There is an elevated risk of cardiac-related death in young women who have received non-mRNA vaccines, a study has found.
The risk of dying from heart issues was three and a half times higher among young women in the 12 weeks following a single dose of the non-mRNA type of Covid vaccine, the study conducted by the Office for National Statistics in England found.
The study analysed hospitalisation, vaccination records and death registrations among 12 to 29-year-olds to assess the impact of Covid-19 vaccinations and infection.
However, overall among 12 to 29 year-olds in England mortality was not significantly increased in the first 12 weeks after a vaccination, compared to the longer-term risk.
Those who received the AstraZeneca Covid vaccine, which is a non-mRNA, were more likely to be clinically vulnerable and may be at greater risk of adverse events than the general population.
Eleven out of the 15 cardiac-related deaths in young women that occurred within the first 12 weeks of first dose of a non-mRNA vaccine were likely to be linked to the vaccine, corresponding to 6 cardiac-related deaths per 100,000 females vaccinated with at least a first dose of a non-mRNA vaccine, it showed.
The ONS said that a positive SARS-CoV-2 test was associated with increased cardiac and all-cause mortality, with the risk being higher in those who were unvaccinated at the time of testing than in those who were vaccinated.
A senior statistician at ONS, Vahe Nafilyan, said: “While vaccination carries some risks, these need to be assessed in light of its benefits. Our analysis shows that the risk of death is greatly increased following a positive test for Covid-19 even in young people and many studies show that vaccines are highly effective at preventing hospitalisation or death following infection.”
However, more details are needed about the nature of the reported cardiac events as concerns about rare cardiac side effects, specifically myocarditis and pericarditis, have previously been particularly associated with mRNA vaccine second doses in males, especially when the dose interval was short. But the ONS study primarily focuses on non-mRNA first doses in females.
The ONS also noted that most of the young people who received the AstraZeneca vaccine before April 2021 would have been prioritised due to underlying health conditions or because they were healthcare workers, so the 3.5 times greater risk cannot be generalised to the whole population.
