Do you utilize post-vaccination IgG titers to detect common variable immunodeficiency in patients who are about to start or are actively on B cell depleting therapy?

I have checked M-M-R, Td, and pneumococcal titers in patients with hx of infection and low Ig levels to see if they are making an immunological response. If any of these immune titers are low or the immunization is “due” by routine schedules, I recommend immunization and repeat testing in 6 weeks. The most common one (all comers, all age groups) is tetanus since there is an indication to immunize once the patient passes 10 years from the last immunization. I have accomplished this by referring b...

I do check a VZV titer before starting a B cell therapy and if low, I advise patients to start the Shingrex series. I don't typically check titers once therapy has started if testing was normal prior to initiation.