Possible New Links Identified With AstraZeneca COVID-19 Shot, Blood Clots

Scientists have identified a possible reason the AstraZeneca Plc's AZN COVID-19 vaccine may cause blood clots after the use of the shot was limited to prevent the rare side effect.

• The preclinical research conducted with AstraZeneca found that the interaction between the vaccine and a protein known as platelet factor 4 could be behind the cases of thrombosis with thrombocytopenia syndrome.
•  The study was published in the journal Science Advances by scientists from U.S. and U.K. universities and AstraZeneca. The research is not definitive, the company said.
• The vaccine, co-developed with the University of Oxford, has been hampered by a possible link between the shot and rare cases of blood clots.
• The U.K. limited its use to those over 40 years, and the U.S. has yet to authorize the vaccine. 
• Related Link: Europe's Drug Watchdog Concludes Possible Link Between AstraZeneca COVID-19 Vaccine And Blood Clots.
• "Although the research is not definitive, it offers interesting insights, and AstraZeneca is exploring ways to leverage these findings as part of our efforts to remove this extremely rare side effect," the company said in a statement.
• The company highlighted that the mechanism identified does not demonstrate it is the cause of the rare thrombosis, and most individuals who have PF4 antibodies will not develop clots. 
• Also See: No Increased Risk Of Blood Clots After Second Dose Of AstraZeneca's COVID-19 Shot, Study Shows.
• Price Action: AZN shares are down 0.13% at $53.81 during the market session on the last check Thursday.