J&J poses ‘rare’ blood clot risks

Known benefits of Janssen Covid-19 shot greatly outweigh the potential risks, says Sahpra CEO

THE SA Health Products Regulatory Authority (Sahpra) has noted four cases of thrombosis with thrombocytopenia syndrome (TTS), following the administration of the Johnson & Johnson Janssen Covid-19 vaccine.

Last week, Sahpra said the four cases of TTs in South Africa follow 8 589 109 vaccinations with the Covid-19 Janssen vaccine.

Sahpra spokesperson Yuven Gounden said TTS is a very rare, new and specific syndrome reported with Covid-19 vaccines.

“This translates to 1 case in about 5 000 000 doses in South Africa. Furthermore, more than 26 million Pfizer doses have been administered so far, with no cases of TTS confirmed. This indicates that TTS is a very rare phenomenon.”

TTS occurs when a person has blood clots (thrombosis) as well as low platelet counts (thrombocytopenia). TTS risk factors include: trauma, immobility, inherited disorders (genetic), autoimmune disease, obesity, hormone replacement therapy or birth control pills, pregnancy, cancer, and older age.

Sahpra CEO Dr Boitumelo Semete-Makokotlela said two cases reported from the Sisonke cohort were confirmed to be TTS and have fully recovered, and the remaining two cases are still under investigation.

On April 13, 2021, the US Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) recommended a pause in administration of the Janssen vaccine, to investigate six cases of TTS.

On May 5, the FDA limited the use of the Janssen vaccine after conducting an updated investigation, stating that the risk of TTS warrants the limitation.

Semete-Makokotlela said Sahpra, in line with the World Health Organization and European Medicines Agency, has determined that the known benefits of the Janssen vaccine greatly outweigh the known and potential risks.

“Sahpra continues to monitor closely the efficacy against variants of concern and the safety profile of the Covid19 vaccine Janssen as determined in the approved risk management plan. The Covid-19 vaccine Janssen remains effective in reducing disease severity and hospitalisation.”

Sisonke study co-lead investigator Professor Linda-Gail Bekker said a similar syndrome is seen with Heparin, a prescription medicine used to treat and prevent the symptoms of blood clots caused by medical conditions or medical procedures.

Bekker said there was a very low incidence of cases per million of vaccines delivered, translating still into a good benefit to risk ratio.

All adverse events following immunisation can be reported via the Med Safety App.