There was no higher risk of heart attack for recipients of the two-dose hepatitis B cytosine phosphoguanine adjuvant vaccine (Heplisav-B) compared to the three-dose hepatitis B vaccine with an aluminum hydroxide adjuvant (Engerix-B), a prospective study found.
Among nearly 70,000 adults who received at least one hepatitis B vaccine dose, type 1 acute myocardial infarctions (MIs) occurred at a rate of 1.67 per 1,000 person-years for those who received the two-dose vaccine and 1.86 per 1,000 person-years for recipients of the three-dose vaccine, which met noninferiority criteria (adjusted HR 0.92, one-sided 97.5% CI ∞ to 1.32, P<0.001), reported Katia Bruxvoort, PhD, of the University of Alabama at Birmingham, and colleagues in JAMA.
Clinical trials showed that the two-dose vaccine led to significantly greater seroprotection, which was also achieved earlier than the three-dose vaccine. However, one clinical trial found the two-dose vaccine was also associated with a greater number of MIs, Bruxvoort’s group noted. Of those, participants who experienced acute MIs had greater cardiovascular risk factors at baseline, while the events occurred randomly without a “temporal relationship to vaccination,” they added.
The FDA approved Heplisav-B in November 2017 but required a postmarket trial at Kaiser Permanente Southern California (KPSC) due to safety concerns surrounding the risk of MI and immune-mediated diseases.
For their study, the researchers examined electronic health records data from 69,625 adults who received at least one hepatitis B vaccine dose at KPSC from Aug. 7, 2018 to Oct. 31, 2019. Those who received an index dose of the two-dose vaccine (n=31,183) or the three-dose vaccine (n=38,442) at the internal medicine or family medicine department of the integrated healthcare system were included. Excluded were those undergoing dialysis.
To assess the risk of type 1 acute MI, participants were followed up until the first occurrence of an acute MI, disenrollment from KPSC, death, or after 13 months.
Inverse probability treatment weighting adjusted for socio-demographics and clinical characteristics. Two cardiologists confirmed acute MI events, which could be adjudicated by a third cardiologist.
Median patient age was 49, just over half were men, and roughly half were Hispanic. In the year prior to their index dose of a hepatitis B vaccine, 58-59% had diabetes, 41-42% had dyslipidemia, and 42-44% had a Charlson Comorbidity index score of 1. Nearly one-quarter had obesity, while only 0.4-0.5% had had an acute MI. Nearly two-thirds were on cardiovascular disease medication in the year prior to their index vaccine dose. Nearly half (47-49%) received other vaccines concomitantly with their index dose.
At follow-up, 52 of 74 potential acute MI events were confirmed type 1 MIs in the two-dose vaccine group versus 71 of 128 in the three-dose vaccine group.
The authors acknowledged limitations to the data, including the potential for misclassifying vaccine exposures or acute MI diagnoses.
Zaina Hamza is a staff writer for MedPage Today, covering Gastroenterology and Infectious disease. She is based in Chicago.
This study was supported by Dynavax Technologies, the manufacturers of HEPLISAV-B.
Bruxvoort reported support from Gilead, GlaxoSmithKline, Moderna, Pfizer, and Seqirus.
Coauthors reported support from ALK, Amgen, the Centers for Disease Control and Prevention, Genentech, GlaxoSmithKline, Gilead, Merck, Moderna, Novartis, Novavax, Pfizer, Seqirus, and ViiV Healthcare.