Update on Lyme diseases vaccine

The first modern Lyme vaccine, LYMErix, was an OspA-based recombinant subunit vaccine that showed good efficacy and acceptable safety in phase III trials but ultimately failed due to a confluence of scientific, regulatory, commercial, and sociopolitical factors. ImuLyme, a second OspA-based candidate, also demonstrated high efficacy but was never licensed because of perceived market and legal risks. Experience with the first Lyme vaccine (Poland 2011) Poland describes how LYMErix (SmithKline Beecham/GSK) and ImuLyme (Pasteur Merieux Connaught) emerged from the concept of “transmission‑blocking” vaccination: human anti‑OspA antibodies ingested by feeding ticks cleared Borrelia from the tick midgut before transmission. In the pivotal LYMErix phase III trial (n≈10,900, adults 15–70 years), a three‑dose 0‑1‑12‑month schedule yielded ~76% efficacy against definite symptomatic Lyme disease after three doses and 49% after two doses; efficacy against asymptomatic infection was even higher, reaching 100% after three doses, albeit with wide confidence intervals. Local and systemic reactogenicity was modestly...