The 31 countries targeted and responses obtained
| Country | Population millions# | Adult | Paediatric |
| Austria | 8.60 | • | |
| Belgium | 11.20 | • | |
| Bulgaria | 7.20 | ||
| Croatia | 4.20 | • | • |
| Cyprus | 0.80 | ||
| Czech Republic | 10.50 | • | • |
| Denmark | 5.70 | • | • |
| Estonia | 1.30 | • | • |
| Finland | 5.50 | ||
| France | 66.40 | • | • |
| Germany | 81.10 | • | |
| Greece | 10.90 | • | • |
| Hungary | 9.90 | • | |
| Ireland | 4.60 | • | • |
| Iceland | 0.35 | ||
| Italy | 60.80 | • | • |
| Latvia | 2.00 | ||
| Lithuania | 2.90 | • | • |
| Luxembourg | 0.60 | ||
| Malta | 0.40 | • | |
| Netherlands | 16.90 | • | • |
| Norway | 5.30 | • | • |
| Poland | 38.00 | ||
| Portugal | 10.30 | • | |
| Romania | 19.80 | • | • |
| Slovakia | 5.40 | ||
| Slovenia | 2.10 | ||
| Spain | 46.40 | • | |
| Sweden | 9.70 | • | |
| Switzerland | 8.50 | • | • |
| UK | 66.40 | • | • |
| Total | 523.80 | 19 | 17 |
#: derived from European Union and national sources [11–13].