The risks of developing neurological complications following Covid-19 infection ‘are much greater’ than those associated with Covid-19 vaccinations, according to a UK-based study led by the University of Oxford.
In one of the most extensive population-based studies to examine the risk of developing adverse neurological reactions in response to Covid vaccinations, the researchers found neurological complications are more likely to occur as a result of being infected by Covid-19.
People who received the Oxford-AstraZeneca vaccine had a very small increased risk of developing two types of neurological conditions, Bell’s palsy and Guillain-Barre syndrome, while those receiving the Pfizer-BioNTech vaccination had an increased risk of haemorrhagic stroke. The risk of these complications is greater following a positive Covid-19 test.
The results of the study are published in Nature Medicine.
The researchers from across the UK, and independent from Oxford vaccine developers, examined the health records of over 32 million people in England, including data from the English National Immunisation (NIMS) Database, who had been vaccinated against Covid-19 with either the Oxford- AstraZeneca or the Pfizer-BioNTech vaccination. They assessed the risk of developing neurological complications within 28 days of a first dose of either vaccine or within 28 days of a positive Covid-19 PCR test.
The researchers found 145 excess cases of Guillain-Barre syndrome per 10 million people in the 28 days after a positive Covid-19 test, compared to 38 per 10 million for those who received the Oxford-AstraZeneca vaccine.
Julia Hippisley-Cox, professor of clinical epidemiology and general practice at the University of Oxford, and co-author said: ‘Whilst there are some increased risks of very rare neurological complications associated with the Oxford-AstraZeneca vaccine, these are much smaller than the risks associated with Covid infection itself.’
Oxford-AstraZeneca vaccine trials were temporarily paused due to two cases of neurological complications, which led to some countries limiting the use of the vaccine in younger people with reduced risk of severe outcomes from Covid-19 infection.
Dr Lahiru Handunnetthi, from the University of Oxford, and co-lead author of the paper, added: ‘These neurological complications were very rare, but awareness of these will be important for patient care during mass vaccination programmes across the world.’
Confirmatory analysis was undertaken using Scotland’s national Covid-19 dataset (EAVE II), leading the researchers to conclude in their paper that the study highlighted ‘the benefits of an ongoing vaccination programme’.