Monitoring Interest in Herpes Zoster Vaccination: Analysis of Google Search Data

Using analysis of online search data, this study aimed to provide insight into trends and potential reasons for interest in herpes zoster (HZ or shingles) vaccination following the United States (US) Food and Drug Administration's approval of a new recombinant subunit vaccine on October 20 2017. There have been low coverage rates with the live attenuated vaccine (Zostavax), ranging from 12-32% of eligible patients receiving the HZ vaccine. Many possible contributing factors to the low vaccination rate have been proposed, including high cost, a lack of consensus on vaccine recommendation, waning efficacy, supply issues, and general lack of awareness of the vaccine and its benefits. According to these researchers, influences on general awareness and interest in the HZ vaccine are poorly understood, and if known they could be utilised in designing more effective public health efforts to increase HZ immunisations.

Internet search data were queried from the Google Health application programming interface from 2004-2017. Seasonality of normalised search volume was analysed using wavelets and Fisher's g test. The search terms "shingles vaccine", "zoster vaccine", and "zostavax" all exhibited significant periodicity in the fall months (P<.001), which appeared in part to be related to utilisation of Medicare benefits, covaccination with the influenza vaccine, and advertising campaigns (e.g., by Merck, as in the ad shown above). Furthermore, in the US, United Kingdom, and Canada, a spike in search interest occurred in each country for vaccine-related terms soon after a recommendation by a health-related governmental organisation was broadcast. With this in mind, it may be helpful to increase vaccine production or clinical stocks in anticipation of the increase in vaccine interest caused by these announcements so as to avoid stockouts.

"Given previous issues with HZ vaccine availability and coverage, these trends may help predict when to increase supply of the new recombinant subunit vaccine to meet changes in demand, and when to increase awareness to improve coverage."