None of the approved vaccines have produced T-cell (long term) immunity ... zip .. zero ... zilch ... nada ... bupkis. Pfizer CEO said we will need another vaccine ... will it be the "Complete Vaccine"? ... Bintai and China are placing there bets ... there is no other game in town for at least ex-vivo proof of long term immunity (although I can't quite find a definitive answer in NVAX produces long term immunity). Current vaccine boosters will be needed again and again ... every 8 months? Who knows. And the Merck drug is not a rock solid solution ... makes sense for them to keep some skin in the game ... I'm sure they talk to Joe and get the real scuttlebutt ...