The U.K. drugmaker is poised to unveil vaccine test results by year-end even after trials were slightly delayed over the summer as infection rates slowed in the northern hemisphere. A recent resurgence has allowed scientists to gather the clinical data they need, according to Soriot. Astra and the University of Oxford are keeping the vaccine in a frozen bulk state to preserve its shelf life while they await final test results.

“At the end of the day, we don’t yet know if the vaccine works,” Soriot said in a Bloomberg Television interview, adding that many questions remain, such as whether it will show results for everyone and for how long. “We would hope that large-scale vaccinations would be possible starting in January next year—possibly even December.”

Soriot’s remarks come a day after Kate Bingham, chair of the U.K. Vaccine Taskforce, said only 4 million doses of the shot would be available by the end of the year, far fewer than the 30 million that were due to be ready by September. AstraZeneca said it’s confident it can begin supplying hundreds of millions of doses on a “rolling basis” once a shot is cleared.

The U.K. drugmaker has been at the forefront of efforts to fight the pandemic, and its experimental shot could be one of the first to be approved globally if successful. Astra and drugmakers Pfizer Inc. and Moderna Inc. are all seeking to deliver crucial test results on a vaccine in the coming weeks, with emergency clearance possible before the end of the year.

Soriot said the world needs several vaccines and that Astra studies conducted in the U.K. and Brazil kept progressing well even as the U.S. one suffered a halt. It’s possible the U.S. Food and Drug Administration will want to wait for the results of the local trial before reviewing the product, he said.

The FDA “may want to wait for the results of the U.S. study or they may review our international program and give us an emergency approval on that basis,” Soriot said. “It will be up to regulators in individual countries to decide.”

Vaccine Timeline

Astra has said it will sell the vaccine at cost during the pandemic at a price tag of between $4 to $5, depending on local manufacturing charges. The company said recently it would add as much as 20% to cover manufacturing costs to avoid any material impact on its finances. Astra is incurring a bill in excess of $1 billion globally for expenses including clinical development, Soriot said.

The Astra-Oxford candidate has produced a robust immune response in older adults and the elderly, those at highest risk of severe illness. Astra and Oxford have enrolled about 23,000 volunteers in vaccine trials globally, with plans to reach 50,000 once the U.S. arm has completed recruitment.

A U.K. government spokesperson said Thursday that “a vaccine will only be deployed once proven to be safe and effective” and that the National Health Service was ready to start the vaccination program.

Pandemic Disruption

Pfizer, which is developing its vaccine with Germany’s BioNTech SE, has said it may release initial late-stage trial data this month. The company is also waiting to hit a safety milestone, two months of data on half of participants, which it expects by the third week of November. Assuming both sets of results are positive, it would apply for emergency use authorization in the U.S. shortly thereafter.

Astra on Thursday reported third-quarter profit that fell short of analysts’ estimates as the pandemic inflated costs and discouraged some doctors’ visits and diagnoses. Other drugmakers such as Switzerland’s Novartis AG and Denmark’s Novo Nordisk A/S also cited similar disruptions.

“Believe it or not, people are having heart attacks and they don’t go to the hospital because they are scared,” Soriot said on a conference call, also citing delays in cancer diagnoses and treatment. Injectable products are more affected by such slowdowns, he said.

Astra shares were little changed in London trading.