Following a safety review, the FDA and the CDC have lifted the recommended pause on the Johnson & Johnson COVID-19 vaccine.

The recommended pause came after reports of six cases of a rare and severe type of blood clot in individuals following administration of the Janssen COVID-19 vaccine. During the pause, medical and scientific teams at the FDA and CDC examined available data to assess the risk of thrombosis involving the cerebral venous sinuses, or CVST (large blood vessels in the brain), and other sites in the body. They also evaluated the risk of low blood platelet counts, also known as thrombosis-thrombocytopenia syndrome (TTS).

According to a press release from the two agencies, the available data suggest that the chance of TTS occurring is very low, but the FDA and CDC will remain vigilant in continuing to investigate this risk.

“Safety is our top priority. This pause was an example of our extensive safety monitoring working as they were designed to work—identifying even these small number of cases,” Janet Woodcock, MD, acting FDA commissioner, said in a statement.

The teams at FDA and CDC also conducted outreach to providers and clinicians to ensure they were made aware of the potential for these adverse events and could properly manage and recognize these events due to the unique treatment required for these blood clots and low platelets.