Moderna shares slide as longer-term data shows quick fall in RSV vaccine efficacy

By Thomson Reuters Feb 9, 2024 | 9:28 AM

(Reuters) – Moderna shares fell 6% on Friday after a longer-term analysis of a trial indicated a quicker fall in the efficacy of its experimental respiratory syncytial virus (RSV) vaccine.

At least two analysts pointed to the data, posted ahead of a conference on RSV next week, that showed a vaccine efficacy of about 63% after 8.6 months, from 84% at 3.3 months.

Pfizer’s vaccine efficacy went from 67% to 49% in 17 months, while GSK’s fell to 77% at 14 months from 83%, TD Cowen analyst Tyler Van Buren said.

The data suggests Moderna’s RSV vaccine efficacy is “declining quicker than the GSK and Pfizer vaccines,” he said.

Moderna’s shares were at $88 in morning trading, and were on track for their biggest one-day fall since November.

(Reporting by Manas Mishra in Bengaluru; Editing by Sriraj Kalluvila)