AstraZeneca Vaccine Re-Tests Confirm Original Efficacy

The company may have expected US approval to be a foregone conclusion, especially since the country is unlikely to need any of that vaccine as it has more than enough to inoculate its entire population using Moderna, Pfizer and J&J, so it may have been less scrupulous in its presentation than it should have. 

But the combination of disturbing side effects and logistical miscues in European countries caused regulatory authorities in the EU and US to demand even greater assurance. The lesson learned is that in the midst of a pandemic in the internet era, everyone is a data scientist. JL

Jenny Strasburg and Joseph Walker report in the Wall Street Journal:

The drugmaker had drawn fire earlier this week after it had provided preliminary data from the trial indicating its vaccine was 79% effective in 141 subjects. Its latest figure on the vaccine’s efficacy was based on an analysis of 190 cases of symptomatic Covid-19 in the trial, 49 more cases than the company had analyzed earlier. The vaccine’s performance was in line with what AstraZeneca had first reported: the shot was 76% effective at preventing Covid-19 with symptoms. The preliminary results indicated that the vaccine was even more effective in subjects ages 65 years and older and that the shot was safe.

AstraZeneca AZN -0.24% PLC released more pivotal-trial data for its Covid-19 vaccine, saying the shot was 76% effective at preventing Covid-19 with symptoms in a fuller analysis of study results than the company had earlier provided.

AstraZeneca said its latest figure on the vaccine’s efficacy was based on an analysis of 190 cases of symptomatic Covid-19 in the trial, 49 more cases than the company had analyzed earlier.

Despite the additional cases, the vaccine’s performance was in line with what AstraZeneca had first reported.

The London-based drugmaker had drawn fire earlier this week after it had provided preliminary data from the trial indicating its vaccine was 79% effective in 141 subjects.

An independent study-monitoring board said the data were out of date, prompting the U.S. National Institute of Allergy and Infectious Diseases to issue an unusual statement raising the experts’ concerns.

The tempest added to the clouds that have hovered over the shot, which AstraZeneca developed in partnership with the University of Oxford.

Its rollout has been marred by a series of missteps including how the partners communicated earlier U.K. trial results. They presented a confusing array of dosing sizes and schedules, a wide range of efficacy results and few elderly trial subjects.

In Europe, AstraZeneca has fallen far short of supply targets, prompting fierce condemnation from European officials and threats of bans on exports of vaccines as the bloc tries to secure doses amid rising infections.

Also, more than a dozen European countries had halted use of the vaccine after blood-clotting reports. Most of the countries have resumed giving the shots, after an investigation didn’t find a link between the vaccine and the clotting events and reiterated that the vaccine’s benefits outweighed any potential risks.

Early this week, NIAID Director Anthony Fauci described AstraZeneca’s latest problem as an “unforced error.”

Pfizer Inc. Chief Executive Albert Bourla expressed concern at The Wall Street Journal Health Forum on Tuesday that the imbroglio could encourage hesitancy in taking Covid-19 vaccines generally.

AstraZeneca’s latest results, released late Wednesday night U.S. time, were largely consistent with preliminary findings reported Monday, based on trial data as of Feb. 17.

Aside from finding the vaccine 79% effective, the preliminary results indicated that the vaccine was even more effective in study subjects ages 65 years and older and that the shot was safe.

The late-stage, or Phase 3, trial had 32,449 subjects in the U.S., Peru and Chile. About 20% of them were 65 years or older.

The fuller data showed the vaccine to be 85% effective in the older age group. Older adults are considered more vulnerable to serious Covid-19, making them a high-priority group in vaccinations globally.