On Tuesday, the Food and Drug Administration is asking states to temporarily halt the use of the Johnson & Johnson vaccine after six women in the U.S. developed a rare blood-clotting disorder after receiving the Johnson & Johnson COVID vaccine. One woman died, and another was left in critical condition.

"Right now, these adverse events appear to be extremely rare," the FDA said in a joint statement with the Centers for Disease Control and Prevention. "COVID-19 vaccine safety is a top priority for the federal government, and we take all reports of health problems following COVID-19 vaccination very seriously."

The clots originated in veins that drain blood from the brain and additionally caused low platelets. All six cases occurred in women between the ages of 18 and 48. More than 6.8 million doses of the J&J vaccine have been administered in the U.S., an extensive majority without little to no side effects. President Biden's COVID czar, Jeffrey Zients, told NBC News that the pause will not have a "significant impact" on the administration's goal to administer 200 million COVID shots within Biden's first 100 days in office. Currently, J&J vaccines make up less than 5% of the recorded shots in the U.S. "Based on actions taken by the President earlier this year, the United States has secured enough Pfizer and Moderna doses for 300 million Americans," Zients said in a statement. "Over the last few weeks, we have made available more than 25 million doses of Pfizer and Moderna each week, and in fact this week we will make available 28 million doses of these vaccines." As the FDA and other authorities investigate whether the clots really are related to the J&J vaccine, health experts are emphasizing the importance of Americans getting vaccinated as soon as possible through the Pfizer and Moderna vaccines. "If you have a chance to get vaccinated with those, we strongly encourage it. The risks of COVID are real and they're high," Geoffrey Barnes, a clot expert at the University of Michigan, told the Associated Press. Each of the women affected by the blood-clotting issue developed symptoms developing six to 13 days after they received the shot. In a statement, J&J said that "no clear causal relationship" has been identified between the blood clots and the vaccine, adding it is working closely with the CDC and FDA and other regulators to assess the data. If you received the J&J vaccine and develop a severe headache, abdominal pain, leg pain or shortness of breath within three weeks after the vaccination, the FDA and CDC recommend contacting your healthcare provider right away, or calling 911 or heading to the emergency room.