I agree with you that a strong immune system is your best defense. In Stephen Harod Buhner's book, he tells us about some herbs that can be taken to boost the immune system during times when we are more likely to be outside and thus exposed to ticks/Lyme. Astragalus is one of the herbs, would have to re-read the last chapter again for the others.
Chronic Lyme Disease, Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut issues (dysmotility, non-specific inflammation), UCTD ("Secondary Lupus-Like Syndrome"), Osteoporosis, Pancytopenia, chronic malabsorption/malnutrition, etc.; G-Tube; Currently TPN-dependent.
Meds: Zofran, Pulmicort, Heparin (to flush PICC line), IV Ceftazidime (for Pleural Effusion), Colloidal Silver (used topically).