@golfbarmie, some of your questions regarding prednisone and vaccine efficacy were answered in a recent Q&A with Mayo Clinic's Dr. Gregory Poland, an infectious diseases specialist.

Watch the video to hear his answers to these questions:
Q: 4:52 Should people who are immunocompromised or have immune diseases be vaccinated?
Q: 6:12 For the immunocompromised should they be tested for antibodies to make sure that their
vaccine was effective?
Q: 6:47 Should those with immunosuppressants should they take medicines like Prednisone?

- Rapid pace of COVID-19 (3/15/2021) vaccinations https://connect.mayoclinic.org/blog/podcasts/newsfeed-post/rapid-pace-of-covid-19-vaccinations/

Also see these related questions and answers in this video.

Q: 4:05 What are normal reactions to the vaccines? How do I know that my reactions are
normal? How do I know what to do about it?
Q: 7:05 How do you know the difference between what is an immune response, which is what
we want, and what is an allergic response?
Q: Does the second dose promote more of a reaction or are we getting something different? Why
do we react differently?
Q: 10:20 How do you explain not having a response or a very mild response?

Tackling the Latest about Covid-19 (2/16/2021) https://connect.mayoclinic.org/blog/podcasts/newsfeed-post/tackling-the-latest-covid-19-topics/