AstraZeneca PLC may have included "outdated" information from its coronavirus vaccine trial when reporting the results, possibly providing an "incomplete view of the efficacy data," the U.S. National Institute of Allergy and Infectious Diseases said Tuesday.

The questions were raised after the British biopharmaceutical company announced Monday that its vaccine was 79 percent effective in preventing the disease caused by the novel coronavirus in a clinical trial conducted in the United States and two South American countries.

Photo shows bottles of COVID-19 vaccine developed by AstraZeneca Plc and the University of Oxford. (Photo courtesy of AstraZeneca)(Kyodo)

 

The company has also said experts have identified no safety concerns related to the vaccine, including any increased risk of blood clots. Blood clots among those who received the shots have been reported in Europe, leading France and other countries to temporarily suspend use of the AstraZeneca vaccine.

Late Monday, an independent safety monitoring board notified the institute that "it was concerned by information" released by AstraZeneca on initial data from its vaccine clinical trial, according to the institute's press release.

"We urge the company to work with the Data and Safety Monitoring Board to review the efficacy data and ensure the most accurate, up-to-date efficacy data be made public as quickly as possible," it said.

The numbers published Monday were based on an interim analysis with a "data cut-off" of Feb. 17, AstraZeneca said in a press release, adding that it has conducted a review and the results "were consistent with the interim analysis."

The company also said it plans to swiftly issue the results of its primary analysis with the most up-to-date efficacy data.

The AstraZeneca vaccine has already been approved for use in more than 70 countries around the world. The company is planning to seek emergency use authorization from the U.S. drug regulator.

Japan is currently examining the drugmaker's application for use of its vaccine in the country.