Page 13 - IJPS-8-2

International Journal of
Population Studies Accuracy of mother’s reporting on child immunization in Yemen

Since 1998, the World Health Organization (WHO), at boosting coverage levels, vaccination campaigns have
United Nations Children’s Fund (UNICEF), and selected been a constant effort in the country. In 2012 and 2013,
ministries of health have developed the Joint Reporting there were nine polio vaccination campaigns. This may be
Form (JRF) by consensus. The JRF is a standard the reason why polio vaccination coverage has significantly
questionnaire that was sent to all member states to increased in Yemen, rising from 60% in 2006 (MPHP
disseminate consistent data on immunization system and UNICEF, 2008) to 74% in 2013 (International Policy
performance. The information collected in the JRF serves Centre for Inclusive Growth [IPC-IG] and UNICEF, 2014).
as a critical resource for tracking implementation of the It is worth highlighting the importance of mothers’
Global Vaccine Action Plan (GVAP). These initiatives reports in this context, as during most campaigns,
work as key frameworks to guide immunization strategies vaccination may not be recorded on health cards so that
at global and regional levels and progress reports on GVAP survey enumerators can only obtain such information by
(WHO, 2017).
parental recall (Langsten and Hill, 1998). Thus, it is very
While monitoring vaccination surveillance, there important to analyze the accuracy of mothers’ reports.
are two sources of vaccination coverage information, This is because on the one hand, if mothers’ recall leads
administrative records and specific surveys, which can be to coverage overestimation, children may be put at risk, as
used to fill the gaps in administrative data. In this paper, health workers may fail to vaccinate children who still need
we deal with data from specific vaccination surveys, which additional doses. On the other hand, if a mother’s report
usually collect vaccination information through parents’ leads to coverage underestimation, this may cause a waste
recall and/or vaccination cards. Using the Yemen National of resources by vaccinating children already vaccinated
Social Protection Monitoring Survey (NSPMS) data, the (Valadez and Weld, 1992).
aim of the paper was to examine the level of accuracy of
mothers’ recalls on their children’s vaccination histories. 1.1. The history of Yemen’s vaccination initiatives
We did this by comparing mothers’ reporting information Vaccination coverage in Yemen was very low until the
in one round with the vaccination card shown in a 1980s. In the most favorable estimates, at most 10% of
subsequent round. children were vaccinated (the Demographic and Health
The usage of parents’ recall and card information Surveys - DHS -1992 report). According to the WHO
when analyzing vaccination coverage is widespread in the (1988), by the end of the 1980s, Yemen reported at least
literature. Nevertheless, some researchers have questioned ten cases of poliomyelitis per year, and polio vaccination
the validity of parents’ recall of their children’s vaccination. coverage was still lower than 30% (WHO, 1988). In 1990,
Although the literature indicates either over- or with the vaccination for all campaign announced by the
underestimation in parental recall, some researchers still WHO, Yemen adopted national strategies for increasing
conclude that including it in vaccination coverage yields vaccination coverage, reaching 80% of children vaccinated
more accurate estimates (Ndirangu, Bland, Barnighausen, for most vaccines. However, before the mid-nineties, there
et al., 2011; Brown, Monasch, Bicego, et al., 2002; Suarez, was another relapse in vaccination coverage.
Simpson, and Smith, 1997; Langsten and Hill, 1998). Yemen’s vaccination coverage also suffered a noticeable
However, there are also papers questioning parents’ recall drop after the mid-1990s because of a substantial fall in
validity (Murray, Shengelia, Gupta, et al., 2003), and donor support starting in 1990 and a civil unrest taking
others even strongly do not recommend the use of parents’ place in 1994 (WHO and UNICEF, 2008). In 2005, it was
reports once they introduce recall bias (Valadez and Weld, not yet maintaining a consistent upward trend: having
1992; Bolton, Holt, Ross, et al., 1998). improved coverage levels in the early 2000s, it dropped
Vaccination coverage in Yemen has significantly again in mid-2003 (because of another poliovirus outbreak
improved between the nineties and mid-2000s, but there as a result of the spread of the virus from northern
is still a long way to go for the country to reach vaccination Nigeria) and recovered in 2004 (UNICEF, 2005; WHO,
coverage levels recommended by the WHO. For instance, 2006). In 2005, Yemen still had active transmission of the
47% of children aged 12 – 23 months had received imported virus, with 478 cases of children infected with
Diphtheria-Pertussis-Tetanus (DPT) vaccines in 1991 – poliomyelitis in the country. In that year, there were 6
1992 (CSO, PAPCHILD, and MI, 1994), while 60% of them national immunization days (WHO, 2006). The National
had received pentavalent in 2006 (MPHP and UNICEF, Millennium Development Goals Report in 2010 pointed
2008). Since then, coverage has remained at the same out that the national campaigns against polio carried out
level for some vaccines between 2006 and 2013, whereas in Yemen in 2009 eliminated the disease in the country.
for others, coverage has increased in the period. Aiming Despite this, new cases were reported between 2011

Volume 8 Issue 2 (2022) 7 https://doi.org/10.36922/ijps.v8i2.1274