Dear Agatha,
If I remember it correctly, US Employer Identification Numbers cannot be issued by the IRS in the United States for foreign government-owned organisations, since that would amount to one country paying taxes to another country (wars have been started for lesser reasons...). For this reason, and in order to have an applicant organization identifier, the NIH issues its own EIN numbers for foreign institutions; those are the ones that ends with an "A1", but they can only be used towards the NIH, not in any other situation (including other federal funders).
If ETH has both kinds of numbers, I would ask the prime awardee, and if they cannot answer, try to get in touch with NIH's OER.
Please be aware that I am writing this out of my memory, so it should be checked first.
Have a pleasant weekend, with or without EIN's...
Olaf
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Olaf Svenningsen
Head of Research Support Office\/ Chair of DARMA
University of Southern Denmark
DK-5000 Odense C
456-550-3374
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