knowledge about immunization among parents often leads to poor utake or errors in immunization dosage and timing. The aims of this study were to determine Iraqi parents' views of barriers to immunization and beliefs about ways to promote immunization. A questionnaire survey was carried out among 528 Iraqi parents with children who had incomplete immunization status. The main barriers to immunization agreed by the parents were lack of vaccine availability (51.5% of parents) and parents' lack of education (42.4%), while 88.4% of parents thought that lack of funding was not an important barrier. More than 60% of the parents suggested promoting childhood immunization via the media, and 77.5% thought that an increase in funding would not remove barriers to childhood immunization. Better vaccine availability in public health clinics and improving parents' literacy might enhance immunization uptake in Iraq.

Couverture vaccinale des grands prématurés à 6 mois et à 2 ans : étude pilote

There are few data examining the vaccine practices for 0- to 24-month-old premature infants born before 33 GW. The aim of the study was to examine the vaccine coverage in this population according to the French schedule at 6 and 24 months. Eighty-seven infants were included in this regional prospective study. The immunization program began late and was initialized principally with DTPCoqHib (63%), usually after the 4th month. Fewer than one infant out of two (45%) had received three doses by 6 months of age. At 2 years of age, the coverage was 99% at 3 doses and decreased to 83% for 4 doses. For the MMR vaccine, the average age of administration was after 15 months, and 95% of infants had received one dose of MMR at 2 years of age. BCG coverage at 2 years of age was 94%, administered on average at 7 months. Forty-seven percent of the infants had received at least one dose of hepatitis B vaccine before 2 years of age, but only 31% had received two doses and a booster at 2 years of age. The adaptation of vaccination practices basically concerns the initial date of vaccination, but the immunization calendar is not recovered at 2 years of age. This should be taken into account for pertussis disease prevention in these young infants during the first 6 months of life, increasing the susceptibility period for this infectious disease. The vaccine practices do not follow the postnatal chronological age of the premature baby according to the schedule recommended for full-term infants and vaccination is begun late. Based on the CSHPF vaccination recommendations, nearly 7 premature infants out of 10 have an incomplete immunization status for DTPCoqHib, hepatitis B, and ROR at 2 years of age. According to the pertussis coverage observed in premature infants, the new recommendations on vaccination of the newborn's care giver and family should be completed before the infant's discharge from the hospital using a new acellular vaccine for adult immunization. The initiation of an immunization program during hospitalization would be beneficial for premature babies still hospitalized after 2 months of age.

Evaluation of the vaccination status in pediatric renal transplant recipients

To assess the immunization status of pediatric renal transplant patients followed at a single center in Brazil, vaccination charts of all patients aged between one and 18 yr were analyzed both pre- and post-transplantation. Appropriate immunization was defined according to the National Immunization Program (routine vaccines) - for all Brazilian children - and the Special Immunobiological Agents Program that also includes special vaccines for immunodeficient or other high-risk children. A total of 46 patients was evaluated (mean age 13.7 yr; range 4-17 yr). Vaccination charts were found to be up to date in only two patients (4.3%) pretransplant and in two (4.3%) post-transplant. Although 36 patients (62.2%) in the pretransplant phase and 24 (52.1%) in the post-transplant phase had been vaccinated according to the National Immunization Program, they had not received the special vaccines indicated for their immunocompromised condition. Therefore, despite being followed at a referral center, almost all patients presented an incomplete immunization status pre- and post-transplant. This probably reflects missed opportunities and medical/parental apprehension related to vaccination of patients with chronic renal insufficiency, dialysis or kidney transplantation. Efforts should be made to ensure adequate vaccination in children with kidney diseases, especially before kidney transplantation.

Seroprevalence and immunization history of selected vaccine preventable diseases in medical students

To evaluate protection against vaccine-preventable diseases in medical students, we obtained data on immunization status and history of diphtheria, tetanus, pertussis, poliomyelitis, measles, mumps, rubella, varicella and hepatitis B from students with elective periods in our institution. Further, serum antibodies against measles, mumps, rubella and varicella-zoster virus (VZV) and hepatitis B surface (HBs) antigen were determined on a voluntary basis. For students with incomplete immunization status or lack of protective antibodies, vaccination was offered for free. Success of catch-up immunizations was serologically confirmed 4 weeks later. From May 1999 to April 2003, 170 students were enrolled; their mean age was 26 years with a median of 25 years (range 22–48 years). Immunization records were complete in 148 (87%), incomplete in 11 (6.5%) and missing in 11 (6.5%) students. Only 26% of the cohort had a complete and up-to-date immunization status. Seroprevalence of IgG antibodies against measles, mumps, rubella, VZV and HBs (≥10 IU/l) in 149 students were 85, 85, 92, 97 and 90%, respectively. Indications for ≥1 catch-up immunization were found in 125 (74%) students and were accepted by 97 of them (78%). Sixty two (99%) of 63 immunized students available for follow-up demonstrated an adequate serological response. In conclusion, the great majority of medical students had immunization gaps. Systematic immunization programmes for medical students should be implemented.

Childhood immunization rates before and after the implementation of Medicaid managed care.

To evaluate trends in childhood immunization coverage after implementation of Medicaid managed care in Tennessee (TennCare) in 1994. Before-and-after study using the Tennessee Department of Health annual cross-sectional survey of children aged 24 months. A mean of 1663 children per year who were randomly sampled during 1986-1999. Completion rate for recommended immunizations by the age of 24 months or younger. A total of 23 044 children were included. The proportion of children continuously enrolled in Medicaid from age 1 to 24 months increased slightly with TennCare. Among children enrolled, immunization rates increased considerably before TennCare (1986-1993) and continued to increase after TennCare (1994-1999), albeit less dramatically. Immunization coverage was significantly lower for children enrolled compared with children not enrolled in fee-for-service Medicaid. Among children enrolled in fee-for-service Medicaid, black children were more likely to be inadequately immunized than white children (40% vs 26%; relative risk [RR], 1.56; 95% confidence interval [CI], 1.40-1.73). These gaps were nearly eliminated after TennCare. An increased proportion of children enrolled in TennCare received immunizations in the private sector. Among children enrolled in fee-for-service Medicaid, those receiving immunizations entirely in the private sector were more likely to have incomplete immunization status than children immunized entirely in the public sector (27% vs 21%; RR, 1.28; 95% CI, 1.20-1.37). Under TennCare and after implementation of the Vaccines for Children program in Tennessee, the difference was not significant. Overall, TennCare had no discernible negative effect on immunization rates in Tennessee and perhaps contributed to decreasing the immunization gap between children enrolled and children not enrolled in Medicaid and between black and white children.

Pourquoi certains enfants sont incomplètement vaccinés à l’âge de 2 ans ?

A survey was conducted in the Province of Quebec to document the factors associated with an incomplete immunization status among 2-year-old children. Parents of 430 completely and 266 partially vaccinated children selected from the computerized vaccination register agreed to participate. The non-simultaneous administration of the 2nd MMR and 4th DPT-P-Hib at 18 months of age was responsible for 46% of incompleteness. The following characteristics were significantly associated with an incomplete immunization status: being a single parent, > or = 2 children in the family, an older age at first immunization (> or = 3 months), parent's preference for postponing the second vaccine when two injections are scheduled for the same visit, perception of lack of information about vaccination, and disagreement with immunization recommendations. One of the key points of this study is the impact of the non-simultaneous administration of the two vaccines at 18 months. Factors such as being a single parent and older age at first immunization might be used to design an early intervention for children who are most likely to be incompletely immunized. Even if parents are favourable towards immunization, they need to be well informed about the associated risks and benefits.

Pourquoi certains enfants sont incomplètement vaccinés à l'âge de 2 ans?

Objective: A survey was conducted in the Province of Quebec to document the factors associated with an incomplete immunization status among 2-year-old children. Methods: Parents of 430 completely and 266 partially vaccinated children selected from the computerized vaccination register agreed to participate. Results: The non-simultaneous administration of the 2nd MMR and 4th DPT-P-Hib at 18 months of age was responsible for 46% of incompleteness. The following characteristics were significantly associated with an incomplete immunization status: being a single parent, ≥ 2 children in the family, an older age at first immunization (≥ 3 months), parent’s preference for postponing the second vaccine when two injections are scheduled for the same visit, perception of lack of information about vaccination, and disagreement with immunization recommendations. Conclusion: One of the key points of this study is the impact of the non-simultaneous administration of the two vaccines at 18 months. Factors such as being a single parent and older age at first immunization might be used to design an early intervention for children who are most likely to be incompletely immunized. Even if parents are favourable towards immunization, they need to be well informed about the associated risks and benefits.

Pattern of Prenatal Care and Infant Immunization Status in a Comprehensive Adolescent-Oriented Maternity Program

To examine the relationship between patterns of prenatal care utilization and the subsequent pattern of preventive infant health care utilization among patients in a comprehensive, multidisciplinary, adolescent-oriented maternity program. We hypothesized that the mothers of incompletely immunized 8-month-olds were less compliant with their own prenatal care appointments than were mothers of fully immunized 8-month-olds. We retrospectively reviewed the medical records of 150 consecutively delivered infants and their adolescent mothers. Data concerning the pattern of prenatal and postnatal use of preventive health care services and potentially confounding maternal characteristics were collected. Of the 150 infants aged 8 months, 22 (14.7%) were incompletely immunized. Mothers of completely and incompletely immunized infants did not differ in age, school enrollment status, or compliance with prenatal appointments. However, the latter group initiated prenatal care later, obtained fewer prenatal visits, returned later for postpartum care, and were more likely to be black and to report inadequate family support after delivery. Three of the 5 characteristics entered a logistic regression function that predicted the risk of incomplete immunizations at 8 months of age: third-trimester initiation of prenatal care (odds ratio, 4.05; 95% confidence interval, 1.19-13.7), inadequate family support (odds ratio, 3.42; 95% confidence interval, 1.17-10.0), and black race (odds ratio, 3.14; 95% confidence interval, 1.19-8.69). The total model chi 2 was 15.8 (P < .001). Among patients in a comprehensive adolescent-oriented maternity program, the timing of the first prenatal visit helps to identify infants who are at increased risk for incomplete primary immunization status. Our findings favor preferential allocation of scarce, costly outreach services to infants born to adolescent mothers who enter prenatal care during the third trimester.

Lack of early antitoxin response to tetanus booster

Tetanus immune globulin (TIG) continues to be recommended in persons with tetanus-prone wounds who have incomplete or unknown tetanus immunization status. The aim of this study was to determine whether, following a booster dose of tetanus toxoid in adults who had not been immunized in the previous 10 years, there was an antitoxin response to tetanus toxoid booster within 4 days. Thirty-one adults were investigated, baseline levels for tetanus antitoxin assayed using an ELISA technique, and an injection of adsorbed tetanus toxoid (0.5 ml) given. Blood samples for tetanus antitoxin levels were taken at daily intervals for the 4 days following immunization. Tetanus boosters following the primary course but before the present study did not significantly increase the levels of pre-study tetanus antitoxin and following the study booster there was no difference between the preboost levels and the levels on days 1 to 4. This finding indicates that the present recommendations for the use of TIG in tetanus-prone wounds are appropriate.