Pfizer-Valneva's Lyme disease vaccine performs even better in children

Pfizer and Valneva’s Lyme disease vaccine worked even better in children than adults, leading the partners to add this population to a late-stage test slated to begin in the third quarter.

In February, Pfizer and Valneva reported that VLA15 was immunogenic in adults after a three-dose series in the phase 2 study called VLA15-221, which built on evidence from earlier studies. The third dose helped add on another layer of protection by increasing the level of antibodies against an outer surface protein.

But now, the partners are seeing the same results in the pediatric population—just better. VLA15 was tested in children as young as 5 and up, comparing immunogenicity after two and three doses. The vaccine was more immunogenic in the pediatric population at either dose than what was seen in adults. Pfizer and Valneva are satisfied with the evidence so far supporting the three-dose schedule.

No vaccine-related serious adverse events were reported and the safety profile was otherwise consistent with the adult population. More details on the study will be presented at a future scientific conference.

Pfizer picked up the rights to VLA15 from Valneva for $130 million upfront in 2020. Valneva already had a pair of mid-stage trials underway when the deal was signed and Pfizer added a third to compare the two- and three-dose schedules.

After the adult data was released, Pfizer and Valneva planned to initiate a phase 3, but the new pediatric data means that population will be included as well. The timeline, subject to regulatory approval, is to get the study going in the third quarter, the companies said.

Back in September 2021, Pfizer and Valneva reported that protection from VLA15 dropped off after 18 months and a booster may be required. The companies are continuing to evaluate this in a subset of patients in the VLA15-221 trial, following them for three additional years.