Moderna shares gained 18% last week-finishing it at their highest level in more than four years-after the New York Times reported Friday that the National Institutes of Health is planning a public-private effort to speed up cancer vaccines. Moderna stock also joined the Nasdaq-100 index, replacing Warner Bros. Discovery after its acquisition by Paramount Skydance.

The vaccine maker's stock has been a star performer this year, rising more than 600% and revisiting levels closer to its pandemic-era high. Shares took off anew in August, when Moderna and Merck said that their personalized mRNA cancer vaccine delayed the return or spread of cancer in a Phase 3 trial of certain melanoma patients. The companies plan to release full data later this month, and are preparing for regulatory approval of the medication next year.

Merck shares rose 2.3% on Friday. U.S.-traded shares of BioNTech, which is developing similar vaccines for pancreatic cancer, rose more than 5%. Novavax, which currently makes vaccines for infectious diseases but is exploring the possibility of cancer vaccines, climbed 16%.