Every evening the head of the vaccination team compiles the tally sheets and sends them to the supervisor. The supervisor checks the data and calculates the vaccination coverage and the vaccine utilisation rate. S/he shares the results with the teams. This feedback is important and motivates the teams.
If coverage is low, the supervisor looks for the reasons (ill-informed population, incorrect choice of site, vaccine shortage, lack of supplies, recording errors, etc.) and makes the necessary adjustments (plans extra vaccination days, changes the composition or number of the teams, changes the site, steps up or changes the public information, etc.).
At the end of the campaign, the campaign coordinator completes and analyses the summary table by site (Appendix 27), by district and the total. That table is used to:
– determine the overall vaccination coverage by age group and location;
– calculate all of the indicators at the end of the campaign;
– provide information to the Ministry of Health officials and partners;
– draft a final report.
7.3.1 Vaccination coverage
The vaccination coverage is the percentage of people immunised in the target population. Once calculated it shows whether the objective was met.
It is calculated for the entire target population and by age group and location.
Number of doses administered
Vaccination coverage = –––––––––––––––––––––––––––– x 100
Administrative vaccination coverage
This is estimated during the campaign based on the data collected each day on the tally sheets and census data. This estimate has certain limitations related to:
– the reliability of the demographic data;
– errors in data collection (when recording) or calculation (when compiling);
– people being vaccinated from localities outside the target area.
Vaccination coverage survey
A survey done at the end of the campaign yields more reliable numbers. It also provides information on activity quality:
– % of invalid doses (doses administered to people not belonging to the target population);
– reasons for non-vaccination;
– number of vaccine doses received;
– vaccination source (campaign or routine);
– percentage of children presenting a vaccination card.
The choice of survey type – cluster survey or lot quality assurance sampling – depends on the objectives and the resources available. While cluster surveys are simpler to do, their design does not allow identification of low coverage areas for planning catch-up vaccination.
7.3.2 Vaccine utilisation rate
Vaccine utilisation rate is a quality indicator. It is calculated by team, by day and by site based on the data collected on the tally sheets.
Number of doses administered
Utilisation rate = –––––––––––––––––––––––––––– x 100
Number of doses used*
* Number of vials opened multiplied by number of doses per vial.
An abnormal utilisation rate (less than 85% or more than 100%) should be checked immediately: the number of vaccine and diluent vials used and remaining, the calculations, the reconstitution conditions, problems with the team, etc.