A bottle of the AstraZeneca vaccine.
Igor Petyx | KONTROLAB | LightRocket via Getty Images
The data exceeded expectations
Jefferies health analyst Peter Welford described the data as “surprisingly positive” in a research report released Monday and wrote that the interim analysis was better than expected.
In the meantime, Adam Barker, Health Analyst at Shore Capital, said: “This is arguably the first study for AZD1222 that has shown convincing effectiveness in those 65 years and older.”
This is important as there have been some questions about effectiveness in this age group as previous studies have been hampered by a smaller number of older participants. In this study, 20% of participants were 65 years of age or older and 60% had comorbidities, which placed them at increased risk of developing serious illnesses.
The test data from Monday critically confirmed the safety profile of the vaccine. Barker emphasized that these data come from a single study using a single dosing regimen and remove the data interpretation complications seen in the past with the AstraZeneca-Oxford surge.
Barker added that the lack of evidence of blood clots in the study was also comforting given recent concerns. “We are not surprised by these data, however, as the evidence of a link between the vaccine and the blood clots was already quite weak.”
AstraZeneca said it will continue to analyze the data and prepare for the primary analysis to be submitted to the U.S. Food and Drug Administration for emergency approval in the coming weeks. The vaccine has already received conditional marketing or emergency marketing authorization in more than 70 countries on six continents.
Dosing regimen a key issue for the FDA
“I can’t understand why the regulator wouldn’t approve this,” Barker wrote, but warned that the detailed data is pending.
A key question for the FDA will be what dosage regimen they will support when they ultimately approve the vaccine.
“This study is based on dosing 4 weeks apart. However, we know that the effectiveness may be higher if you dose with a longer interval (up to 12 weeks) and countries like the UK have this” longer duration between “strategy The doses “used successfully to vaccinate more people quickly,” he relented.
So the question for the FDA is whether they recommend giving the two doses four weeks apart – assuming this was tested in the US study – or including data from the UK and other countries that suggest a longer one Duration is appropriate.
Welford also noted the sub-optimal dosing regimen used in this study. “The study evaluated the 4-week dosing schedule, but we have evidence that the vaccine works better with longer dosing intervals,” he said.
“The primary analysis of the UK, Brazil and South Africa Phase III clinical trials found 62% efficacy when the vaccine was given 4 to 12 weeks apart, but efficacy increased to 82% when the interval was 12 weeks has been extended. “”
In addition to the dosage, analysts are also paying attention to other details about protecting the vaccine from different variants. This is expected to be included in the data packet that will be submitted to the FDA.
Comparing today’s efficacy data with that of some other vaccine manufacturers, Welford warned that Covid-19 variants have become more common since the first vaccine advertisements from Pfizer and Moderna, so the efficacy data is not directly comparable to the efficacy data of various vaccines.
Barker added that the trial results gave the vaccine important validation. “Because of its cost and ease of storage and distribution, AZD1222 was once dubbed the ‘Vaccine for the World’. We think this is a fair label,” he wrote. “Data like this, reported today to be more conclusive about the effectiveness and safety of AZD1222, is certainly cause for celebration.”
AstraZeneca has committed to distribute the vaccine for the duration of the pandemic for no profit. The company’s shares traded 2% higher in London on Monday.