Childhood immunization is the initiation of immunity through the application of vaccines, it is considered important for improving child survival. To date, immunization is a primary health care preventive measure and remains the most cost-effective public health intervention to reduce child morbidity and mortality attributed to infectious diseases [1]. Worldwide, it prevents more than two million deaths each year [2,3]. However, it is unfortunate to say that more than 10 million children in developing countries die every year due to ineffective assessment of valuable interventions such as immunization which would fight common and preventable childhood illnesses [4].

Displaced persons

An internally displaced person (IDP) is someone who is forced to escape his or her home but remains within his or her country's borders. They are often referred to as refugees, although they do not fall within the legal definitions of it [5]. According to the United Nation High Commissioner for Refugees (UNHCR), there were 59.5 million forcibly displaced persons worldwide by the end of 2014 due to persecution, conflict, generalized violence, or human rights violations and this number is only expected to rise due to the numerous ongoing global conflicts [6]. These forcibly displaced populations include both refugees, who cross international borders in their escape from conflict, and internally displaced persons (IDPs) who escape conflict but stay within the borders of their own country [6]. The unique challenges of emergency settings often interfere with the routine health services and prevent access to recommended vaccinations. This disruption of immunization services increases the number of susceptible individuals and creates a population at a particularly high risk for vaccinepreventable diseases (VPDs) targeted for eradication and elimination [7].

GPEI and MRI have shown that populations displaced due to humanitarian emergencies can increase the risk of VPD outbreaks and thereby add to the burden of resources needed to meet VPD eradication and elimination goals [8-12].

Rationale

In Iraq the total number of under-five population in 2016 was 5,651,940 with Kurdistan* involved, and it represented about 14.92% from the total population with a growth rate=2.7% [13]. The number of less than 5 years displaced children in Baghdad Al-Karkh health directorate for 2016 was 1517** and that for Baghdad Al-Resafa was 14194***. Although the mortality of children under 5 years of age has declined to half from 1990 (mortality of about 12.7 million); about 6.3 million still die annually and a quarter of these deaths occur due to vaccine preventable diseases. Specifically, these also include an estimated 1.5 million deaths from diseases for which vaccines are recommended by the World Health Organization (WHO).

*Eman N. Hindi- Ministry of displacement and migration. Information and research directorate

**Dr. Nasik L. Al Fatlawi- Public Health Department. Baghdad Health Directorate/Karkh

***Dr. Hussein A. Mohammed- Health Directorate/Resafa

Increasing vaccine coverage has the potential to save lives, prevent disability, reduce health-care costs, and help eradicate vaccinepreventable diseases. Not only this; but improved vaccine coverage also benefits unimmunized children through herd immunity [14]. Applying national immunization program among Iraqi internally displaced children is of great importance to prevent spread of communicable diseases among under five years' children, thus decreasing morbidity & mortality rates among this age group. In Iraq the total number of displaced families for the year 2017 was 728177, distributed on all Iraqi governorates.

Aim of the study

1)To assess the immunization status among displaced Iraqi children.

2) To find out if there is any association between immunization status and other variables (Parents occupation and educational levels, child order in his family, marital status of the mother, Presence of EPI card before or after displacement).

A cross sectional study was conducted in (4) displacement camps:

• Hay Al Jamia'a camp,

• Al- Gazalia camp,

• Al-Nahrawan camp,

• Zayona camp

The study extended for a period from 1^st of Dec. 2016 to the end of July 2017 with a conveniant sample of 400 under five years internally displaced children. The Data were collected by a questionnaire which was adapted from many researches [15-19] after some modification to some questions, later it was translated into arabic language. The primary form of modified questionnaire was reviewed by 3 expert spescialists (one in community medicine and two in family Medicine),thereafter the study tool was pretested as a pilot study on 25 participants, who were excluded from the study sample to assess the time needed to fulfill the questionnaire and to test the difficulty of questions if present. The questions were made to obtain information concerning the following:

Demographic data of the involved children in the study

Age of the child, gender, birth order, place of delivery and number of living children in a household.

Vaccination status

Divided into 3 groups

• Vaccinated: when the child had completed all vaccines according to Iraqi national immunization program.

• Partially vaccinated: when the child has not completed his vaccinations up to date.

• Unvaccinated: never received any vaccine.

Demographic data of the parents

Educational level of Father/Mother, marital status of the mother, occupation of Father/Mother, source of information about immunization.

Other variables

• Time of displacement

• Distance from health facility/minutes: (Before displaced, after displaced)

• Presence of EPI card ( Before displaced, after displaced)

• Number of vaccination team visits to the household (Before displaced, after displaced)

• Dropouts follow–up by the vaccination team (Before displaced, After displaced)

Statistical analysis

Descriptive statistics was presented in form of 2 graphs, data were introduced into personal computer and statistical package for social science (SPSS) version 22 was used in statistical analysis; Chi square test was used to figure out the significance of association between the immunization status and other variables. P value ≤ 0.05 was set as a cutoff point.

Ethical considerations

• Approval of the scientific committee for the research topic was granted by the scientific council of the Arab board.

• Permission was obtained from the Iraqi ministry of health by an Administrative order directed to the health directorate (Al-Karkh and Al-Resafa) to facilitate the task of obtaining the information from participants.

• Ministry of displacement and migration provided reports about the number of displaced families through the Information and research directorate/department of programs. 2017 (personal communication)

• An article numbered M.O.F/1946 ministry of health/environment, Office of Technical Deputy was addressed to Baghdad Operations Command to facilitate the activity of candidate Thikra H. Hattat to visit Displaced camps to assess the vaccination status to a sample of under 5 year old children at certain localities (AL_Nahrawan, Hay ALjamiaa, AL_Qazalia) in Baghdad.

• An oral consent was obtained by asking every participant if he was willing to fill up the questionnaires after a brief explanation of the general purpose of the study and its objectives

A total of 400 displaced children in camps were included in the present study with a mean (SD)=(36.6 ± 12.3 months), 28.75% of them were in the age group (49-60 months). 52.25% of them were females, and 23.75% were the first in birth order. More than half (52.25%) of displaced children were partially vaccinated (Table 1).

Table 1: Distribution of the children according to demographic variable.

Before displacement, The highest coverage rate (46.2%) for displaced children was for the vaccines Bacillus Calmette Guerin (BCG)+OPV0+first dose of Hepatitis B Virus vaccine (HBV1), while the lowest rate (6.0%) was for the vaccines OPV 1^st booster+TETRA 2^nd booster (Table 2).

Table 2: Coverage rate of vaccines before displacement.

The highest coverage rate (77.5%) for displaced children after displacement was for vaccines OPV1+PENTA1 (Hexa) +ROTA1. However, the lower vaccination coverage (40.5%) was for the vaccines OPV 2^nd+DPT 2^nd booster+MMR (Table 3).

Table 3: Coverage rate of vaccines after displacement.

The average of total vaccination was=55.6%. The highest percentages of educational level for both parents were the primary education. Unfortunately, the majorities (99%) of children fathers were not employed and 5.5% of children mothers were widows (Table 4).

Table 4: Distribution of the parents according to demographic variable.

Table 5 showed that there was a highly significant association between the unvaccinated displaced children and their mother's illiteracy (p<0.001). In addition, the number of fathers who had completed primary school only and the number of unvaccinated children were strongly related (p=0.002). On the other hand, no significant correlation was observed among children of different vaccination status with neither the occupation of mother/father nor the place of delivery.

Table 5: Association between immunization status of the participants and certain variables of parents.

The birth order of the displaced children (≥ 5) had a reliable impact on the vaccination status of the children (p=0.02) While no significant association was observed between children with different immunization status and the following variables: number of living children in a household, presence of EPI card (before and after displacement), vaccination team visits to the household (before displaced), dropouts follow–up team visits (before displacement) and dropouts follow–up team visits (after displacement).

It is worth mentioning that the number of currently unvaccinated displaced children was considerably affected by the absence of EPI before displacement (p<0.001), the absence of EPI after displacement (p<0.001) and the number of regular vaccination team visits (p<0.001) (Table 6).

Table 6: Association between immunization status of the participants and certain demographic variables.

The highest percentage of complete vaccination coverage was observed among the displaced children living in Nahrawan camp and the lowest was in Hay Al Jamia'a and Zayona camps. i.e. unvaccination rate was higher in Nahrawan camp, followed by Hay Al Jamia camp, then Qazalia camp and last Zayona camp (Figure 1).

Figure 1: Distribution of the vaccination status according to camps.

The majority of the participants took a walking time to immunization services of less than 30 minutes whether before or after displacement (Figure 2). It is fortunate that a highly significant increase in immunization coverage for all types of vaccine doses given for children was noted after displacement (p<0.001) (Table 7).

Figure 2: Walking time to immunization service.

Table 7: Association of vaccination doses before and after displacement.

The children of immigrants are at risk of not being fully immunized because of the livelihood insecurity and alienation of their families. Offering antenatal and obstetric care leads to increased immunization uptake; personalized service provision by the health care system significantly increases the likelihood of a child receiving full immunization [17].

Association between parental educational level and the immunization status of children

The current study showed that there was a significant association regarding the parents level of education and the immunization status were, the lower the maternal education level was, the higher percentage of unvaccinated children was, this because the uneducated mothers had no knowledge and lack of aware¬ness of the importance of immunization so they immunize their children less than the educated mothers. This was in agreement with Subhani et al. [16] study in 2015, when they revealed that the probability of immunizing the children by uneducated mothers was 0.378 times less than the educated mothers.

Moreover a similar result was obtained by Maheshwari et al. [17] study in 2014, which confirmed that maternal education has great impact on acceptance of complete vaccination. In unvaccinated category, 55.1% mothers and 42.7% fathers are illiterate. Also Vikram et al. in 2014 found that children of well-educated mothers are more fully immunized than other [20].

Association between the marital status of the parents & their children's immunization status

The present study showed that there was a significant association between the marital status of the parents and the immunization status of children since the majority of the mothers were married. This was similar to that mentioned by a Report of the National Immunization Survey which revealed that children whose mothers were married were more likely to be fully vaccinated than those whose mothers were widowed, divorced, separated or deceased [21]. The same result was also revealed by Adokiya et al. study in 2016 when he mentioned that children whom respondent's age is 40–49 years, have married mothers, of Kusaasi ethnic groupsm Christian and of female gender were more likely to be fully immunized [22]. However these findings were not in accord with Jani et al. in 2008 who found that the marital status and age of the mothers were not seen to be associated with the use of immunization services [23].

Association between occupation of parents & children immunization status

The current study revealed that there was no association between the parental occupations and the immunization status of their children. Similarly, Okoro et al. [24] study in 2015 mentioned that the maternal occupation did not significantly affect the immunization coverage of children in his study. Culturally the father is considered the bread winner and is expected to provide for the financial needs of the family. Relating to this Bugvi et al. [25] working in Pakistan declared in their study that maternal occupation did significantly affect immunization coverage of children in the general population. A poor unskilled mother is unlikely to immunize her child. Moreover, Russo et al. in 2015 found that the mother's occupation remarkably affects the immunization coverage of children [26].

The current study revealed that the birth order of the children and their immunization status were significantly relevant. This was in consistent with Gavrielov-Yusim et al. [27] study in 2012 who concluded that their data substantiate a strong inverse relationship between child’s birth order and the chance of receiving privately purchased voluntary varicella vaccination, he demonstrated that birth order plays a significant role and is inversely associated with vaccination in different ethno-religious and socioeconomic groups. Children from small to average-sized households have a higher chance of vaccination compared to their ranking-corresponding peers from large households [27]. This finding could be related to a reduced mothers’ attention, along with a growing number of children, due to an increase of duties.

The number of siblings per household as a predictor of full immunization

The current study showed that there was no definite association between the sibling's number and the child vaccination. While Elizabeth et al. [28] in 2015 showed that there was a strong relevance between the family size and the children’s full immunization. Mothers with more than four children are two times more likely not to have their children fully immunized compared to those with less than 3. In addition, children from large families have been found to have low vaccine uptake by several investigators. This has been interpreted as reflecting the practical difficulty and expense of having other children at home in taking up the immunization services [29].

Coverage rate of vaccines among displaced children

Before displacement, the highest coverage rate for displaced children was for vaccines BCG+OPV0+HBV1. This may be attributed to the fact that more than three fourth of the children were born in hospitals where these vaccine doses were given soon after birth. This is in agreement with Maheshwari et al. [17] study in 2014 which had the highest coverage rate for the same vaccine doses.

The association between time of displacements & children immunization coverage

The present study demonstrated that there was a highly significant association between the time of displacement (before and after) with the vaccination coverage. Surprisingly, the percentage of vaccination increased highly after displacement. This may be due to the attention drawn to displacement camps whether from the Iraqi government represented by the ministry of health and environment and ministry of immigration and displacement or the non-governmental organizations whether inside Iraq (red Crescent) or globally (WHO, red cross, unicef, human rights) working to maintain descent health services to displaced people.

Association between presence of EPI card (Before/after displaced) and children immunization status

The study demonstrated that the Absence of EPI card (Before/after displaced) was inversely related to the children immunization status. The same findings were declared in Russo et al. [26] in 2015 but with less significant association (P value=0.03) than the current study. Surprisingly, according to results of surveys conducted in African countries [20,30,31] and India, possessing the vaccination card was associated with incomplete vaccination. This was suggested by WHO [32] as might be due to parents over-reporting of vaccine doses for complacency without the possibility of checking the information. This aspect is controversial and may represent a limit to our study. In fact, a recent systematic review on the validity of vaccination card and parents’ recall to estimate vaccination coverage [33] suggests that parents’ recall information should be cautiously interpreted because it might be not reliable. This issue is not mentioned in WHO EPIcoverage survey guidelines [34].

Association between the children immunization status and vaccination team visits to the household (Before/after displacement)

No association was found between the children immunization status and the number of vaccination team visits before displacement. However, the situation is reversed after displacement since there is a good attention and health care provided to the displaced children in camps which raised a positive association (P<0.001). This is in accord with the results mentioned by Kaji et al. in 2016, but it is not in agreement with the Russo et al. [26] in 2015 where a significant difference was found between children immunization status and vaccination team visits to the household. This may be attributed to the difference in sample size collection.

More than half of the displaced children were partially vaccinated and about ten percent were unvaccinated. Before the displacement, the highest vaccine coverage rate was for BCG+OPV0+HBV1 vaccines and the lowest was for OPV 1^stbooster+TETRA 2^nd booster vaccines. While after the displacement, the highest coverage was for the vaccines OPV1+PENTA1(Hexa)+ROTA1 and the lowest coverage was for the vaccines OPV 2^nd+DPT 2^nd booster+MMR.

It was concluded that there was a significant association between the immunization status of different types of vaccines before and after the displacement. Moreover, parents educational level, birth order, marital status of the mother, presence or absensce of the EPI card and vaccination team visits to the household (after displacement) all positively affected the immunization status.