AstraZeneca Plc’s coronavirus vaccine performed better than expected in a US clinical trial, which provided reassurance about its safety and efficacy.
The plan developed with the Oxford University was 79% effective in preventing Covid-19, and an independent oversight committee found no safety concerns, the company said Monday. All immunized people were protected against serious illness and death in a study involving more than 30,000 volunteers.
The results should boost confidence in the vaccine after confusion over its effectiveness and the best dosing regimen slowed intake. The product is at the center of a supply standoff with the European Union just days after concerns over blood clots prompted a dozen member states to suspend vaccinations. Even after the The European Medicines Agency declared it safe last Thursday, not all EU countries have resumed vaccinations.
“Efficiency is better than we expected,” said Peter Welford, analyst at Jefferies in London. “Importantly, after recent largely unfounded security concerns in Europe, the study confirms the security profile.”
Read more: EU regulator considers Astra safe, but recommends warning label
Astra shares rose 1.4% in London trading. The company said it plans to submit the test data to US regulators in the coming weeks, in order to obtain clearance for an emergency use authorization.
Insufficient deliveries to the EU have put Astra disagrees with the bloc and has led officials to oppose the region’s shooting exports as they sought to hold the company to account.
Read more: Vaccine battle heats up with EU poised to halt UK shipments
The new data offers more clarity than the first results of the study published last November. These clinical trials, conducted in the UK and Brazil, produced a range of readings due to the different dosage amounts and regimens used. At least 10 EU countries only approved the vaccine for those under 65 to start with, as early trials lacked older participants. Many have since reversed course after more real-world usage data showed the vaccine to work for everyone.
Older adults made up about one-fifth of the US trial, which showed 80% effectiveness in this age group. The results “confirm that adults of all ages can benefit from protection against the virus,” Ann Falsey, professor at the The University of Rochester School of Medicine and one of the trial’s lead investigators, said in a statement.A number of cases involving rare but serious blood clots have also damaged the image of the vaccine. The EMA and the British regulator said Thursday that no definitive link could be made between the clots and the vaccine, and that the benefits of its use continued to outweigh the risks. The review of US trials that found no safety concerns looked specifically at blood clots.
Skepticism about the vaccine began last year when Astra and Oxford first communication of initial data. At the time, they offered two different efficiency readings of 62% and 90%. Due to a manufacturing error, a group of participants received a lower first dose, which produced the highest reading, compared to those receiving two standard doses. Further analysis suggested that it was the larger dosage variance rather than the amount that made the difference.
What Bloomberg Intelligence says
Why didn’t the efficacy look so good in its UK trial with a 4 week dosing interval, and is it likely to do even better with a 12 week gap? Unfortunately, this trial is too small to definitively address the few questions about side effects.
– Sam Fazeli, Senior BI Pharmaceutical Analyst
More than 70 countries around the world have approved the use of the Astra-Oxford shot and partners plan to produce until three billion doses of the vaccine this year.
The vaccine is key to the global effort to end the pandemic because it is easy to store and transport and the company is providing it profitably during the crisis. Unlike vaccines Pfizer Inc. and its partner BioNTech SE, and Moderna Inc., which must be stored frozen, the Astra shot can be stored at refrigerator temperature.
(Updates with planned submission to FDA in fifth paragraph)