Pharmaceutical company AstraZeneca issued a statement Sunday reiterating the safety of its COVID-19 vaccine based on scientific evidence amid concerns over reports of people developing blood clots after receiving it.

The company said safety was of paramount importance for them and that they continually monitor the safety of the vaccine.

"A careful review of all available safety data of more than 17 million people vaccinated in the EU and UK with COVID-19 Vaccine AstraZeneca has shown no evidence of an increased risk of pulmonary embolism, deep vein thrombosis (DVT) or thrombocytopenia, in any defined age group, gender, batch or in any particular country," it said.

It noted that so far across the EU and UK, there have been 15 events of DVT and 22 events of pulmonary embolism reported among those given the vaccine, based on the number of cases the company has received as of March 8.

"This is much lower than would be expected to occur naturally in a general population of this size and is similar across other licensed COVID-19 vaccines. The monthly safety report will be made public on the European Medicines Agency website in the following week, in line with exceptional transparency measures for COVID-19," the statement said.

The company stressed that in clinical trials, even though the number of thrombotic events were small, these were lower in the vaccinated group and that there has also been no evidence of increased bleeding in over 60,000 participants enrolled.

“Around 17 million people in the EU and UK have now received our vaccine, and the number of cases of blood clots reported in this group is lower than the hundreds of cases that would be expected among the general population. The nature of the pandemic has led to increased attention in individual cases and we are going beyond the standard practices for safety monitoring of licensed medicines in reporting vaccine events, to ensure public safety,” said Ann Taylor, the company’s chief medical officer.

"In terms of quality, there are also no confirmed issues related to any batch of our vaccine used across Europe, or the rest of the world. Additional testing has, and is, being conducted by ourselves and independently by European health authorities, and none of these re-tests have shown cause for concern," the statement said.

It was noted that during the production of the vaccine, more than 60 quality tests were conducted by AstraZeneca, its partners and by more than 20 independent testing laboratories.

"All tests need to meet stringent criteria for quality control, and this data is submitted to regulators within each country or region for independent review before any batch can be released to countries," the statement said.

It said the company would keep the issue under close review but noted that available evidence did not confirm that the vaccine is the cause.

"To overcome the pandemic, it is important that people get vaccinated when invited to do so," it said.