(Karachi) Amid speculations about patients developing post-jab blood clots by AstraZeneca's COVID-19 vaccine, the US National Institute of Allergy and Infectious Diseases (NIAID) has showed concern that the British drugmaker may have provided an incomplete data of its vaccine's efficacy, local media reported.

"The Data Safety Monitoring Board (DSMB) has expressed concern that AstraZeneca may have included outdated information from that trial, which may have provided an incomplete view of the efficacy data," the US agency said.

The NIAID stated, "We urge the company to work with the DSMB to review the efficacy data and ensure the most accurate, up-to-date efficacy data be made public as quickly as possible."

Meanwhile, AstraZeneca which developed the vaccine in cooperation with Oxford University, has defended the safety of its product. The firm stated that the safety of the vaccine has been extensively studied in phase III clinical trials and peer-reviewed data confirms the vaccine has been generally well tolerated.

Earlier, several European and Scandinavian states including Denmark, Norway and Iceland temporarily suspended the use of AstraZeneca's Covid-19 vaccine after fears of developing post-jab blood clots. Later, they resumed AstraZeneca vaccinations after the European Medicines Agency said hat the jab is "safe and effective" and is not linked to an increased risk of blood clots.

In September 2020, AstraZeneca had suspended global trials of its experimental coronavirus vaccine after an unexplained illness in a participant in Britain.

The vaccine had been described by the World Health Organization as probably the world's leading candidate and the furthest developed.