Initial tests in mice of a potential COVID-19 vaccine delivered via a fingertip-sized patch have shown it can induce an immune response against the new coronavirus at levels that might prevent infection, US scientists said on Thursday. Researchers around the world are working to develop potential treatments or vaccines against the respiratory disease that has killed nearly 47,000 people and infected almost a million in just a few months. A team at the University of Pittsburgh School of Medicine in the United States said they were able to move quickly in developing a potential COVID-19 vaccine after working on other coronaviruses that cause Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS). “These two viruses, which are closely related to SARS-CoV-2 (the new coronavirus causing the COVID-19 pandemic), teach us that a particular protein, called a spike protein, is important for inducing immunity against the virus,”