Vaccinations have been one of the greatest public health achievements of the twentieth century, credited with extending global life expectancy, reducing premature mortality and morbidity, and reducing healthcare costs. May 8, 2020, marked the 40th anniversary of smallpox eradication - recent proof that vaccines have prevented millions of deaths each year since its invention. This heralded success of vaccines can often mean it is a victim of its own success as more people decide against immunizing their children. The Public Health Insight Team discusses how vaccine hesitancy poses a threat to public health and the potential re-emergence of previously controlled vaccine-preventable diseases.Follow us on Instagram, Twitter, and Facebook. We would love it if you shared your thoughts with us through direct message on your social media platform of choice or by emailing us at  ThePublicHealthInsight@gmail.com. Icon made by Smashicons from www.flaticon.com