Over seven years, cardiovascular disease was recorded less often in recipients of the recombinant shingles vaccine than in recipients of the live vaccine
Over seven years, cardiovascular disease was recorded less often in recipients of the recombinant shingles vaccine than in recipients of the live vaccine
A Nature Medicine study published on 26 August compared two historical cohorts of US patients older than 60 years, one before and one after the switch from a live attenuated virus vaccine to a recombinant vaccine containing a viral protein. The recombinant vaccine cohort remained free of recorded cardiovascular diagnoses for longer.
After October 2017, the recombinant vaccine quickly replaced the live attenuated virus vaccine. This change in the vaccination standard created a natural experiment. The researchers compared people who had already chosen to be vaccinated before and after the transition.
The authors included people who received their first dose between April and September 2017 and those vaccinated during the same months in 2018. The groups were matched on 83 characteristics known before vaccination, and each group contained 36 460 people. In the 2017 cohort, 98.6% received the live vaccine. In the 2018 cohort, 93.5% received the recombinant vaccine.
Over seven years, the authors tracked ischemic heart disease, in which the heart muscle receives insufficient blood; ischemic stroke, in which blood flow to part of the brain stops; and heart failure, in which the heart pumps blood less effectively. According to the authors’ calculations, participants in the later cohort spent 9% more time without any of these diagnoses. The difference also persisted when ischemic heart disease and heart failure were analyzed separately.
During the year before vaccination, the same three diagnoses were recorded equally often in the main groups, and the groups used preventive care at similar rates. The authors also conducted a calendar period check by comparing recipients of the tetanus, diphtheria, and pertussis vaccine during the same months of 2017 and 2018. In this comparison group, the time without a cardiovascular diagnosis was similar in both periods.
In an earlier study of dementia, the same research group used the transition between the vaccines as a natural experiment. The new article applied the same approach to cardiovascular diagnoses. The authors identify AS01, a component of the recombinant vaccine that enhances the immune response, as a possible link between immune activity and vascular health. In a study of another vaccine containing AS01, the proportions of monocyte subtypes, which are cells of the innate immune system, changed in healthy adults. Some changes in DNA regions that regulate gene activity persisted for up to six months. The authors of the current article suggest that similar immune changes may be associated with vascular health.