Analysts praise AstraZeneca’s ‘surprisingly positive’ test data in the U.S.

Health analysts welcomed AstraZeneca’s findings about the final test results in the United States for its Covid-19 vaccine.

The trial of more than 30,000 participants in the USA, Peru and Chile found that the vaccine had an overall effectiveness of 79% in preventing symptomatic Covid and was 100% effective in preventing serious illness and hospitalization.

The effectiveness was consistent across all ages and ethnic groups, with 80% effectiveness in participants at least 65 years of age. The vaccine, known as AZD1222 and developed with the University of Oxford, was well tolerated and the independent data security monitoring council did not identify safety issues related to the vaccine, the company said on Monday.

In a research note, Jefferies health analyst Peter Welford called the data “surprisingly positive”.

Adam Barker, a health analyst at Shore Capital, said: “This is arguably the first trial of AZD1222 that has demonstrated convincing effectiveness in people aged 65 and over.”

This is important because there were doubts about the effectiveness in this age group. Previous studies were hampered by a smaller number of elderly participants. In this trial, 20% of participants were 65 years of age or older and 60% had comorbidities that put them at increased risk of developing serious illness.

Data from Monday’s trial confirmed the vaccine’s safety profile. Barker said that because the data is from a single trial using a single dosing regimen, they eliminate the complications of interpreting the data that were seen in the past with the AstraZeneca-Oxford vaccine.

Barker added that the lack of evidence of blood clots in the study was also comforting, given recent concerns. “However, we are not surprised by these data, as the evidence for a link between the vaccine and 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 use authorization in the coming weeks. The vaccine has already received conditional marketing authorization or emergency use in more than 70 countries on six continents.

“I can’t see why the regulator didn’t approve,” wrote Barker, but warned that the detailed data was still pending.

A key question for the FDA will be which dosing regimen it will endorse if it finally approves the vaccine for emergency use.

“This trial is based on the 4-week dosing interval, but we know that the effectiveness can be greater if you administer the dose over a longer interval (up to 12 weeks) and countries like the UK have successfully used this ‘duration’ strategy longer between doses’ to vaccinate more people quickly, “said Barker.

So the question for the FDA is whether they recommend giving the two doses four weeks apart – given what was tested in the American study – or include data from the UK and elsewhere that suggest that a longer duration is appropriate.

Welford also noted the suboptimal dosing regimen used in this study. “The trial evaluated the 4-week dosing schedule, but we have evidence to suggest that the vaccine works best with a longer dosing interval,” he said.

“The primary analysis of Phase III clinical trials in the UK, Brazil and South Africa showed 62% effectiveness when the vaccine was administered over a 4 to 12 week interval, but the effectiveness increased to 82% when the interval was extended for 12 weeks. “

In addition to the dosage, analysts are also on the lookout for additional details on how the vaccine protects against different variants. This is expected to be included in the data package sent to the FDA.

When it comes to comparing today’s efficacy data with that of some of the other vaccine manufacturers, Welford cautioned that since the initial readings of the Pfizer and Moderna vaccine, variants of Covid-19 have become increasingly common, so the efficacy data are not directly comparable across different vaccines.

Barker added that the trial results gave the vaccine important validation. “Given its cost and ease of storage and distribution, AZD1222 has already been described as a ‘vaccine for the world’. This is a fair label in our opinion, ”he wrote. “Data like this reported today that more conclusively demonstrate the effectiveness and safety of AZD1222 is certainly something to celebrate.”

AstraZeneca pledged to distribute the vaccine without profit during the pandemic. The company’s shares traded 2% higher in London on Monday.