ADT use may have an immunological benefit during the pandemic

The CDC recommends Covid-19 testing for cancer patients who may be immune-compromised by their cancer or chemo treatment.The extra caution is justified only in men with late-stage PC. Those who have already had prostate radiation, may have some immune enhancement, perhaps especially with SBRT (pre-clinical). The exception may be those who have had whole-pelvic radiation. Assuming that Covid-19 (unlike Spanish Flu) is milder in those with better immune systems, it is possible that ADT may improve their immune response to the disease.

Data are showing that men are dying of Covid-19 at greater rates than women. This may be because of genetic effects and hormonal effects. Testosterone was found to be immunosuppressive for influenza.  ADT has been found to be immunoprotective (here and here).

(UPDATE MAY 26, 2022) Lee et al. reported in an observational study of 3,057 US Veterans using ADT:

ADT is associated with reduced incidence and severity of COVID-19 amongst male Veterans. Testosterone and androgen receptor signaling may confer increased risk for SARS-CoV-2 infection and contribute to severe COVID-19 pathophysiology in men.

Early Covid-19 data are confirming this (here and here)

While normal levels of estrogen seem to be immunoprotective, high levels, as in pregnant women or men on Bipolar Androgen Therapy (because testosterone is metabolized to estradiol), reverses the protection. The implications for ADT use are:

• If you are on continuous ADT, stay on it. This is true even if ADT has been augmented with Zytiga and prednisone, or anti-androgens.Those taking Zytiga with prednisone needn't worry because the prednisone is only a replacement dose, and is not large enough to be immunosupressant. Because of negative feedback, it is more dangerous to take too little prednisone. 
• If you are on intermittent ADT, this might be a good time to end your ADT vacation. 
• Men using Bipolar Androgen Therapy on a clinical trial should discuss the timing with the trial investigator. Anyone taking supraphysiologic doses of testosterone should consider this as well. 
• If you are taking adjuvant ADT after radiation, or neoadjuvant ADT before radiation consider sticking with it a little longer.

(Update 9/23/21) A very small sample size retrospective study found there was no statistically significant difference in Covid-19 death or severity between men who used ADT for PCa  (11 men) and men with PCa and Covid-19 who did not use ADT (80 men).

Also see the recommendations for those getting radiation therapy.