Calculating required doses based on the immunization schedule
In addition to calculating the number of people in the target population, you also need to know the number of doses required in the EPI schedule in order to immunize everyone (total coverage). You learned about the EPI schedule in Study Sessions 2 and 3, but we repeat the key points in Table 5.2. We use the letters ‘dn’ to represent the number of doses in calculations.
Table 5.2 Vaccine schedule by age and number of doses.
| Vaccines | Schedule by age | Number of doses in schedule (dn) |
|---|---|---|
| BCG | At birth | 1 |
| Pentavalent | At 6, 10 and 14 weeks | 3 |
| Polio (OPV) | At birth, 6, 10 and 14 weeks | 4 |
| PCV10 | At 6, 10 and 14 weeks | 3 |
| Measles | At 9 months | 1 |
| Tetanus toxoid | On reaching childbearing age
Ideally all women of childbearing age should receive five doses of tetanus toxoid. |
At least 2 |
If you have an estimated 200 surviving infants in your kebele, how many doses of pentavalent vaccine would be needed to complete the EPI schedule for all these children? Use the data on % of total population in Table 5.1.
The target population is 170 surviving infants, so you would need 510 doses to complete the EPI schedule for all of them, because each surviving infant should have three doses of pentavalent vaccine.