Vaccine-Related Bills From 2011 to 2017 (IMAGE) Drexel University Caption This graph shows the overall number of proposed pro- and anti-vaccine bills proposed by state lawmakers between 2011 and 2017. Credit Drexel University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.