Part of the low priority given this missile by the USAF was that it already had a guided air-air nuclear missile... the AIM-26A Falcon, in service from 1961 with Air Defense Command F-102s. The AIM-26B had a conventional warhead.
This missile was a larger longer-range version of the AIM-4 Falcon.
The AIM-26A used a .5 kt yield W54 warhead (the same as in the M388 recoilless rifle "Davy Crockett").
The AIR-2 Genie used a 1.5-1.7 kt W25 warhead. It entered service in 1957 with F-86Ds, then F-101Bs in January 1959, and then with F-106s in June 1959.