WASHINGTON, United States (AFP)— The US Centers for Disease Control and Prevention (CDC) asked a group of medical experts to vote Thursday on whether they continued to recommend the Johnson & Johnson COVID-19 vaccine after more cases emerged of serious clotting.

At least nine people have died from clotting with low platelets or Thrombosis with Thrombocytopenia Syndrome (TSS) as of December 9, with around 16 million doses of the vaccine administered, according to new data released by the CDC.

There were 54 cases as of August 31, and 36 required admission to intensive care. Some of those who did not die had long term effects such as paralysis.

The greatest risks were seen in women aged 30-49, where the rate of TSS was around one in 100,000. Overall, approximately one out of seven cases have been fatal.

But the risk is not confined to this demographic, with two of the nine deaths among men. The CDC said nine may also be an underestimate.

CDC scientist Sara Oliver told a committee of independent experts there were several options available to them, including voting to recommend against using the vaccine altogether. 

But the CDC working group recommends a “preferential recommendation” which would mean the mRNA vaccines made by Pfizer and Moderna are recommended to most people, but the J&J vaccine, based on a viral vector platform, remains available for those who want it.

“The Johnson and Johnson COVID-19 vaccine is a life saving tool for individuals in high risk populations,” said Penny Heaton, global therapeutic area head of vaccines at J&J’s Janssen subsidiary said, arguing in favor of the shot.