Factors influencing participation in national immunization days in Kumasi, Ghana

A study of the factors influencing participation in national immunization days (NID) in Kumasi, Ghana was carried out between the April and June of 1999. Polio-immunization coverage during NID was assessed among children aged < 5 years; > 90% of these children had received polio vaccinations on both of the two previous NID. The mothers who participated most in the NID tended to be those who were better educated and Ghanaian. Mothers who were salaried workers participated fully in NID. Radio and television played a major role in public education about NID, whereas the attitude of health workers was a strong factor that prevented many mothers/caregivers from bringing their children to be immunized. The coverage of the Expanded Programme on Immunization (EPI) was assessed in children aged 12-23 months; nearly 70% of these children were fully immunized. BCG had the highest coverage (97.0%) and measles the lowest (79%). Again, full coverage of the children of mothers who had been educated beyond primary level was higher than that of the other children (75.9% v. 65.2%), and coverage of the children of Ghanaian women was higher than that of the others (70.8%. v. 50.0%). Although the mothers/caregivers raised concerns about the costs of the routine immunizations, these charges apparently did not prevent them from taking their children to be immunized. NID complement the routine EPI-associated work in Ghana, increasing overall polio-immunization coverage. The results of this study will be used to improve the overall performance of immunization programmes, especially in the Kumasi metropolis. Hopefully, sustained, increased polio-immunization coverage will contribute positively towards polio eradication in Ghana.     

EPI vaccines-induced antibody prevalence in 8-9 year-olds in The Gambia

OBJECTIVES: We evaluated antibody prevalence to measles, polio 1 and 3, and tetanus toxoid antibodies in 8-9 year-old children in The Gambia within the framework of the Gambia Hepatitis Intervention Study (GHIS), a large vaccine trial aimed at evaluating vaccine efficacy against hepatitis B virus (HBV) infection, chronic carriage and primary liver cancer in a high risk population. The results of the present survey were compared with a previous survey performed with the same objectives and same methodology but in different children at 3-4 years of age. METHODS: Four clusters of 200 children each were sampled as representative of the whole country. Children would have received BCG, diphtheria-pertussis-tetanus vaccine (DPT), poliovirus vaccine (OPV), measles and yellow fever immunization. The measles haemoagglutination inhibition test (HAI) was used to detect measles antibody. Antibodies to polioviruses 1 and 3 were tested using the standard polio neutralization assay described in the EPI manual (WHO 1990). An enzyme-linked immuno-sorbent assay (ELISA) was used to measure tetanus toxoid antibodies. RESULTS: A high proportion of children were fully vaccinated in both age groups. Measles antibody concentrations were < or =1 : 8 in 8.2% of 8-9 year-old vaccinated children. In the previous survey of 3-4 year-old children this was 11.3%. In the present survey, GMC was lower than in the 3-4 year-old children; 88% of 3-4 year-olds and 89% of 8-9 year-olds had detectable antibody levels against poliovirus type 1. Fewer children at 8-9 years of age had antibodies against poliovirus type 3 than 3-4 year-olds (78%vs. 89% P < 0.001). A significant overall lower proportion of 8-9 year-old children had detectable tetanus toxoid antibodies compared to 3-4 year-old children (87%vs. 95% P < 0.001), as well as those who received four doses of DPT (90%vs. 97% P < 0.001). Conclusions High vaccine coverage is achieved in The Gambia with EPI. With time the number of vaccinated children who are not protected against measles, poliovirus 3 and tetanus increases. Besides the maintenance of high vaccine coverage in infants and young children, booster doses of some of the EPI vaccines in adolescents should be considered.     

Toward measles elimination in Bahrain--a Middle East country experience

Measles was a leading cause of infant and child morbidity and mortality in Bahrain before the introduction of measles vaccine in 1974. With the establishment of the Expanded Program on Immunization (EPI) in 1981 and the introduction of a second dose of measles vaccine in 1985, coverage for first and second doses of measles vaccine increased to 94% by 1997 and has been sustained >97% since 2001. Measles, mumps, and rubella (MMR) immunization campaigns targeting 12-year-old students were conducted annually during 1998-2006 and achieved coverage of >95%. As a result, the incidence of measles in Bahrain has declined markedly over the past 4 decades, to 2.7 cases per million persons in 2009. Recent confirmed measles cases have occurred sporadically, in undervaccinated children or in infants too young or adults too old to receive measles vaccine. Bahrain has made significant progress toward measles elimination by sustaining high immunization coverage and strengthening case-based measles surveillance activities. Further success will depend on improved identification and immunization of undervaccinated expatriate workers and their families.     

Thailand Expanded Program on Immunization: a ten-years review of coverage and impact on EPI target diseases

The national immunization coverage in Thailand for all types of vaccine has been steadily increasing since 1978, when the EPI was formally launched. The coverage in 1987 was 96% for BCG, 75% for DPT, 74% for OPV, and 60% for TT. Measles vaccine, which started only in late 1984, had the lowest coverage, 51%, in 1987. During the period 1982-1987, the drop-out rates between the first and third dose of DPT and OPV decreased dramatically from 69% to 13% and from 42% to 13% respectively. Sampling surveys of immunization coverage showed higher coverage for DPT and OPV than those from reporting in all regions, especially in the capital city which has a high concentration of the private health sector. Only the northeastern region had less coverage from surveys than from reporting. Following the launch of EPI, the disease incidence demonstrated a clearly downward trend for diphtheria, poliomyelitis, and measles, while in the case of pertussis and neonatal tetanus, slower of still fluctuating declines were observed. The reported age-specific incidences per 100,000 population in 1986 for children 0-4 years were as follows: 4 for diphtheria, 0.9 for poliomyelities, 180 for measles, 14 for pertussis, and 10 for tetanus.     

Pulse polio programme: an overview of parent's perception.

India is contributing large number of total world's polio cases. The present study was carried out with the objective to assess the knowledge of the parents regarding pulse polio and their perception towards pulse polio and other immunization. The study revealed that children of all age groups participated in PPI though the coverage was low in 37-48 and 49-60 month age group. In all 30.5% children of respondents could not get OPV in the previous year and they came for the first time to the PPI centre. A significant finding of the study was the status of children regarding other immunization, as 59.5% of the respondents were not immunizing their children for other vaccines. In the present study, 73.2% of the respondents could tell correctly about pulse polio. Predominant source of information about pulse polio was found to be electronic media (55.8%) followed by health workers (20.9%). Only 8.4% respondents opined that distance of PPI centre was far away from their residence.     

Knowledge and practice of mothers regarding pulse polio immunization in National Capital Territory of Delhi

Poliomyelitis continues to be a major public health problem in India leading to high morbidity and mortality among children under age 5 years. To address this problem, pulse polio immunization (PPI) on two National Immunization Days was conducted in the country in 1995. This paper presents findings of a study that was conducted in the National Capital Territory of Delhi to examine mothers' knowledge regarding PPI and routine Oral Polio Vaccine (OPV) immunization schedule and their practice regarding the availing of its services. A total of 481 mothers participated in the study. Findings showed that 97.7% of mothers were aware of this special poliomyelitis vaccination program, while 2.3% were unaware of it. 75% of mothers correctly reported the age group of children receiving OPV to be less than 3 years, while 11% reported that it was being given to all age groups. Moreover, awareness of mothers regarding some aspects of routine OPV immunization was very low. 43% of mothers had incorrect knowledge regarding age of initiation of OPV, and 68% had incorrect knowledge regarding the number of primary doses of OPV. Given the consistently high coverage of the three primary doses of OPV in Delhi, these findings could be explained on the basis of poor emphasis of information, education, and communication activities in routine functioning by health professionals and paramedical workers.     

Wild poliovirus circulation among healthy children immunized with oral polio vaccine in Antananarivo, Madagascar

From July 1995 to December 1996, 3185 stool specimens from healthy children aged 6-59 months attending 6 dispensaries in the Antananarivo area were examined for poliovirus. The children had been routinely immunized according to the Expanded Programme on Immunization (EPI) schedule and received the last dose of oral polio vaccine (OPV) more than 1 month before stool collection. 99.4% of the children were immunized with at least 3 doses of OPV. HEp-2 cell culture revealed virus infections in 192 stools (6.0%), including 9 poliovirus (0.3%) and 183 nonpolio enterovirus isolates (5.7%). Infections occurred throughout the year, but incidence was higher during the hot and rainy season (P=0.01). Using a neutralization test with monoclonal antibodies and PCR-RFLP in two genomic regions coding for the VP1 capsid and RNA polymerase, 4 wild polioviruses (3 type 1 and 1 type 3) and 5 vaccine-related polioviruses (2 Sabin 1-like variants, 1 Sabin 2-like and 2 Sabin 3-like) strains were identified. The wild polioviruses were isolated at the beginning and the end of the dry season. Similar RFLP patterns were observed for the 3 wild type 1 polioviruses. Comparison of partial genomic sequences in the VP1/2 A region of 1 of the wild type 1 isolates with 2 wild type strains isolated in Antananarivo in 1992 and 1993 showed a divergence of at least 10% between the strains, suggesting at least two different pathways of transmission during this period. Our findings demonstrate that immunization with 3 doses of OPV did not prevent intestinal carriage of wild poliovirus strains, and that there is a risk of wild poliovirus transmission to susceptible children in the area. Multiple strategies are required to improve immunization coverage in Madagascar.     

HIV-infected children vaccination coverage and safety in a Western European cohort: a retrospective study

Since the implementation of highly active antiretroviral therapy in HIV-infected children, response to scheduled vaccines may determinate future morbidity and mortality. The aims of this study have been to describe the current vaccine coverage, vaccine safety and concordance with vaccine recommendations of the 68 HIV-infected children and adolescents followed up in our Unit. Forty-four percent of the children received at least one dose of the oral polio vaccine (OPV). Only 9.1% needed and received a second set of hepatitis B virus immunization because of low vaccine response. Only 14.7% were vaccinated against varicella. Coverages of 82.3% and 100% have been reached with the 23-valent and the 7-valent pneumococcal vaccines, respectively. Meningococcal conjugated vaccine uptake was moderate (80.8%). Influenza annual vaccination coverage was poor: only 22.7% had well-documented yearly vaccines. In our experience, vaccine coverage is lower in those vaccines administered in primary care centres compared with the immunizations given at the hospital. OPV administration did not cause any adverse effect in the children or in their families. Vaccine coverage in HIV-infected children was suboptimal.     

Assessment of functioning of Pulse Polio Kendras and house to house activity in Delhi: is there any scope for improvement?

A cross sectional study was done to assess the performance of Pulse Polio Immunization Booths on National Pulse Polio Immunization day (NID) observed on 2nd December 2001. 55 booths located in Delhi were visited. House to house visits were made on 5 successive days to assess out-reach activities and hold focus group discussions with workers and mothers of the beneficiaries. Majority of the booths were within walking distance (96.4%) and accessible (94.5%) to the beneficiaries, had adequate trained staff reporting in time (88.5-90.4%), displayed IEC material (89.1%), marked the tally sheets in a correct manner (86.5%) and were administering polio vaccine within acceptable norms. Correct knowledge regarding vaccine vial monitor (VVM) was present among workers of 82.7% booths. The marking of children was not being done correctly in 38.2% booths. Efforts to disseminate key messages of next date of NID and routine immunization schedule, information about the disease and it's impact on life and removal of misconceptions regarding polio was observed to be poor (28.9-48.1%). During house-to-house visits coverage was found to be excellent barring a few isolated cases of unimmunized children due to various reasons. The finding of the study implies increased focus on training of the workers manning these booths, especially on dissemination of key messages and information about early symptoms and signs of polio, removal of misconceptions, correct marking of the children and houses and countering resistance to immunization.     

Measles vaccination coverage during poliomyelitis national immunization days in Burkina Faso, 1999

In 1999, Burkina Faso added measles vaccine during the second round of its poliomyelitis national immunization days (NIDs). A cluster survey was conducted in each of the country's 53 health districts to assess vaccination coverage achieved by the campaign. Forty-four percent of children aged 9-59 months had a documented prior measles vaccination, and 88% were vaccinated during NIDs. Eighty-five percent of children not previously vaccinated received measles vaccine during the campaign. Although routine vaccination coverage varied substantially among children from various socioeconomic groups, the campaign appeared to almost equally reach all groups of children surveyed. Poliovirus vaccine coverage was 90% when measles vaccine was added to the campaign, compared with 88% during the first round. In Burkina Faso, the addition of measles vaccine to poliomyelitis NIDs achieved greater equity in measles vaccination coverage according to a number of socioeconomic factors without compromising the coverage of poliovirus vaccination.     

Reasons for non-immunization of children in an urban,low income group in North India

A study was undertaken on 500 children under the age of 5 years belonging to a low income group. All were attending the paediatrics outpatient department of a large teaching hospital in New Delhi, India. Only 25% were found to have received complete primary immunization as per the National Immunization Schedule (bacille Calmette-Guérin at birth, three doses of diphtheria, pertussis and tetanus and oral poliovirus vaccine at 6,10 and 14 weeks and measles vaccine at 9 months).The major reasons for non-immunization of the children were: migration to a native village (26.4%); domestic problems (9.6%); the immunization centre was located too far from their home (9.6%); and the child was unwell when the vaccination was due (9%).Twelve per cent of mothers could not give any reason for non-immunization. In addition to the migration of children to rural areas, the other significant finding was an indirect effect of intensive OPV administration as part of polio eradication initiative. The lack of awareness and fear of side effects constituted a small minority of reasons for non-immunization.     

Changes in Expanded Program for Immunization coverage for mother and child in Krakor, Cambodia 1996--1998

We evaluated a training intervention aimed at enhancing the roles of health centre staff, Village Health Volunteers (VHVs) and Traditional Birth Attendants (TBAs) within the Expanded Program for Immunization (EPI) in the district of Krakor, Cambodia. We conducted population-based surveys to determine the coverage of the EPI at baseline (1996) and after the intervention (1998), using data from health cards for mothers and their children and history data. Statistically significant changes over the 2-year period were apparent for tetanus, BCG, polio and DTP, supporting the positive impact the training intervention had on immunization coverage in the district.     

Experience in global measles control, 1990-2001

Worldwide during the 1980s remarkable progress was made in controlling measles through increasing routine measles vaccination to nearly 80%. In 2000, an estimated 777,000 measles deaths occurred, of which 452,000 were in the African Region of the World Health Organization (WHO). In 2001, WHO and the United Nations Children's Fund published a 5-year strategic plan to reduce measles mortality by half by 2005. Strategies include providing a second opportunity for measles immunization to all children through nationwide supplementary immunization activities, increasing routine vaccination coverage, and improving surveillance with laboratory confirmation of suspected measles cases. In 2000, over 100 million children received a dose of measles vaccine through supplementary immunization activities, a number projected to increase during 2002-2005. Current systems for monitoring measles vaccination coverage and disease burden must be improved to accurately assess progress toward measles control goals.     

Facilitating the WHO expanded program of immunization: the clinical profile of a combined diphtheria, tetanus, pertussis, hepatitis B and Haemophilus influenzae type b vaccine.

BACKGROUND: Vaccines are important weapons in the fight against infectious diseases. The World Health Organization (WHO) Expanded Program on Immunization (EPI) has been extended to include recommendations for hepatitis B and Haemophilus influenzae type b (Hib) vaccinations. The WHO has recommended that combined vaccines be used where possible, to reduce the logistic costs of vaccine delivery. This paper reviews the efficacy, safety and cost-effectiveness of Tritanrix-HB/Hib, the only commercially available combined diphtheria, tetanus, whole cell pertussis, hepatitis B and conjugated Hib vaccine. METHODS: The immunogenicity and reactogenicity results of five published clinical trials involving Tritanrix-HB/Hib in a variety of immunization schedules and countries were reviewed. Based on these data and cost-effectiveness studies, an assessment of its suitability for use in national immunization programs was made. RESULTS: Tritanrix-HB/Hib has shown excellent immunogenicity in clinical trials using a variety of schedules, with no reduced immunogenicity observed for any of the components of the combined vaccine. It has similar reactogenicity to DTPw vaccines alone. Pharmacoeconomic analyses have shown combined DTP-HB/Hib vaccines to be cost-effective compared to separate vaccines. CONCLUSIONS: Replacement of DTPw vaccination by Tritanrix-HB/Hib can be done without modifying the existing national immunization programs. This should facilitate widespread coverage of hepatitis B and Hib vaccinations and their rapid incorporation into the EPI.     

Immunization in urban Southeast Asia

By the year 2000 half the population in the world is expected to reside in large urban areas. "Improving immunization services to the disadvantaged in urban areas" is considered one of the priorities for the Expanded Programme on Immunization (EPI). A review of the current situation with regard to immunization coverage and disease surveillance in urban Southeast Asia shows that acceleration of immunization activities in urban areas is needed to achieve and sustain the goal of Universal Child Immunization by the year 1990.     

Standards for immunization practice for vaccines in children and adults

Administration of vaccines is a continuing challenge. In childhood immunizations, many of the goals for national coverage rates by 2000 were achieved and the goal of annual influenza immunization for adults 65 years of age and older was reached. These successes in childhood immunization rates have led to record low numbers of cases of many vaccine-preventable diseases, such as measles and Haemophilus influenzae, type b invasive disease. These diseases will recur, however, as evidenced by the measles epidemic of 1989-1991, if high immunization coverage is not maintained. The development of immunization delivery systems to sustain these high rates in young children is essential to ensure that the 11,000 infants born each day in the United States receive all recommended vaccines, as noted in the recent NVAC report on strategies to sustain success in childhood immunization. For adults, the total economic burden of treating these vaccine-preventable diseases is estimated to exceed $10 billion each year, reflecting in part widespread underuse of vaccines in adults and resulting missed opportunities to prevent diseases such as influenza and pneumococcal infection. The development of standards for immunization practices in children and adults has been an important component in meeting these challenges and ensuring appropriate delivery of vaccines. Periodic review and updating is necessary and revision of the standards for adults by the NCAI and NVAC, pediatric standards, and those of the IDSA currently are undergoing revision. Most importantly, however, standards for immunization practices should be promulgated widely to all health care professionals to ensure that all segments of the population benefit from the availability of highly effective and safe vaccines.     

Successful control and impending elimination of measles in the Islamic Republic of Iran

Measles is still one of the most common infectious killers of children in the world, especially in developing countries. In Iran, during the prevaccine era, 150,000-500,000 cases of measles were reported annually, with a death rate of 10%-15%. After the establishment of Expanded Program on Immunization program in 1984, vaccination rates for the first and second doses of measles vaccine increased to >90% by the mid-1990s, and the number of measles cases decreased to 2652 in 1996. In response to increased numbers of cases in older age groups during 1996-2002, a nationwide measles-rubella vaccination campaign was conducted in 2003, and 33,100,000 persons (99%) aged 5-25 years were vaccinated. During 2004-2009, 221 laboratory-confirmed measles cases (<1 case per million population) were detected, primarily in rural areas and among migrant groups who traveled to or came from high-incidence countries. High routine immunization coverage, low disease incidence, and surveillance system data suggest that interruption of endemic virus transmission might have already been achieved in Iran, but challenges remain and continued efforts are needed to sustain this accomplishment.     

The cost-effectiveness of supplementary immunization activities for measles: a stochastic model for Uganda

Supplemental Immunization Activities (SIAs) have become an important adjunct to measles control efforts in countries that endeavor to achieve higher levels of population immunity than can be achieved in a growing routine immunization system. Because SIAs are often supported with funds that have alternative uses, decision makers need to know how cost-effective they are compared with other options. This study integrated a dynamic stochastic model of measles transmission in Uganda (2010-2050) with a cost model to compare a strategy of maintaining Uganda's current (2008) levels of the first dose of routine measles-containing vaccine (MCV1) coverage at 68% with SIAs with a strategy using the same levels of MCV1 coverage without SIAs. The stochastic model was fitted with parameters drawn from district-level measles case reports from Uganda, and the cost model was fitted to administrative data from the Ugandan Expanded Program on Immunization and from the literature. A discount rate of 0.03, time horizon of 2010-2050, and a societal perspective on costs were assumed. Costs expressed in US dollars (2010) included vaccination costs, disease treatment costs including lost productivity of mothers, as well as costs of outbreaks and surveillance. The model estimated that adding on triennial SIAs that covered 95% of children aged 12-59 months to a system that achieved routine coverage rates of 68% would have an incremental cost-effectiveness ratio (ICER) of $1.50 ($US 2010) per disability-adjusted life year averted. The ICER was somewhat higher if the discount rate was set at either 0 or 0.06. The addition of SIAs was found to make outbreaks less frequent and lower in magnitude. The benefit was reduced if routine coverage rates were higher. This cost-effectiveness ratio compares favorably to that of other commonly accepted public health interventions in sub-Saharan Africa.     

Survey of coverage, strategy and cost of hepatitis B vaccination in rural and urban areas of China

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Cumulative vaccination coverage of measles- and oral polio vaccine obtained by the nationwide survey

In 2002 we estimated the measles cumulative vaccination coverage (CVC) in Japan by randomly selecting a total of 5,000 3-year-old children from the total Japanese population and examining the age in months when they were vaccinated against measles. This survey revealed that in Japan measles CVC at ages 18, 24, and 36 months were 61.7 +/- 1.6%, 79.6 +/- 1.3%, and 86.9 +/- 1.1%, respectively. The results obtained in 2003 revealed that the measles CVC among 3-year-old children in 2003 was higher than that obtained in 2002, with especially noticeable improvement in their period of 12 to 23 months of age. It is estimated that this improvement was attributed to the effort made by many persons concerning vaccination to raise the vaccination rate. In 2003 oral polio vaccine (OPV) CVC was investigated for the first time, in addition to measles CVC. OPV CVC of the first dose at 6, 12, and 36 months of age were 44.2 +/- 1.5%, 85.5 +/- 1.1%, and 94.7 +/- 0.8%, respectively. The results of the second dose at 12, 18, and 36 months of age were 42.3 +/- 1.5%, 73.5 +/- 1.3%, and 90.7 +/- 0.9%, respectively. Even at 36 months of age the CVC level of the second dose of OPV was found to be slightly lower than that of the first dose.