Moderna highlights new clinical data on SpikeVax, its COVID-19 vaccine

Moderna, Inc. highlighted a new analysis suggesting that the Moderna COVID-19 vaccine is highly effective against circulating variants of concern , including in a vaccine effectiveness study conducted in partnership with Kaiser Permanente Southern California (KPSC) and in a separate recent publication by the U.S. Centers for Disease Control and Prevention (CDC). Additionally, the Company shared a new analysis of follow-up through 1 year in the Phase III COVE study suggesting a lower risk of breakthrough infection in participants vaccinated more recently (median 8 months after first dose) compared to participants vaccinated last year (median 13 months after first dose). Manuscripts summarizing both findings have been posted to preprint servers and will be submitted for peer-reviewed publication.

Real-World Effectiveness: Prospective Cohort Study at Kaiser Permanente Southern California (follow-up through June 30, 2021): In a prospective cohort study at Kaiser Permanente Southern California (KPSC), an analysis of 352,878 recipients of 2 doses of mRNA-1273 matched to 352,878 unvaccinated individuals found a vaccine effectiveness of 87% (99.3% CI: 85-90%) against COVID-19 diagnosis and 96% (99.3% CI: 91-98%) against COVID-19 hospitalization. The study was conducted during the emergence of the Delta variant, which was identified in 47% of cases in fully vaccinated individuals. These data have been posted to a preprint server and submitted for peer review.

CDC Interim Estimates of COVID-19 Vaccine Effectiveness (June-August 2021): Recent data published by the U.S. CDC examined vaccine efficacy across nine states based on 32,867 medical encounters including 14,636 hospitalizations between June and August 2021, during the time when the Delta variant became predominant in the United States. In the analysis, the Moderna COVID-19 vaccine efficacy against COVID-19 urgent care or emergency visit was 92% (95% CI: 89-93%) and against hospitalization was 95% (95% CI: 92-97%) at a median of 96 and 106 days respectively after vaccination. Across all age groups, vaccine efficacy was reported to be significantly higher among Moderna vaccine recipients than other COVID-19 vaccines.

Analysis of Open-Label Part of Phase III COVE Study (July-August 2021): Today, Moderna is sharing a new analysis of the incidence of breakthrough COVID-19 cases among vaccinated participants in the open-label portion of the Phase III COVE study between July 1, 2021 and August 27, 2021. The goal of the analysis is to quantify the impact of waning immunity in the face of the Delta surge in the United States. The analysis compared participants initially randomized to mRNA-1273 (vaccinated from July-October 2020; n=14,746; median follow-up of 13 months since first dose) against participants initially randomized to placebo who were crossed over and vaccinated following Emergency Use Authorization (vaccinated from December 2020-March 2021; n=11,431; median follow-up of 8 months since first dose).

In the analysis, 88 breakthrough cases of COVID-19 occurred in the more recently vaccinated group (49.0 cases per 1000 person-years) compared to 162 cases in the group vaccinated last year (77.1 cases per 1000 person-years). The reduction in incidence rates for participants vaccinated more recently compared to participants vaccinated last year was 36% (95% CI: 17-52%). A Cox proportional hazards model showed similar results after adjusting for age and risk factors for severe COVID-19. Fortunately, only 19 severe cases were observed. While not significant, there was a numerical trend towards a lower rate of severe cases in the group vaccinated more recently (3.3 per 1000 person-years) compared to the group vaccinated last year (6.2 per 1000 person-years). The increased risk of breakthrough in this analysis quantifies the impact of waning immunity in the COVE study between the median follow-up time of 8 months and 13 months since first dose. The Company believes this adds to evidence of potential benefit of a booster dose of mRNA-1273. A manuscript has been submitted as a preprint to medRxiv and will be submitted for peer-reviewed publication.