United States Federal Health Agencies are recommending a pause in the administration of the single dose Johnson & Johnson COVID-19 vaccine in the country to allow them time to further investigate incidents of dangerous blood clots developing.

In a joint statement, the Food and Drug Administration and the Centres for Disease Control said it was investigating blood clots in six women after they all received the single dose shot.

In the cases, a type of blood clot called Cerebral Venous Sinus Thrombosis (CVST) was seen in combination with low levels of blood platelets (thrombocytopenia).

The vaccine is currently being rolled out to healthcare workers in South Africa as part of a research study while another 30 million market doses have been secured by government to be rolled out from May.

Health Minister Zweli Mkhize gives updates on the J&J clinical trials and rollout:

The FDA tweeted that they are recommending the pause out of an abundance of caution after these incidents of blood clots were experienced by six women within about two weeks of vaccination.

Reports in the country suggest that all the women were between the ages of 18 and 48 with one death and another in critical conditions.

More than 6.8 million doses of the J&J vaccine have been administered in the country to date while a further 9 million doses have been shipped to states.

The CDCs Advisory Committee on Immunisation Practices is expected to meet on Wednesday to discuss these developments while the FDA launches an investigation. Both agencies say it’s important for the healthcare provider community to be aware of the potential for these adverse events.

J&J said it was working closely with regulators and noted no clear causal relationship had been established between the events and the COVID-19 vaccine made by its Janssen unit.

Blood clots from another vaccine

The move comes a week after European regulators said they had found a possible link between AstraZeneca’s COVID-19 vaccine and a rare blood clotting problem that had led to a small number of deaths.

Lucy Huff on reports that Oxford-AstraZeneca vaccine causes blood clots:

Europe’s drugs regulator continues to recommend the use of AstraZeneca’s COVID-19 vaccine, saying the benefits outweigh the risks. Several EU countries, however, have limited its use to certain age groups.

Australia has no current plans to add J&J’s coronavirus vaccine to its immunisation drive, authorities said on Tuesday, as it moves away from procuring vaccines under review for potential links to blood clots.

– Additional reporting by Reuters