South Africa COVID vaccine results cause Novavax to begin work immediately on ”a booster and/or combination bivalent vaccine”

Today the U.S.-based Novavax announced the results in a press release that its COVID-19 vaccine had 49.4% vaccine efficacy (95% Confidence Interval: 6.1 – 72.8) in its overall trial population in a Phase 2b trial in South Africa. Novavax stated that “approximately 90% of COVID-19 cases attributed to South Africa escape variant” (501Y.V2). The immediate implication for vaccine development was also addressed (my boldtype added):

“Novavax initiated development of new constructs against the emerging strains in early January and expects to select ideal candidates for a booster and/or combination bivalent vaccine for the new strains in the coming days. The company plans to initiate clinical testing of these new vaccines in the second quarter of this year.”

The need to develop bivalent vaccines was advocated here Jan. 26, including the variant 501Y.V2 first found in South Africa.

In the same press release Novavax reported results from its United Kingdom trials of a vaccine efficacy of 89.3% (CI: 75.2095.4). Notably, Novavax also stated that: “Based on PCR performed on strains from 56 of the 62 cases, efficacy by strain was calculated to be 95.6% against the original COVID-19 strain and 85.6% against the UK variant strain [post hoc]."

In the meantime, the first two persons in the U.S. infected with the variant 501Y.V2 found initially in South Africa, were reported today.