Amid recent news that six out of the 6.8 million people who have gotten the Janssen Vaccine have experienced rare blood clots in combination with low platelets, the U.S. called to pause for the Johnson & Johnson vaccines. The six who were sick have all been women who were between the ages of 18 and 48. One woman in Virginia died, and a second woman in Nebraska has been hospitalized in critical condition.

Dr. Anthony Fauci, President Biden’s chief medical adviser, emphasized the chances of these rare side effects were only 1 in a million. However, someone who got this dose recently should be alert to the symptoms such as severe headache, some difficulty in movement, abdominal pain, leg pain, some chest discomfort, and difficulty breathing. The symptoms were seen six to 13 days after vaccination.

According to an announcement by the FDA and CDC, they are investigating the cases in which women developed a blood clot called cerebral venous sinus thrombosis, which was associated with low blood platelet levels. They claimed, “Treatment of this specific type of blood clot is different from the treatment that might typically be administered. Usually, an anticoagulant drug called heparin is used to treat blood clots. In this setting, administration of heparin may be dangerous, and alternative treatments need to be given.”

The CDC’s Advisory Committee on Immunization Practices is set to meet Wednesday for an emergency session and Johnson & Johnson have made an official statement on their website about their suspension, where they also claimed they are going to delay the rollout of the vaccine in Europe.

However, The White House said Tuesday that the delay “will not have a significant impact” on the national vaccine program. President Biden told Americans that he had made sure the U.S. had enough vaccine doses for all American adults from Pfizer and Moderna alone.