Questions linger on the efficacy of the Lyme disease vaccine
A new study examines the efficacy of the Borrelia burgdorferi outer surface protein A (OspA) vaccine in a meta-analysis. 
by Daniel J. Cameron, MD MPH
The OspA vaccine trial was 78% effective at preventing a culture confirmed erythema migrans rash. But the vaccine was only 48% effective at preventing what the authors referred to as “possible Lyme disease.”
“Possible Lyme disease was defined as a flu-like illness (fever, chills, fatigue, headache, joint or muscle aches) with IgM or IgG Western blot seroconversion, or physician-diagnosed erythema migrans with negative laboratory results,” according to the LYMErixTM package insert. 
The vaccine trial did not address whether their OspA vaccine would prevent other complications of Lyme disease including Lyme encephalopathy or Post-Treatment Lyme Disease Syndrome.
- The OspA vaccine raised other efficacy issues that were not addressed in the meta-analysis. 
- The OspA vaccine was minimally effective in subjects vaccinated only twice. 
- The efficacy of the OspA vaccine beyond the second year was unresolved. 
- The OspA was not evaluated for the B. garinii and B. afzelii genospecies described in Europe. 
- Moreover, the potential for autoimmunity due to molecular mimicry was not addressed. 
It would be helpful if these lingering questions were resolved. The meta-analysis concluded that a new-generation, multivalent OspA-based Lyme borreliosis vaccine might be more effective against all Borrelia burgdorferi sensu lato strains.
- Zhao H, Bao FF, Liu A: Safety, immunogenicity, and efficacy of Borrelia burgdorferi outer surface protein A (OspA) vaccine: A meta-analysis. J Infect Dev Ctries 2017, 11(1):1-9.
- FDA Package Insert – LYMErixTM
- Steere AC, Sikand VK, Meurice F, Parenti DL, Fikrig E, Schoen RT, Nowakowski J, Schmid CH, Laukamp S, Buscarino C et al: Vaccination against Lyme disease with recombinant Borrelia burgdorferi outer-surface lipoprotein A with adjuvant. Lyme Disease Vaccine Study Group. N
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