Immunization is an important means of ensuring immunity against various diseases. Acquired immunity is attained through either passive or active immunization. Passive immunization refers to the transfer of active humoral immunity, in the form of “ready-made” antibodies, from one individual to another [1.2]. It can occur naturally by transplacental transfer of maternal antibodies or induced artificially by injecting a recipient with exogenous antibodies targeted to a specific pathogen or toxin [2, 3]. Artificial immunization is used when there is a high risk of infection and insufficient time for the body to develop its own immune response. Active immunization which produces antibodies against a specific agent after exposure to the antigen can be acquired through either natural infection with a microbe or through administration of a vaccine that can consist of attenuated (weakened) pathogens or inactivated organisms [2, 4].
Active artificial immunization is provided in most countries through routine immunization or Expanded Program on immunization (EPI) and as part of primary health care approach [5]. The global effort to use vaccination as a public health intervention began in 1974 when the World Health Organization (WHO) launched the EPI [6, 7]. Most countries since then have made significant efforts in immunization activities which ensure that children are protected from vaccine preventable diseases.
Just as other countries, Ghana launched the EPI in June 1978 with six antigens – BCG, measles, diphtheria-pertussis‐tetanus (DPT) and oral polio for children under one year of age [8]. This was intended to reduce morbidity and mortality of vaccine preventable diseases which then contributed significantly to both infant and child mortality in the country. The EPI was a government policy to ensure all children receive these vaccines before their first birthday of life. The number of vaccines given to children under five years in Ghana is now 12 [9]. In order to reduce burden of diseases in children to ensure their overall well being, there are annual targets for various districts and the nation as whole. These targets are set for health personnel to work immensely to ensure that vaccine preventable diseases burdens are reduced in children. Also, these vaccines are very expensive and some organizations and health development partners that help purchase these vaccines want to get good output of good coverage. Various strategies are used to deliver immunization in many countries. These include static vaccination posts, outreach services as well as campaigns or national immunization days [10]. All these methods of delivery aim to reach out to most of the unreached populations and achieve high coverage so that vaccine preventable diseases burden in the population would reduce.
After immunization, data is generated through recording the number of children immunized and vaccines used as part of administrative monitoring. Flow of immunization data begins at the health facilities where vaccines are administered. Vaccination is conducted by health personnel in these facilities as either static or outreach services in catchment communities. It is also carried out in hospitals and private facilities. Typically, when a health worker administers a dose of vaccine, the date of vaccination is immediately recorded on the child’s individual vaccination card and on the immunization register and the dose is tallied on an appropriate sheet allowing for the easy re-counting of all doses provided. The registers and the tally sheets are kept in these facilities where the vaccinations are performed. These health facilities usually report these immunization data to the district/municipal health directorates on regular basis (monthly or quarterly).
At the district level, health personnel receive the reports and check for quality such as completeness, timeliness, accuracy and follow up on late, incomplete, inaccurate reports. All facilities reports within the district’s jurisdiction are aggregated and a report sent to the regional level. The region as well collates all districts reports and send to the national level. At the national level (national headquarters of the national immunization services/programme), collation of the regional reports is made. Subsequently, the country sends the national data to the international community as an official report to WHO and United Nations Children and Educational Fund.
Immunization coverage over the past decades has increased considerably in most countries. This can be attributed to the commitment by most countries to meeting the then (MDG) 4 of reducing under-5 mortality rate by two thirds of the 1990 levels by 2015 of which immunization plays a vital role in its realization. Substantial investments continue to be given by international agencies like Global Alliance for Vaccines and Immunizations, JICA and WHO to improve immunization coverage in developing countries. However, the quality of data generated by these countries continue to in contention. Data are usually overreported or underreported from level of the health system to another [5, 11, 12]
It was reported by [5] that, numbers of all vaccine types were different when tally sheets, facility registers and district reports were compared. Also, [13] made the case that there were discrepancies between tallied data at the vaccination delivery sites and reported data to the MHD. [14] assessed Ghana’s information system and found that concordance between facility monthly report and facility vaccination tally sheets was only 38%. The integrity and quality of our routine administrative data due to inconsistencies, inaccuracies, errors in our data reporting have always been an issue. [15] confirmed this in their study of 45 countries where officially reported diphtheria tetanus-pertussis vaccine (DTP3) coverage was higher than what was reported from household surveys. The Ho municipality has seen persistent drops of immunization coverage from 2013 to 2015 and one of the worst performers in the country [16]. There is therefore a tendency by lower level health facilities to overreport immunization data to evade continuous reprimands by high level staff. Also, though data verification takes place at the facility level on regular basis, supervisors concentrate more on consistency checks between data in the facility reports and the number of vaccines received. The objective of the study was to assess the quality of routine immunization data for 2015 generated in Ho central.