AZ, J&J to research modifications to COVID-19 vaccines over rare blood clot issues

AstraZeneca (AZ) and Johnson & Johnson (J&J) are planning to explore possible modifications to their respective COVID-19 vaccines in response to rare blood clots linked to the jabs. 

J&J, AZ and the University of Oxford, alongside outside scientists, are planning to conduct early research into the potential of modifications to their vaccines to reduce or remove the risk of rare but serious blood clots associated with the jabs, The Wall Street Journal (WSJ) has reported.

While a J&J spokesman said the company supports “continued research and analysis”, AZ said it is ““actively working with the regulators and scientific community to understand these extremely rare blood-clotting events, including information to drive early diagnosis and intervention, and appropriate treatment”, as quoted by WSJ.

The rare blood clotting issue – referred to by some scientists as vaccine-induced immune thrombotic thrombocytopenia (VITT) – has been associated with both the AZ and J&J COVID-19 vaccines.

Earlier this year, the US Food and Drug Administration (FDA) said it would add a warning label to J&J’s vaccine relating to the blood clotting issue, labelling it as a rare side effect.

According to data from both the UK and Europe, the rate of the rare blood clotting issue is around one to two cases per 100,000 doses for the AZ vaccine.

Data from the US Centers for Disease Control and Prevention (CDC) estimates the rate to be around 0.3 cases per 100,000 doses of the J&J vaccine.

This week, The Washington Post reported that the FDA has added the rare neurological condition Guillain-Barré syndrome as a potential side effect of the J&J COVID-19 vaccine.

The FDA has reportedly warned there is data ‘connecting the [vaccine] to an increased risk’ of Guillain-Barré syndrome, which occurs when the immune system begins to attack nerves in the body.

There have been 100 reports of the syndrome in people who have received the J&J vaccine, out of nearly 13 million individuals in the US who have received the jab, according to The New York Times.

Of those reported cases, 95 resulted in hospitalisation and one was fatal, with the syndrome primarily reported in men. Many of the reported cases occurred in people aged 50 years and over, officials added.

Although there is not yet enough evidence to clearly link the vaccine to the condition, the FDA said it is continuing to monitor the situation.