7.3 Monitoring vaccination

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 vaccine utilisation rate.

The results are shared with the vaccination, logistics and health promotion teams. This feedback is important to adjust organisation and motivates the teams.

If coverage is low, the supervisor looks for the reasons (ill-informed population, unsuitable site, limited access (security problems, local events), vaccine shortage, lack of supplies, recording errors, etc.) and makes the necessary adjustments (plans extra vaccination days, changes the composition or number of teams, changes the site or the schedule, steps up or changes the public information, etc.).

If the vaccine utilisation rate is low (< 85%), check the vaccine preparation technique. If the vaccine vial monitors have changed colour, check the cold chain set up.

At the end of the campaign, the campaign coordinator completes and analyses the summary table by site (Appendix 27), by district and overall. 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
• Share information with 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.
 

Estimation methods

• Administrative vaccination campaign coverage 
  The more realistic the population estimates, the more reliable the administrative vaccination campaign coverage will be. It gives an idea of how well the campaign objectives were met but is not representative of the actual measles vaccination coverage in the target population because it does not consider children who were already vaccinated and so did not come to the vaccination sites.
• 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 a high quality assessment of the campaign (more reliable than the administrative vaccination campaign coverage) because the results do not depend on population estimates. 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. The size of the study sample depends not on the size of the target population, but on the expected result and the required accuracy of that result. The representativeness of the sample is crucial for reliable results.
 

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.

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.