I have anti-MuSK MG, treated with rituximab 1,000 mg. infusion every 6 months. I got the Moderna vaccines (two doses) in Feb. 2021, received my rituximab infusion in May, and then in June 2021, when tested, I had no antibodies to SARS-CoV-2. My immunologist felt that boosters were a waste of time and vaccine because of the effects of the rituximab. At the time, my only option was to isolate (or be masked and careful when out). After Evusheld was released in January, my immunologist wrote me a script. I had to get on a waiting list. When they called me, the nearest site was over an hour drive away, but I opted for it. They gave me a double dose (4 vials IM which is standard for the first dose) on March 18th. I had no symptoms after the administration. We haven’t drawn antibodies yet to see if I have generated any. I understand that I will need to return every 6 months for the Evusheld. Keeping my fingers crossed. Hope this information helps.