The search for a safe covid-19 vaccine is not without risk.

AstraZeneca has shelved its covid-19 vaccine trial.

The company is investigating if a patient’s serious side effect resulted from the shot.

The company revealed no details about the side effect aside from calling it “a potentially unexplained illness.”

Last month, AstraZeneca started recruiting 30,000 US volunteers for its largest study.

A company spokesperson confirmed this includes the study in the US and other countries.

2 other companies have potential covid19 vaccines in final testing stages in the US.

This including 1 made by Moderna and the other by Pfizer and BioNTech.