As the coronavirus pandemic still sweeps around the world with second waves already erupting in some countries, pharmaceutical companies and research institutes around the world are fast-tracking the development of COVID-19 vaccines. Some scientists say that vaccine trials and approvals take months or even years. However, US President Trump claims one will be available before the presidential election. So, when will we have a safe and effective vaccine? We tapped the knowledge of Johns Hopkins University's Dr. William Moss.