Teams at Johnson & Johnson, AstraZeneca and the University of Oxford are working with outside scientists to potentially modify their COVID-19 vaccines to reduce or eliminate the risk of rare but dangerous blood clots that have been linked to the shots, The Wall Street Journal (WSJ) reported on Tuesday, citing people close to the process.
The research is in its early stages, but “fast-developing clues into how the clots form — driven in part by independent scientists in Europe, the US and Canada — are boosting hopes of identifying the cause and possibly re-engineering AstraZeneca’s shot by next year”, the WSJ reported, citing some of the people close to the process.
It is not yet certain whether the two vaccines can be modified or whether it makes commercial sense to do so, the paper said.
A J&J spokesman told the WSJ that the company supports “continued research and analysis as we work with medical experts and global health authorities”.
AstraZeneca has 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”, the WSJ reported.
In April, the US Food and Drug Administration and the US Centers for Disease Control and Prevention (CDC) called for a pause in the use of J&J’s COVID-19 vaccine after it was linked to rare cases of severe blood clots, but they lifted the temporary halt after determining that the vaccine’s benefits outweighed its risks.
The AstraZeneca vaccine has not been approved for use in the US but is widely used in other parts of the world. Regulators in the United Kingdom and Europe, where it has been extensively used, have recommended that younger people, who are thought to be more susceptible to the clots, receive a different COVID-19 vaccine, the WSJ reported.
Separately, both the J&J and AstraZeneca vaccines are being scrutinised for links to Guillain-Barre syndrome – a disorder in which the immune system attacks the nerves. On Monday, US regulators added a warning to the J&J vaccine of a small but increase risk of the disorder.
The CDC said in a statement on Monday that about 100 preliminary reports of Guillain-Barre syndrome have been detected after 12.8 million doses of J&J’s COVID-19 jab in the US.
Regulators in Europe have also recommended a similar warning that AstraZeneca’s COVID-19 vaccine could lead to an increased risk of Guillain-Barre syndrome.