Johnson & Johnson, AstraZeneca researching vaccine modification to address rare blood clot risk

Johnson & Johnson, AstraZeneca researching vaccine modification to address rare blood clot risk
© Getty Images

Johnson & Johnson (J&J) and AstraZeneca are researching vaccine modification to address the rare blood clot risk associated with the companies’ coronavirus vaccines. 

People familiar with the situation told The Wall Street Journal the two companies and people at the University of Oxford are in the early stages of research to identify why the vaccines are causing rare blood clots and what can be done to stop it.

The sources say it is not clear yet if the vaccine can be modified or if it would make commercial sense to do so.


Officials say the benefits outweigh the risk with the AstraZeneca and J&J vaccines since the risk of blood clots is so small. 

It is unknown if the risk of blood clots is coming from the process used to make the vaccines or the ingredients inside them.

Figuring out how to solve the risk of blood clots could boost public confidence and allow the companies to make money off the vaccines once the pandemic is over. 

Public confidence is key as many countries, including the U.S., are struggling to get their population vaccinated. 

“We strongly support awareness of the signs and symptoms of this very rare event to ensure the correct diagnosis, appropriate treatment and expedited reporting by health care professionals. We also support continued research and analysis as we work with medical experts and global health authorities,” J&J said in a statement to The Hill.

Sources told the Journal there is hope the cause of the blood clots can be identified and AstraZeneca could modify their vaccine by next year if that happens. 


“AstraZeneca is actively working with the regulators and scientific community to understand these extremely rare blood-clotting events, including information to drive early diagnosis and intervention, and appropriate treatment,” a company spokesperson told The Hill in a statement. 

However, changing the vaccine could lead to needing reapproval from regulatory agencies and changing ownership rights, the Journal noted.

The J&J vaccine was temporarily paused in the U.S. after the blood clot risk was discovered. The AstraZeneca vaccine was also paused in countries where it was being used due to the risk. 

Both vaccines have been taken off of pause and used to vaccinate millions of individuals.