Daily Chart: comparing neutralizing titers from four COVID-19 vaccines in non-human primates
At least four COVID-19 vaccine developers have reported neutralizing titers from immunized non-human primates, with Novavax’s NVX CoV2373 producing at least an order of magnitude higher titers than the other three. However, differing vaccination regimens can make direct comparisons misleading (see “Novavax Announces Neutralizing Titers”).
Clinical trials of all four of the candidates have begun.
Novavax is evaluating two intramuscular immunizations of 5 and 25 μg NVX Cov2373, with and without its Matrix-M adjuvant, in a Phase I trial.
AstraZeneca’s Phase II/III study is assessing one and two immunizations with 5x1010 particles of AZD1222.
A pair of Phase I/II trials is testing two administrations of three doses -- 300, 600 and 1200 SU/mL -- of Sinovac’s CoronaVac.
Sinopharm is testing three administrations of high, medium and low doses of two different inactivated vaccines in the clinic. It is unclear how Sinovac and Sinopharm’s clinical doses compare with those in the non-human primate studies.