People re-infected with Lyme disease may develop strain-specific immunity
Have you ever wondered whether an infection with the Lyme disease (LD) spirochete elicits protective immunity? Izac and Marconi addressed that question in a recent study. The authors examined mice infected with clonal populations of spirochetes to determine if broad or strain-specific, bactericidal antibody responses occurred. 
by Daniel J. Cameron, MD, MPH
“It is common knowledge among veterinarians who practice in LD endemic areas that a significant percentage of dogs will develop repeated LD infections,” writes Khatchikian in the journal Infection and Immunity. 
“This phenomenon is well-documented in humans,” as well, explains Khatchikian. “In one study, 15% of patients with LD living in a Lyme endemic area developed 1 or more follow-up infections within five years.”Re-infection with the Lyme disease bacteria may trigger an immunity to that specific strain of Borrelia burgdorferi. Click To Tweet
“Many patients treated for early Lyme disease incur another infection in subsequent years, suggesting that previous exposure to Borrelia burgdorferi may not elicit a protective immune response,” Khatchikian writes.
“However, identical strains are almost never detected from patients who have been infected multiple times, suggesting that B. burgdorferi exposure may elicit strain-specific immunity.” 
- Izac JR, Marconi RT. Diversity of the Lyme Disease Spirochetes and its Influence on Immune Responses to Infection and Vaccination. Vet Clin North Am Small Anim Pract. 2019.
- Khatchikian CE, Nadelman RB, Nowakowski J, Schwartz I, Wormser GP, Brisson D. Evidence for strain-specific immunity in patients treated for early lyme disease. Infect Immun. 2014;82(4):1408-1413.
- Nowakowski J, Nadelman RB, Sell R, et al. Long-term follow-up of patients with culture-confirmed Lyme disease. Am J Med. 2003;115(2):91-96.