I'd like to know if your immune system will recover from chemotherapy, say, after x years, or will your immune system forever be weakened/compromised from chemotherapy?
This must depend on the type of chemotherapy, and duration of treatment.
This study looked at lymphocyte populations after chemotherapy for breast cancer and found
RESULTS: Levels of B, T and NK cells were significantly reduced 2 weeks after chemotherapy (p < 0.001). B cells demonstrated particularly dramatic depletion, falling to 5.4 % of pre-chemotherapy levels. Levels of all cells recovered to some extent, although B and CD4(+) T cells remained significantly depleted even 9 months post-chemotherapy (p < 0.001). Phenotypes of repopulating B and CD4(+) T cells were significantly different from, and showed no sign of returning to pre-chemotherapy profiles. Repopulating B cells were highly depleted in memory cells, with proportions of memory cells falling from 38 % to 10 % (p < 0.001). Conversely, repopulating CD4(+) T cells were enriched in memory cells, which increased from 63 % to 75 % (p < 0.001). Differences in chemotherapy regimen and patient smoking were associated with significant differences in depletion extent or repopulation dynamics. Titres of anti-pneumococcal and anti-tetanus antibodies were both significantly reduced post-chemotherapy and did not recover during the study (p < 0.001).
and concluded that
CONCLUSION: Breast cancer chemotherapy is associated with long-term changes in immune parameters that should be considered during clinical management.
However, the significance of these findings is still unclear.
Lymphocyte depletion and repopulation after chemotherapy for primary breast cancer 2016 full text