Oxford says vaccine has good immune response with two-dose regimen

By Reuters Staff

LONDON (Reuters) – Oxford’s COVID-19 vaccine candidate has a better immune response when a two full-dose regimen is used rather than a full-dose followed by a half-dose booster, the university said on Thursday.

The vaccine candidate, which has been licensed to AstraZeneca, previously published interim late stage trial results showing higher efficacy when a half dose was followed by a full dose, compared to a two full-dose regimen, though more work needs to be done to affirm the result.

The subgroup details from the Phase I/II clinical trials released on Thursday made no reference to the half-dose/full-dose regimen, which Oxford has said had been “unplanned” but approved by regulators.

The university said it had explored two dosing regimens in early stage trials, a full-dose/full-dose regimen and a full-dose/half-dose regimen, investigated as a possible “dose sparing” strategy.

“The booster doses of the vaccine are both shown to induce stronger antibody responses than a single dose, the standard dose/standard dose inducing the best response,” the university said in a statement.

The vaccine “stimulates broad antibody and T cell functions,” it noted. In addition to the university statement, the new interim results were published on Thursday in Nature Medicine (https://go.nature.com/37rw61r).