Pfiz­er and Val­ne­va say sec­ond Ly­me boost­er led to 'strong' re­spons­es, tar­get 2026 FDA sub­mis­sion

Pfiz­er and Val­ne­va said pa­tients demon­strat­ed “strong im­mune re­spons­es” af­ter re­ceiv­ing a sec­ond boost­er dose of their ex­per­i­men­tal Ly­me dis­ease vac­cine, sup­port­ing the case for an­nu­al dos­ing.

Pa­tients in a Phase 2 tri­al were giv­en a sec­ond boost­er dose of the pro­tein-based vac­cine VLA15 one year af­ter re­ceiv­ing their first boost­er. At a one-month fol­low-up, they showed sim­i­lar im­mune and safe­ty re­spons­es to those ob­served af­ter the first boost­er.

Val­ne­va CEO Thomas Lin­gel­bach has pre­vi­ous­ly hy­poth­e­sized that an an­nu­al boost­er will be re­quired to pro­tect pa­tients, and the com­pa­nies said Tues­day that the lat­est Phase 2 da­ta show “com­pat­i­bil­i­ty” with that the­o­ry.

Juan Car­los Jaramil­lo

“We are en­cour­aged by these da­ta, which sup­port the po­ten­tial ben­e­fit of boost­er dos­es across all ex­am­ined age groups,” Val­ne­va med­ical chief Juan Car­los Jaramil­lo said in a news re­lease.

The re­sults showed “sig­nif­i­cant anamnes­tic an­ti­body re­sponse” across all six serotypes cov­ered by the vac­cine across three age groups, rang­ing from 5 to 65 years old. Pfiz­er and Val­ne­va re­port­ed se­ro­con­ver­sion rates — which mea­sure the de­vel­op­ment of an­ti­bod­ies in re­sponse to a vac­cine — above 90% for all out­er-sur­face pro­tein A serotypes in all age groups, in line with re­spons­es seen af­ter the first boost­er dose.

Eu­gene Shapiro, a Yale Uni­ver­si­ty pro­fes­sor of pe­di­atrics and epi­demi­ol­o­gy, told End­points News on Tues­day that the da­ta aren’t sur­pris­ing.

“How­ev­er, the key is­sue is the ac­tu­al clin­i­cal ef­fi­ca­cy of the vac­cine, which will be de­ter­mined in the piv­otal Phase 3 clin­i­cal tri­al, which is cur­rent­ly on­go­ing,” Shapiro said.

Pfiz­er put down $130 mil­lion up­front in 2020 to part­ner with Val­ne­va on VLA15. The can­di­date tar­gets a sur­face pro­tein on the bac­te­ria that cause Ly­me dis­ease, in the hopes of pre­vent­ing the bac­te­ria from leav­ing ticks and in­fect­ing hu­mans. It’s cur­rent­ly in two Phase 3 tri­als, one of which is ex­pect­ed to read out by the end of 2025, Val­ne­va said last month. The sec­ond Phase 3 is de­signed to col­lect fur­ther safe­ty da­ta in the pe­di­atric pop­u­la­tion.

Pfiz­er hopes to file for ap­proval in 2026, “sub­ject to pos­i­tive Phase 3 da­ta,” the com­pa­ny said.