Novavax’s COVID-19 Vaccine Shows Over 89 Percent Efficacy in Late-Stage Trial

Novavax has announced interim results from a phase 3 UK trial that showed its COVID-19 vaccine candidate, NVX-CoV2373, demonstrated 89.3 percent efficacy but faltered in a separate study that evaluated the vaccine for the South Africa variant.

The analysis of 62 COVID-19 infections in the 15,000-patient phase 3 study found that the vaccine showed high efficacy against both the original SARS-CoV-2 virus and the mutated variant first found in the UK, with more than 50 percent of the infections linked to the variant strain.

But the company also announced early results from a phase 2b study in South Africa, which mostly involved cases of the COVID-19 variant identified in that country. That data showed NVX-CoV2373 had only a 49 percent efficacy in the 4,400-patient trial. For the 94 percent of participants who were HIV-negative, the efficacy increased to 60 percent.

Novavax said that it has now enrolled more than 16,000 participants in a phase 3 trial of the vaccine in the U.S. and Mexico and plans to complete enrollment of 30,000 participants by mid-February. The study is receiving up to $1.75 billion from the U.S. government via Operation Warp Speed.

Novavax’s vaccine began a rolling review process for NVX-CoV2373 with the UK’s Medicines and Healthcare products Regulatory Agency earlier this month. ― Jason Scott