Patent US5676977A is for AIDS, patent US8835624B1 is for H1N1, patents US7897744B2 and US8506968B2 are for SARS
Patents are often filed by individuals or groups to protect an invention. This prevents the invention from being commercially exploited by others without the patent owner’s consent. However, a patent can also be filed for products of nature like viruses and for other reasons apart from restricting the use of an invention. For example, public health agencies like the U.S. Centers for Disease Control and Prevention patent viruses to keep samples accessible to researchers, preventing a single party from monopolizing samples and restricting research efforts.