Vaccine Confidence in the Online Environment Open Access

Swart, Rachel Elizabeth (2017)

Permanent URL:


Background: In recent years, parents have become more concerned about the potential for an adverse reaction to a vaccine than vaccine-preventable diseases. This is contributing to the increase in unvaccinated children. The internet has changed the vaccine landscape with the ability to disseminate rapidly both accurate and inaccurate information about vaccines. The internet has influenced parents and has led them to either have high, low or no confidence in vaccines. From December 2014 to April 2015, there was a measles outbreak in California that led to a multiple state outbreak where the exposure originated from Disneyland in California. By February 11, 2015, there were 125 cases of measles (Zipprich, 2015). The purpose of this study was to therefore understand the online information environment in this context and its potential influence on vaccine attitudes, knowledge, and information-seeking patterns.

Methods: To better understand of what people used internet search engine queries for, from looking at California and the United States during the 2014-2015 measles outbreak, Google Trends and Google Correlate were used. Google Correlate was used to find search patterns that related to trends about vaccine confidence and the measles outbreak. Google Trends was used to form graphs based on ten of the terms from Google Correlate.

Results: Google Trends graphs for the United States and the state of California were similar. Although the spikes for searches either started earlier or continued to be searched for a longer period of time in California. Google Trends related queries were similar to Google Correlate searches. These searches surrounded the issues of the 2014-2015 measles outbreak. Google Correlate searches were more confined to wanting to know more about vaccines, as well as being more specific with the Measles Mumps and Rubella vaccine. There were also some searches that pertained to the anti-vaccination movement.

Conclusion: "Infodemiology" is when search engine queries are used as a form of surveillance. Using search engine queries and social media as a form of surveillance can assist with monitoring of a potential outbreak of an infectious disease (Woo, 2016). In the future, the use of Google Trends along with social media can act as an early form of surveillance for infectious diseases. This form of surveillance has already been used for seasonal influenza and should be put to use to track other potential infectious disease outbreaks (Kelly, 2013).

Table of Contents

Table of Contents

Chapter 1-Background 1

Background 1

Purpose Statement 8

Research Questions 8

Significance 8

Chapter 2- Literature Review 9

The impact of vaccines 9

What is vaccine confidence and vaccine hesitance 10

Vaccine confidence 10

Vaccine hesitance 11

What is vaccine refusal 13

Parental media exposure and under/un-vaccination 14

California measles outbreak case study 15

History of measles in the United States prior to the California outbreak 15

The California measles outbreak 16

Aftermath of the California measles outbreak 17

Assessment of internet usage trends 18

Google Correlate 18

Google Trends 19

Chapter 3- Manuscript 20

Abstract 20

Introduction 21

Methods 23

Google search analysis 23

Results 24

Internet search activity around the California measles outbreak 24

Discussion 26

Limitations 30

Conclusion 31

Chapter 4- Conclusion and recommendations 32

Conclusion 32

Recommendations 33

Public health and policy implications 34

Reference 36

Appendix 41

List of Graphs and Tables for Chapter 3 41

Google Trends Graphs 41

Google Trends Related Queries Tables 51

Google Correlate Tables 67

Table of Terms 73

IRB Letter 74

About this Master's Thesis

Rights statement
  • Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.
  • English
Research Field
Committee Chair / Thesis Advisor
Partnering Agencies
Last modified

Primary PDF

Supplemental Files