(Bloomberg) -- AstraZeneca Plc’s Covid-19 vaccine looks like it’s headed for an additional global trial as the drugmaker tries to clear up uncertainty and confusion surrounding favorable results in its current study.

The company wants the new test to confirm the 90% efficacy rate that the shot showed in a portion of an existing trial, Chief Executive Officer Pascal Soriot said. It’s favoring that option rather than adding an arm to a separate study that’s already underway in the U.S.

Questions are mounting over one of the fastest-moving shots after the company acknowledged that a lower dosage level that appeared more effective resulted from a manufacturing discrepancy. The company and its partner, the University of Oxford, didn’t initially disclose the error and other key details, leading to concern over their transparency.

More in category

The Best Hiking Socks for Hitting the Trails This Spring
February 24, 2021MSN
The Best Hiking Socks for Hitting the Trails This Spring
Helping People Find Covid-19 Vaccines Is Aim of C.D.C.-Backed Site
February 24, 2021The NY Times
Helping People Find Covid-19 Vaccines Is Aim of C.D.C.-Backed Site
Late-Window Stroke Thrombolysis Not Linked to Clot Migration
February 24, 2021Medscape
Late-Window Stroke Thrombolysis Not Linked to Clot Migration
This Trial Allows for Medical Abortion Via the Mail
February 24, 2021MSN
This Trial Allows for Medical Abortion Via the Mail
This Compact Lamp for Light Therapy Is Loved by Over 2,600 Amazon Shoppers—and 'Health' Readers Get a Discount
February 24, 2021MSN
This Compact Lamp for Light Therapy Is Loved by Over 2,600 Amazon Shoppers—and 'Health' Readers Get a Discount
A guide to your first birth control appointment and questions to ask your doctor
February 24, 2021MSN
A guide to your first birth control appointment and questions to ask your doctor
This spin bike is nearly half the price of Peloton and more like a full home gym
February 24, 2021MSN
This spin bike is nearly half the price of Peloton and more like a full home gym
6 Ways to Support the Asian Community Right Now
February 24, 2021MSN
6 Ways to Support the Asian Community Right Now
The Six-Mile Central Park Loop Has Been Renamed After Running Pioneer Ted Corbitt
February 24, 2021MSN
The Six-Mile Central Park Loop Has Been Renamed After Running Pioneer Ted Corbitt
Israel study says Pfizer vaccine is very effective in real-world use
February 24, 2021MSN
Israel study says Pfizer vaccine is very effective in real-world use
Don’t Be So Hard On Yourself: Why Negative Self-Talk Is a Parent’s Worst Enemy
February 24, 2021MSN
Don’t Be So Hard On Yourself: Why Negative Self-Talk Is a Parent’s Worst Enemy
A New Coronavirus Variant Is Spreading in New York, Researchers Report
February 24, 2021The NY Times
A New Coronavirus Variant Is Spreading in New York, Researchers Report
Fauci Introduces New Acronym for Long COVID
February 24, 2021Medscape
Fauci Introduces New Acronym for Long COVID
Moderna Variant-Specific Vaccine Ready to Study
February 24, 2021Medscape
Moderna Variant-Specific Vaccine Ready to Study
Big Data 'Clinches' Link Between High Glycemic Index Diets and CVD
February 24, 2021Medscape
Big Data 'Clinches' Link Between High Glycemic Index Diets and CVD
How 'I Care a Lot' Used Locations to Convey Power
February 22, 2021Men's Health
How 'I Care a Lot' Used Locations to Convey Power
This Press Variation Is Great for Older Guys
February 23, 2021Men's Health
This Press Variation Is Great for Older Guys
Annie's promises to remove a chemical from its mac and cheese that's linked to infertility, cancer, and learning difficulties
February 24, 2021MSN
Annie's promises to remove a chemical from its mac and cheese that's linked to infertility, cancer, and learning difficulties
The Pfizer vaccine’s initial success holds up in wider use, a study finds.
February 24, 2021The NY Times
The Pfizer vaccine’s initial success holds up in wider use, a study finds.
Big Data 'Clinches' Link Between High Glycemic Index Diets and CVD
February 24, 2021Medscape
Big Data 'Clinches' Link Between High Glycemic Index Diets and CVD
How 'I Care a Lot' Used Locations to Convey Power
February 22, 2021Men's Health
How 'I Care a Lot' Used Locations to Convey Power