What are the main criteria used by the European Commission to compute the COVID-19 vaccines to be received by the member state?

Question

I have recently seen an interview with a Romanian State Secretary at Health Ministry about the COVID-19 vaccination. The interview touched on the sensitive point of insufficient vaccine doses and the reporters asked about how the actual doses Romania receives are actually computed.

There was no direct answer, but an educated guess that the algorithm is not clear and most certainly is heavily influenced by member state population size and infection incidence rate. This last factor is particularly sensitive for Romania, due to a rather small amount of tests being performed.

This document suggests that the population size is the major (only?) factor, but the final distribution is not clear:

Agreements contain a provision on the equal distribution of vaccine doses to the Member States, which will ensure that each country receives doses based on a pro-rata population distribution key, unless otherwise agreed between the participating Member States in the course of implementation of the Advance Purchase Agreements

Is the European Commission algorithm (used to compute vaccine doses to be received by each country) public?

A very similar question was posted here (thanks Hulk for providing this reference).

Answer 1

Written questions from MEPs to the European Commission on this topic from October & November were answered by Stella Kyriakides, the EU Commissioner for Health and Food Safety, in February (1) (2) with the following line regarding the distribution key:

In line with the EU vaccine strategy agreed with Member States, once authorised and produced, each vaccine will be available to Member States at the same time based on population size.

This was not necessarily the case. The partially redacted advance purchase agreement (APA) between the European Commission and AstraZeneca published at the end of January contains the following provision:

8.3. Allocation.

• (a) No later than REDACTED following the Effective Date, the Commission shall deliver to AstraZeneca a final and binding written allocation of Initial Europe Doses between the Participating Member States (the “Binding Allocation”), which Initial Europe Doses must equal 300 million. The number of Initial Europe Doses set forth in the Binding Allocation shall be the total number of Initial Europe Doses that each Participating Member State is required to purchase pursuant to this Agreement.
• (b) In the event that the Commission does not provide a Binding Allocation within the REDACTED period or the number of Doses set forth in the Binding Allocation does not equal 300 million, then, unless otherwise agreed in writing by the Commission and AstraZeneca, the binding allocation of the Initial Europe Doses shall be made on a pro-rata basis to reflect the respective populations of each of the Participating Member States utilizing the population estimate as of 10 July 2020 reported by the statistical office of the European Union, Eurostat. In the event there is an excess of supply of the Initial Europe Doses and Optional Doses, the Participating Member States shall keep their shared rights in the Initial Europe Doses, and shall determine their best use of such excess doses, reserving the possibility to donate them to lower or middle income countries or public institutions and to donate or resell, at no profit, such doses to other European countries that agree to be bound by the terms and conditions of this Agreement applicable to a Participating Member State.
• (c) The Participating Member States may also resell, at no profit, Initial Europe Doses and/or Optional Doses to European countries that are not Member States if such other European countries agree to be bound by the terms and conditions of this Agreement applicable to a Participating Member State. Should such resale take place, the Participating Member States concerned shall reimburse the Commission the part corresponding to the Initial Funding in accordance with Sections 7.2 and 7.4(a).

So by the terms of the AstraZeneca contract - and presumably APAs agreed with other vaccine manufacturers - the European Commission reserved the right for some unknown period following the 'Effective Date' (27 August 2020) to provide a 'Binding Allocation' which could have differed from the pro-rata population distribution key. I think we can safely assume given the response to the written questions above that at this point the period has expired, meaning that the Initial Europe Doses are being distributed on the basis of population according to Eurostat's figures published here.