Pharmaceutical firm AstraZeneca has again updated its data on how well its coronavirus vaccine is working, announcing this week that it is showing 76% efficacy against symptomatic coronavirus disease and 100% efficacy against the severe or critical disease or the need for hospitalization.
The company also said the vaccine was 85% effective in preventing symptoms in those aged 65 and older.
The announcement follows a set of data released last Monday by the company that showed similar numbers. Just as with the initial data, AstraZeneca released the latest stats via a news release rather than a peer-reviewed report or as a formal submission for US Food and Drug Administration review.
“Positive high-level results from the primary analysis of the Phase III trial of AZD1222 in the US have confirmed vaccine efficacy consistent with the prespecified interim analysis announced on Monday 22 March 2021,” Mene Pangalos, executive vice president for biopharmaceuticals research for the company, said in a statement.
“These results have been presented to the independent Data Safety Monitoring Board. The primary analysis is pre-specified in the protocol and will be the basis for a regulatory submission for Emergency Use Authorization to the US Food and Drug Administration in the coming weeks.
“This primary efficacy analysis included the accrual of 190 symptomatic cases of COVID-19 from the 32,449 trial participants, an additional 49 cases to the previously announced interim analysis. Participants were randomized on a 2:1 ratio between the vaccine and placebo group.”
AstraZeneca’s Monday announcement was criticized by the independent Data and Safety Monitoring Board (DSMB) that reviews data from Covid-19 vaccine candidates and the National Institute of Allergy and Infectious Diseases made the unusual decision to publicly announce their concerns.
“The DSMB expressed concern that AstraZeneca may have included outdated information from that trial, which may have provided an incomplete view of the efficacy data,” the NIAID, which has helped AstraZeneca run trials in the US, said.
“We urge the company to work with the DSMB to review the efficacy data and ensure the most accurate, up-to-date efficacy data be made public as quickly as possible.”
AstraZeneca claimed on Monday that its Covid-19 vaccine exhibited 79% efficacy against symptomatic disease and 100% against severe disease and hospitalization.
32,500 volunteers across the Americas showed people receiving the vaccine were 76% less likely to have any coronavirus symptoms compared to the one-third of participants that were given the placebo.
“There were 190 cases in the primary analysis. There are 14 additional possible or probable cases to be adjudicated so the total number of cases and the point estimate may fluctuate slightly,” the company said.
“AstraZeneca will also submit the primary analysis for peer-reviewed publication in the coming weeks.”
As has been the case in all coronavirus vaccine trials, the volunteers were not regularly tested for Covid-19, so it’s not known how many may have gotten asymptomatic infections.
“A key secondary endpoint, preventing severe or critical disease and hospitalization, demonstrated 100% efficacy. There were eight cases of severe COVID-19 observed in the primary analysis with all of those cases in the placebo group,” the company said.
“The vaccine was well tolerated, and no safety concerns related to the vaccine were identified.
National Institute of Allergy and Infectious Diseases director Dr. Anthony Fauci brandished AstraZeneca’s release of premature data an “unforced error”.
Speaking to ABC’s Good Morning America on Tuesday, Fauci said that the AstraZeneca vaccine “is very likely a very good vaccine,” and that the situation does nothing but only serve to create doubt about the vaccines and thus contribute to vaccine hesitancy.
“We are always concerned when there is an apparent miscommunication… If you want to use that word, that that would add to an already existing level of vaccine hesitancy. And that’s the reason why, as Andy said, we want to make sure we’re always completely transparent in everything that goes on with regard to a messaging in vaccine,” Dr. Fauci said at the White House COVID-19 Response Team & Task Force press briefing.
“At the end of the day, when you look at the data, this is going to be turned out to be a good vaccine. As Andy said, the final determination of the analysis of the data will be done by the FDA. When that is done, that is going to be very transparent as they meet with their VRBPAC, their advisory committee. So at the end of the day, everything is going to be open and transparent. And hopefully that will dispel any hesitancy that was associated with this little bump in the road that we happen to have most recently with AZ.”
“I’m enthusiastic about the pace that vaccination that is happening about the early data that we’re seeing, of the changes in infection rates, the changes in emergency department rates,” Dr. Walensky said at the same press briefing.
“What worries me is that while we have about 24% of the population that has received one dose and about 13% of the population that is fully vaccinated, what concerns me is the footage of what’s happening in Spring Breakers, in people who are not continuing to implement prevention strategies while we get fully scaled up. We’re at 13%. We need to be much higher than that to feel like we have adequate protection around this country.”