As COVID-19 cases surge despite mass vaccination, it's time to focus on the vulnerable

The COVID-19 pandemic is an era-defining, international emergency impacting the global economy, politics and countless individual lives. People living with cancer have increased risk of hospitalisation and mortality from COVID-19. There are limited data regarding vaccine efficacy in people with cancer, with lack of empirical evidence to guide vaccine strategy in cancer patients fostering uncertainty. Vulnerable groups, for whom vaccination protection may be attenuated, now carry the greatest burden of risk amongst the population. The cancer community needs to reconsider the potential on-going impact of COVID-19 and develop and plan new programs of work to mitigate it. Multiple potential future scenarios now exist, ranging from full protection from COVID-19 for cancer patients via herd immunity to viral evolution for vaccine resistance and increased virulence. Defining those most vulnerable to COVID-19 post-vaccination will require largescale data and evidence to comprehensively identify factors that reduce vaccine efficacy. Once identified, protecting these groups through transmission and mortality risk reduction will become paramount. As the pandemic progresses, "protecting the vulnerable"may enable a return to normal for the majority, whilst still protecting individuals living with and beyond cancer who already live with the challenges of having a cancer diagnosis.