Conservationists fear that if two doses of the vaccine are needed to immunize the global population than half a million sharks would subsequently die. Several pharmaceutical companies are using squalene, an oil from shark liver, in the development of potential COVID-19 vaccines. This has conservationists scared that the mass production of a COVID-19 vaccine could decimate the global shark population. According to the World Health Organization (WHO) there are 176 potential COVID-19 vaccines in clinical and preclinical evaluation in which 17 of them use adjuvants. “The industries stand to profit immensely from having a global vaccine,” Brendl said.