Immunization is considered as one of the most powerful and cost-effective of all health intervention. It also believed to prevent debilitating illness and disability and saves millions of lives every year. Vaccination is one of the prevention strategies for common childhood illness. It prevents morbidities and mortalities from diphtheria, hepatitis B, measles, mumps, pertussis, polio, rotavirus diarrhea, rubella and tetanus (1).
Immunization schedule for the ten EPI vaccines for the children and tetanus vaccination for women of reproductive age strictly follows WHO recommendations for developing countries and given free of charge in the public sectors and NGO coordinating health facilities. So, national immunization policy recommends for BCG vaccine given at birth, three doses of DPT-HepB-Hib and PCV vaccine given at6, 10 and 14 weeks of age, four doses of oral polio vaccine given at 0, 6, 10, and 14 weeks of age, two doses of Rota vaccine given at 6 and 10 weeks and measles vaccine given at 9 months of age. Recently, inject able polio vaccines have been started and functional now a day at national level. Vaccination service delivery strategies include fixed (static), outreach and mobile sites at government and some of private health facilities. Even though various initiatives and campaigns were used over the years, the coverage of fully immunized children in Ethiopia remains low with high partially immunized children. (4)
Immunization dropout rate is one of the impact target indicators across global, regional and country and designed to track progress toward achieving the goals 2030. Progress in impact goal indicators will be evaluated pre determinant global target and will be defined by WHA in 2021. A detailed description of each impact goal indicators for monitoring, evaluation and action. Immunization is the process whereby a person is made immune or resistant to an infectious disease, typically by the administration of a vaccine (23).
Immunization currently averts an estimated 2-3 million deaths of children every year from Diphtheria, Tetanus, Pertussis (Whooping Cough) and Measles throughout the world
Although Africa has made remarkable progress in immunization services, large numbers of children remain unvaccinated and under-has stalled vaccinated. The performance of routine immunizations in the African region during the last decade for the majority of vaccine delivered antigens. According to a 2013 immunization data report, vaccine coverage was 75 % and Ethiopia has second largest number of incompletely vaccinated children from the region next to Nigeria (2).
Mini EDHS 2019 reveals the coverage of all basic vaccines and/or any vaccination coverage has been strongly associated with better wealth status, better education of care givers, and living in urban areas. Fifty-seven percent of children living in urban areas have received all basic vaccinations compared with only 37% of children in rural areas. Children in the highest wealth quintile (65%) are more than twice as likely to have received all basic vaccinations as children in the lowest quintile (25%). Sixty-five percent of children whose mothers have more than secondary education were received all basic vaccinations compared with 34% of children whose mothers have no education. Coverage of all basic vaccinations is highest in Addis Ababa (83%) and lowest in Afar (20%). (5)
WHO immunization coverage in July 2019 indicated that14 million infants did not receive an initial dose of DTP vaccine pointing to lack of access to an immunization and other health services and an additional 5.7 million are partially vaccinated. Of the 19.7 million more than 60% these children live in 10 countries: Angola, Brazil, the Democratic Republic of the Congo, Ethiopia, India, Indonesia, Mexico, Nigeria, Pakistan and the Philippines. (7)
According to study done in Northwest Ethiopia, showed that full-vaccination coverage for the children aged 12-23 months was 58.4%, while 17% and 24.6% were partially vaccinated and not vaccinated at all respectively and child full vaccination status has a positive association with urban residence, having antenatal care visit, institutional delivery for the study child, vaccination site at health institutions, mothers who knows vaccination schedule of a catchment area, and mothers taking a child for vaccination even if the child is sick. However, mothers who ever-married and their travel time to the nearest vaccination site ≤ 30 minutes were negatively associated with child full-vaccination status.(8)
Globally, about 22.4 million infants failed to receive 3 doses of DTP, leaving large numbers of children susceptible to vaccine-preventable diseases and death. Nearly 8.4 million received at least 1DTP dose, but dropped out before completing the 3-dose series (15)
In study area there was shortage of data which reveals dropout rate and associated factors. Thus, this study was important to fill for the existing information gap and help Aretegna Health Center, Abuker, Jenela and Amir Nure health centers for program planning, policy makers like Harar regional health bureau, woreda health office, health extension workers or health worker and other health related stake holders, especially for future community health life. it also helps as a baseline for future studies.
EDHS 2016 revealed that 69% of children had received the BCG vaccine and 54% had received the measles vaccine. A relatively high percentage of children received the first DPT dose (73%). However, only 37% went on to receive the third dose of DPT. More than eight children of every ten (82%) received the first dose of polio, but only about four in ten (44%) received the third dose. Even though DPT and polio vaccines are often routinely administered at the same time, polio coverage is higher than DPT coverage. According to 2013 health and health related indicators of Ethiopia, the coverage of penta-3 and PCV-3 was 87.6% and 80.4% respectively while that of measles and fully immunized was 83.2%and77.7% respectively (11).
In 2011, nearly 107 million infants (83%) worldwide received at least 3 doses of DTP vaccine; however, approximately 22.4 million failed to receive 3 doses, leaving large numbers of children susceptible to vaccine-preventable diseases and death(15).
Estimated global DTP3 coverage among children aged <12 months in 2014 was 86%, ranging from 77% in African region to 96% in the Western Pacific Region. Approximately, 18.7 million eligible children did not complete the 3-dose series, of which 22%, 12%, 6%, 5% and 4% live in India, Nigeria, Pakistan, Indonesia and Ethiopia respectively. Among them 7.1million (39%) started but did not complete. The report also shows estimated global coverage of BCG(91%), PCV3(86%) and MCV1(85%) (22)
In Ethiopia, it was found that 73.2% of children were fully immunized, 20.3% were partially immunized, and 6.5% received no vaccine .in another study conducted, 76% of the children were fully immunized. Dropout rate was 6.5% for BCG to measles, 2.7% for penta 1 to penta 3, and 4.5% for pneumonia 1 to pneumonia 3 (30).
Other study in Ethiopia in northwest on east Gojam in 2016 result that the overall statuses of children vaccination, 58.4% were fully vaccinated, 17% partially vaccinated and 24.6% not vaccinated. Nearly three-fourths of the children were vaccinated for BCG 72.9% with about three-fourths BCG scar, OPV3 73.4%, penta3 68.7%, PCV1-3 66.6%, rota-2 66.5%, measles (31)67.5% by card. The dropout rate between the first and the third pentavalent vaccine coverage was 3.73%. While dropout rate between BCG and measles was 7.44% (31).
The proportion of partially vaccinated children in Zimbabwe ranged from 13.4% to 56.1% in Rwanda, while the proportion of non-vaccinated children ranged from 0.4% in Burundi to 16% in Ethiopia. The highest vaccine-specific coverage for BCG was in Rwanda 99.1%, measles was in Burundi 93.2%, polio3 was in Rwanda 97.1% and pentavalent3 was in Rwanda 98% while the lowest vaccine-specific coverage for BCG was in Ethiopia 70.5%, measles was in Rwanda 43.6%, polio3 was in Ethiopia 57.7% and pentavalent3 was in Ethiopia 54.4% (32).
The reviewed literatures reported that, research done in Ambo district revealed that mothers' educational and occupational status were the factors that showed significant association with complete vaccination history. Children's mother who was illiterate less likely to be vaccinated than those attended primary school. Regarding the mother’s occupation, housewife or farmers were less likely vaccinate their children as compared to government employed mothers (8).
study done in Ethiopia on risk factors for childhood immunization dropout rate revealed that children from lower wealth quintiles family had lower rates of vaccination completion than the highest quintile family and Children whose mothers had no formal education more likely dropout rate vaccinated as compared to Children whose mothers had higher education (17).
However, another study conducted in Wonago district of Southern Ethiopia contradicts the above study findings. It showed that only family income status was found to be predictor of defaulting from immunization. The other socio-demographic variables such as family size, age of the mother or immediate caretaker, occupational status, ethnicity, religion, parity and educational status were not associated with defaulting (19).
Children's immunization rates have been associated with certain demographic factors, such as parental knowledge regarding immunization and practice, as well as parents’ age, educational level, and employment status. Many studies have indicated that factors such as lack of parents' awareness, misconceptions, and fear of side-effects of vaccines were the most reported reasons for low immunization coverage in countries which allow EPI opting-out. Moreover, a study (29) conducted in Tikrit, Iraq by Abdulrahman and colleagues (2008) found a significant association between immunization completeness and mother's educational level, residence, child sex, mother's age and job respectively. Similar results were reported in Lebanon as vaccination of female children less than 2 years and high parental education were found significantly associated with vaccination compliance (29).