PFE: Impressive Serotype 3 Immunogenicity Data for Prevnar 25, But Await Additional Details to Assess Longer-Term Impact

Research evidence excerpt

PFE: Impressive Serotype 3 Immunogenicity Data for Prevnar 25, But Await Additional Details to Assess Longer-Term Impact

FLASH NOTE

May 20, 2026

Vamil Divan, M.D. vamil.divan@guggenheimpartners.com PFE: Impressive Serotype 3 Immunogenicity Data for

212 823 6543 Prevnar 25, But Await Additional Details to Assess

Daniel Krizay, Ph.D.

daniel.krizay@guggenheimpartners.com Longer-Term Impact

212 823 6561

Arseniy Shabashvili Key Message: Pfizer presented Phase 2 data from their 25-valent pneumococcal

arseniy.shabashvili@guggenheimpartners.com vaccine candidate PF-07872412 at the ISPPD Conference this morning. Most notably, 212 699 1971

in a pediatric population and as compared to what was seen with Prevnar 20, the

Edouard Mullarky, Ph.D. vaccine led to 8.8x higher geometric mean titers for serotype 3 one month after Dose

edouard.mullarky@guggenheimpartners.com 3 and about 15x higher titers one month after Dose 4 (Fig. 2). Based on our review of

212 518 9579 the presentations (please let us know if you would like us to send you copies of the

presentations) it does not appear that PFE presented any data on other serotypes, but

the company states strong immune responses were observed for all serotypes in the trial

PFE andprogram.is confidentPfizer believesthe requiredthe vaccinenon-inferioritycould providethresholdsprotectionmay be forachievedup to 90%for theof disease-Phase 3

Pfizer Inc. causing serotypes in children under 5 years of age. While we wait for additional details

Sector: Global Biopharmaceuticals on other serotypes, we find this data encouraging as the company works to protect

its important Prevnar franchise, which generated sales of $6.5Bn in 2025. Additionally,

Company Update Pfizer continues to advance their 35-valent PCV candidate in the adult population, with