BACKGROUND: Australia introduced a funded shingles vaccination program for older 
adults in November 2016, administered predominantly in primary care clinics. 
MedicineInsight, a nationally representative primary care database, was used to 
investigate the risk of pre-specified outcomes following live attenuated herpes 
zoster vaccine (ZVL) in Australia.
METHODS: Individuals aged 70-79 years who received ZVL between 1 November 2016 
and 31 July 2018 were identified from MedicineInsight. The self-controlled case 
series (SCCS) method was used to estimate the seasonally-adjusted relative 
incidence (RI) of seven pre-specified outcome events (injection site reaction 
(ISR) [positive control], burn [negative control], myocardial infarction (MI), 
stroke, rash, rash with an antiviral prescription, and clinical attendance) 
during a plausible post-vaccination at-risk window compared with times distant 
from vaccination. Sensitivity analyses examined the effect of common concomitant 
vaccinations and restriction to first outcome events.
RESULTS: A total of 332,988 vaccination encounters among 150,054 individuals 
were identified during the study period; over 2 million clinical attendances 
were observed. There was an increased RI of ISR in the seven days following ZVL 
(RI = 77.4, 95% CI 48.1-124.6); the RI of clinical attendance (RI = 0.94, 95% CI 
0.94-0.95) and stroke (RI = 0.58, 95% CI 0.44-0.78) were lower in the 42 days 
following administration of ZVL compared to control periods. There was no 
evidence of a change in the RI of MI (RI = 0.74, 95% CI 0.41-1.33), rash 
(RI = 0.97, 95% CI 0.88-1.08), or rash with antiviral prescription (RI = 0.83, 
95% CI 0.62-1.10) in the 42 days following ZVL compared to control periods.
CONCLUSION: No new safety concerns were identified for ZVL in this study based 
on a novel, Australian primary care data source. An expected increased risk of 
ISR was identified; findings in relation to cardiovascular disease were 
reassuring but require confirmation using additional data, including hospital 
records.