Summary
Cosmos data suggests the JYNNEOS vaccine is effective at reducing the risk of mpox disease, with two doses providing the best protection, regardless of how the vaccine was administered.
Epic Research partnered with Centers for Disease Control and Prevention (CDC) to investigate the effectiveness of the JYNNEOS vaccine at reducing the risk of mpox disease that requires medical attention. Using real-world evidence from Cosmos, we matched patients with an mpox diagnosis or positive lab result to patients with an incident HIV diagnosis or HIV pre-exposure prophylaxis (PrEP) prescription to evaluate the effectiveness of the JYNNEOS vaccine. Cases and controls were matched on the week of the index event, HHS region, and gender identity.
We found a single dose and the full two dose series reduced the risk of mpox disease, with two doses providing the best protection; vaccine effectiveness was 69% for the full two dose series and 37% for a single dose.

This data was originally shared on the CDC’s website.