JUSTIN TALLIS/AFP / Getty Images

The U.S. government has halted distribution of all Johnson & Johnson single jab mRNA vaccines after concerns about blood clots in the brain.

Federal authorities have halted distribution of Johnson & Johnson injections at all government facilities, and are asking states to do the same.

According to a report in the NY Times, six women between the ages of 18 and 48 complained of blood clots. Only one woman died.

The Federal Food & Drug Administration (FDA) tweeted: "We are recommending a pause in the use of this vaccine out of an abundance of caution."

Photo may have been deleted

The six women were diagnosed with a rare blood clotting disorder called cerebral venous sinus thrombosis (CVST).

The women also had low blood platelets count (thrombocytopenia) which causes hemorrhaging (bleeding) in the brain and body. Among the first signs are frequent nosebleeds, bleeding gums, black, tarry stools, and blood in urine.

AFP via Getty Images

The Johnson & Johnson single jab vaccine was praised by the news media because it required only a single injection.

Other experimental mRNA vaccines, including Pfizer and Moderna, require two shots spaced about 21 days apart.

Critics of Johnson & Johnson and other experimental vaccines were quickly branded anti-vaxxers.
 

FYI: An earlier version of this article reported that six women died from blood clots. Only one woman has died.