The US is recommending a pause in the use of the Johnson & Johnson COVID-19 vaccine and the company is now delaying its rollout in Europe.
It's pending an investigation into reports of potentially dangerous blood clots.
Two US agencies are investigating clots in six women that were observed along with reduced platelet counts -- making the usual treatment with the blood thinner heparin, potentially dangerous.
The single-dose J&J shot has been approved for use in Canada, but no doses have arrived in the country yet.
More than 6.8-million doses have been administered in the US so far.