TheVoiceOfJoyce Not yet approved for use in USA , the Astra Zeneca/Oxford collaboration is now being used in several countries. A lucky accident cuts the first dosage in half and the booster is given 28 days later. Efficacy has been resolved and it requires simple refrigeration for 6 months. It’s also cost effective @$3-4 a shot. It works by activating your T cell &B cell responses, similar to monoclonal antibody therapy. Sounds promising. May have long lasting immunity.