The surplus doses tool calculates the potential number of doses remaining from a country's purchase agreements, once they have vaccinated their populations, with the option of including boosters and alternative scenarios in the analysis. We can then see what these surpluses will be at the end of 2021 and 2022.
These surpluses can be further split amongst a country’s supplied vaccines, to get an idea of which specific vaccines a country might have a surplus of. The tool provides several scenarios to the user, all of which can be combined:
Specify the age range of individuals receiving doses
Specify the percentage of the specified population required to be vaccinated before doses are determined to be “surplus”
Booster shots can be allowed for before we consider subsequent supply as surplus
Hypothetical donations can be taken into account
Expiration dates for vaccines can also be taken into account