Moderna Covid Vaccine Effectiveness After 8 Months. Its vaccine protection wanes by 36% after 12 months, according to a new study by alice park september 16, 2021 8:42 am edt But over the next six months, that changed dramatically.
In this new effort, the researchers sought to find out if the same. After four months, moderna's vaccine remained 92% effective at preventing hospitalization, while pfizer's was 77% effective and j&j's was 68%. Vaccine effectiveness (%) ≥ 65 years of age.