Johnson & Johnson vaccine to be halted in US over blood clot fears
US authorities have recommended pausing the roll-out of the single shot Johnson and Johnson vaccine after a small number of people experienced a severe form of blood clotting within two weeks of receiving their shot.
The J&J vaccine has been given to 6.8 million Americans so far, six of whom have developed cerebral venous sinus thrombosis – the same rare blood clot responsible for generating concern over the AstraZeneca jab’s safety. All six cases occurred in women aged between 18 and 48.
The Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) say they have recommended the pause “out of an abundance of caution” while they investigate the individual cases. “Right now, these adverse events appear to be extremely rare,” the FDA has said.
Johnson & Johnson has released a statement, saying it is aware that blood clots have been reported with some Covid-19 vaccines, but that “no clear causal relationship has been established between these rare events” and its shot.
The AZ and the J&J vaccines are similar in design; both use an adenovirus – the cause of some common colds – to deliver the coronavirus antigen and generate an immune response. The Sputnik vaccine also uses adenovirus technology, so if this aspect of the vaccine’s design is the cause of the rare side effects, the Russian vaccine might also pose a risk.
The J&J injection has been approved by the EU and the pharma company began shipments of the vaccine to member states on Monday. Meanwhile, the UK is expected to approve the J&J vaccine shortly and has already ordered 30 million doses.
This new blood clot scare is concerning at a time when the age restrictions imposed on the AZ vaccine have increased demand for alternative vaccines to inoculate the young.
Another unfortunate implication is that Johnson & Johnson and AstraZeneca are the two companies which have committed to selling their vaccines at-cost throughout the pandemic, meaning their vaccines are vital for many lower and middle-income countries.