Patients who previously had Covid are far more likely to suffer side effects from the Pfizer jab, a UK study has revealed.
A third (33%) of people in this group reported ‘mild whole-body’ side effects such as fatigue, headache and shivers after their first dose, compared with a fifth (19%) of patients who had not had Covid.
Although further research is needed, scientists behind the study suggested this may indicate that Covid survivors may only need one dose of the vaccine, rather than the current two-dose schedule.
The study data – based on 40,000 vaccinations – comes from the Zoe Covid Symptom Study app, which asked people to log any side effects on the system for seven days following their vaccination.
It also showed that 37% of people experienced some ‘local after effects’ such as pain or swelling near the site of the injection after the first dose, rising to 45% for those who had the second.
Also, 14% of people reported at least one ‘whole-body after effect’ within seven days of the first dose, increasing to 22% after the second, according to the figures.
Lead researcher Professor Tim Spector, professor of genetic epidemiology at King’s College London, said: ‘This suggests that those getting a first dose after having had Covid are generating a stronger immune reaction and may get greater protection from just a single shot of the vaccine.’
Speaking about the findings during an online webinar, Mr Spector said that for people who have previously been infected – the first vaccine is ‘behaving a bit like a booster’ jab, adding that ‘with a bit more data, we might be able to say these people don’t need a second booster’.
This would potentially save 10 million vaccines, or allow some vaccinations to be delayed for several months, he added.
The news comes as the MHRA’s first yellow card scheme report from the Covid vaccination programme last week revealed that the vast majority of side effects reported were ‘mild and short lasting’.