2) There are some real concerns regarding systemic corticosteroid effects, but they mostly apply when getting shots and (I think) tablets. Inhaled budesonide has a much shorter half life and reduced bio availability, so there is much less reason for concern.
Thanks! Would you be willing to give a little context on how you reached your conclusion?
Symbicort is solely a inhaled drug, as far as I can tell, so I believe the drugs.com reference would apply to that, unfortunately.
Anyone have insight on (1) Whether there is a way to test how effective an immune response you had to the vaccine or (2) the extent to which inhaled glucocorticoids (specifically Symbicort) impact the effectiveness of the mRNA COVID vaccines (specifically Pfizer)?
On (1) there doesn't seem to be any useful test commercially available.
On (2): It seems inhaled corticosteroids should be fine:
The AAAAI emphatically says: "No, there is no impact on an individual’s ability to respond to the vaccine and control of asthma is essential! There is no data to suggest that inhaled corticosteroids and/or leukotriene receptor antagonists impact on immunogenicity of the mRNA COVID-19 vaccines."
(They seem to avoid the error of assuming that no evidence = no impact: they use different language when discussing another question on which "no information could be found and more information is needed" suggesting that they are not simply saying, "oh there are no studies on this so it's not a problem." They also seem to be speaking pretty specifically about Symbicort in that answer, since later they say "Daily oral steroids may interfere with the antibody response to the vaccine based on data with other immunosuppressives and flu vaccine.") (https://education.aaaai.org/resources-for-a-i-clinicians/vaccines-qa_COVID-19)
Drugs.com somewhat confusingly says otherwise...
However, drugs.com says there are moderate interactions between Symbicort and the Pfizer COVID vaccine: "If you are currently being treated or have recently been treated with budesonide, you should let your doctor know before receiving SARS-CoV-2 (COVID-19) mRNA BNT-162b2 vaccine. Depending on the dose and length of time you have been on budesonide, you may have a reduced response to the vaccine. In some situations, your doctor may want to delay vaccination to give your body time to recover from the effects of budesonide therapy. If you have recently been vaccinated with SARS-CoV-2 (COVID-19) mRNA BNT-162b2 vaccine, your doctor may choose to postpone treatment with budesonide for a couple of weeks or more
"... For SARS-CoV-2 (COVID-19) vaccines, vaccination should preferably be completed at least two weeks before initiation of immunosuppressive therapies; however, decisions to delay immunosuppressive therapy to complete COVID-19 vaccination should consider the individual's risks related to their underlying condition. Vaccines may generally be administered to patients receiving corticosteroids as replacement therapy (e.g., for Addison's disease)."
(https://www.drugs.com/interactions-check.php?drug_list=432-2530,4221-19642)
...but there's good reason to believe Symbicort is still fine: