Thread by @Novavax

NEWS: Novavax Announces #COVID19 Vaccine Booster Data Demonstrating Four-Fold Increase in Neutralizing Antibody Levels Versus Peak Responses After Primary Vaccination ir.novavax.com/2021-08-05-Nov…

Following the primary vaccination series (21 days apart), a single booster dose at 6 months of NVX-CoV2373 induced a robust increase in anti-Spike antibody levels - up ~4.6-fold vs the response seen after the primary series.

The increased antibody response was consistent for both younger and older adults.

Our #clinicaltrials in the UK and US/Mexico (PREVENT-19) showed high levels of vaccine efficacy. After a 3rd booster dose, antibody responses were ~4x greater than observed in those Phase 3 studies.

We also report boosted microneutralization responses that were ~5x greater than those observed in Phase 3 studies.

A 3rd dose boost increased functional hACE2 inhibition responses against variants. Response vs Delta (B.1.617.2) variant was >6x higher than after the primary series, >10x for Beta (B.1.351) & >8x for Alpha (B.1.17)

This post-boost consistency suggests a maturation of the immune response.

A third dose was generally well tolerated. Local & systemic symptoms showed a favorable, consistent reactogenicity profile. 90% of symptoms rated as mild or moderate after the third dose.

Adverse events were balanced between vaccine and placebo groups, with low rates of severe and adverse events.

ICYMI, we previously reported on the co-administration of NVX-CoV2373 with seasonal #flu #vaccine. Giving both #COVID19 & seasonal #influenza vaccines was generally well-tolerated: medrxiv.org/content/10.110…

Further, immune responses were not significantly changed when both #COVID and #flu vaccines were given, suggesting they can be used together in an annual vaccination campaign.

Together, this new data support the use of our NVX-CoV2373 vaccine in a boosting campaign. See the full presentation and learn more: ir.novavax.com/image/Q2-2021-…