Fear, social responsibility, or vulnerability - which is the main driver of seasonable influenza vaccination in times of the pandemic? Our study using first-hand survey data from the Australian Bureau of Statistics shows that none of these factors explains conclusively Australians who had the flu vaccination in 2020 due to COVID19 only. It was Australians who had higher education, without chronic health conditions, those in employment, fully covered by health insurance, living with families who reported statistically higher rates of flu vaccination due to COVID19 only. By contrast, people with one or more chronic health issues, single people without support reported statistically lower rates of seasonal influenza immunisation. Similar results are reported in the study of flu vaccination in countries like Canada, where among Canadians aged over 65, it was populations of higher education, married, in better health conditions (non-smokers), higher household income who reported consistently, statistically higher rates of flu vaccination between 2000-2019. The Australian survey data collected during the pandemic provided further evidence of flu vaccination as a risk-aversion health measure by low-risk populations - a social behavioural phenomenon observed across countries, ages, in normal circumstances or health crises. We interpreted our finding from the hypothesized human propensity to be risk-averse (chose to be vaccinated) when the perceived probability of an improvement over their status quo after vaccination was high (the certainty effect); and human tendency to be risk-seeking (chose not to be vaccinated) when the perceived probability of an improvement post-immunisation was low (the possibility effect). The higher rates of risk-averse behaviours (chose to be vaccinated) among people in better education, socio-economic and health conditions, and the lower rates of risk-seeking behaviours (chose not to be vaccinated) among people with chronic health issues and those living alone suggest that flu vaccination was perceived by low-risk populations as an effective risk-aversion measure leading to better outcomes of higher certainty; by contrast, flu vaccination was perceived by high-risk populations as a health measure of higher uncertainty, not aiding in improving their status quo as the implicit reference point, according to the Prospect Theory as applied in the study of people’s health behaviours.