Women who take the contraceptive pill should not worry about receiving the Oxford/AstraZeneca coronavirus vaccine over fears of rare blood clots, a leading thrombosis expert has said.
There is no evidence for any association with the jab and the pill, which has been linked to a very small risk of blood clots itself, Professor Beverley Hunt, professor of thrombosis and haemostasis at King’s College London, told i.
Figures suggest the chances of developing a blood clot after receiving the jab are very low, and experts have stressed it is incredibly safe and effective at protecting against Covid-19. However, concerns have been raised that women on the pill might be at a greater risk.
Prof Hunt, who is also medical director of charity Thrombosis UK, said: “They are two separate things… I know people are saying there might be an association with the thickened blood you see with the pill but there is no evidence whatsoever for that.”
Asked whether women on the pill should be worried if they are offered the vaccine, she said of the blood clot reports over the jab: “This is an immune response and it could happen to anybody, male or female, or people of any age.
“If you look at the European data, they’ve seen it more in women but that’s because they’ve been vaccinating healthcare workers and if you look at healthcare workers, they’re mainly women.”
People aged 18 to 29 in the UK should be offered the Pfizer or Moderna vaccines rather than the AstraZeneca jab, regulators have said.
Prof Hunt said the blood clots seen after the Oxford/AstraZeneca vaccine were unlike normal clots, such as deep vein thrombosis.
The vaccine is leading to “unusual” clots in a vein in the head, leaving patients with severe headaches or stroke-like symptoms because the blood supply to the brain has been affected.
“We’re seeing these problems always after day four. The first few days after a vaccine, you tend to have a few symptoms, [a] headache and feel unwell – we have not seen any cases then.”
The average time it takes to develop one of these clots is between 10 and 12 days. Experts have not seen any cases 28 days after the vaccine.
Prof Hunt made clear that blood clots from the vaccine are incredibly rare and that the UK’s thrombosis community is well-equipped to care for patients.
“We’re giving treatment that is very different from the treatment we would normally give people with blood clots. What I’m trying to say is the Medicines and Healthcare products Regulatory Agency have informed all the healthcare professionals, ‘Look out for this’. If people are looking out for it, then it’s more likely to be diagnosed early and we have treatment available now – we think it’s pretty good.
“[Readers] need to know that people are really aware of it, and [we’re] trying our best to find a way forward to get the very best care for these patients when they present.”