Spanish flu pandemic was caused by a particularly virulent strain of influenza virus. It infected 500 million people, caused around 50 million deaths, and its impact was so severe that global life ...
2023 — A new study of the strain of influenza A responsible for the 2009 H1N1 pandemic -- pdm09 -- shows that the virus has passed from humans to swine about 370 times since 2009, and subsequent ...