I thought you would be interested in this article about how effective the SHingrix vaccine is, even when you are on corticosteroids.
medscape.com/viewarticle/sh...
"... people who received two doses of the vaccine, regardless of when they received their second dose, experienced 79% vaccine effectiveness (VE) during the first year, with effectiveness decreasing to 73% by year 4. By contrast, the rate of effectiveness during the first year was 70% for people who received a single dose, falling to 52% effectiveness by year 4.
The findings also showed that the rate of effectiveness was 65% for those taking corticosteroids.
The CDC currently recommends two doses of RZV separated by 2-6 months for patients aged 50 years and older. Adults older than 19 years who are immunocompromised should receive two doses of RZV separated by 1-2 months,"
Other longerterm studies show that it is still effective after 7 years.