AstraZeneca (AZ) has published updated results from a US-based trial of its COVID-19 vaccine, after receiving criticism that initial data published earlier this week may have included ‘outdated information’.
On Monday, AZ said that its vaccine demonstrated 79% efficacy in the US trial, following a pre-specified interim analysis of the data, which had a cut-off of 17 February.
Following this, the US National Institute of Allergy and Infectious Diseases (NIAID) issued a statement saying that the trial’s data and safety monitoring board (DSMB) had expressed concerns about the initial data from AZ’s COVID-19 vaccine trial.
The DSMB expressed concerns that AZ may have included outdated information from the trial, which could have provided an ‘incomplete’ image of the efficacy data.
In response, AZ said it would ‘immediately’ engage with the DSMB to share the primary analysis with the up-to-date efficacy data.
The primary analysis demonstrated at 76% efficacy at preventing symptomatic COVID-19 – slightly lower than the previously reported 79% – although the updated results showed the vaccine was consistent at preventing severe or critical disease and hospitalisation, demonstrating 100% efficacy on this marker.
The updated results were comparable across age groups, with vaccine efficacy of 85% in adults aged 65 years and older.
“The primary analysis is consistent with our previously released interim analysis, and confirms that our COVID-19 vaccine is highly effective in adults, including those aged 65 years and over,” said Mene Pangalos, executive vice president, BioPharmaceuticals R&D, AZ.
“We look forward to filing our regulatory submission for emergency use authorisation in the US and preparing for the rollout of millions of doses across America,” he added.