---
title: "Key facts: Merck (MRK) up on vaccine; policy may hit M-M-R II, ProQuad"
type: "News"
locale: "en"
url: "https://longbridge.com/en/news/296749142.md"
description: "Merck (MRK) saw a sharp one-day stock move after positive late-stage trial results: adding a personalized mRNA melanoma vaccine to Keytruda cut recurrence versus Keytruda alone. Dow Jones NewswiresMerck (MRK) said proposed vaccine policy shifts could affect its M-M-R II and ProQuad, noting a move toward separate measles, mumps and rubella shots and related schedule reviews. BenzingaDisclaimerThis is an AI-generated summary and may contain inaccuracies. Please verify any important information with the original sources."
datetime: "2026-08-24T07:14:12.000Z"
locales:
  - [zh-CN](https://longbridge.com/zh-CN/news/296749142.md)
  - [en](https://longbridge.com/en/news/296749142.md)
  - [zh-HK](https://longbridge.com/zh-HK/news/296749142.md)
generator: "portal-rs"
---

# Key facts: Merck (MRK) up on vaccine; policy may hit M-M-R II, ProQuad

-   Merck (MRK) saw a sharp one-day stock move after positive late-stage trial results: adding a personalized mRNA melanoma vaccine to Keytruda cut recurrence versus Keytruda alone. Dow Jones Newswires
-   Merck (MRK) said proposed vaccine policy shifts could affect its M-M-R II and ProQuad, noting a move toward separate measles, mumps and rubella shots and related schedule reviews. Benzinga

**Disclaimer**

This is an AI-generated summary and may contain inaccuracies. Please verify any important information with the original sources.

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---
> **Disclaimer: This article is for reference only and does not constitute any investment advice.**