Nationalistic behavior by governments may exclude some countries from gaining access to COVID-19 vaccines and cost the global economy up to $1.2 trillion a year in GDP, according to a new study from the not-for-profit research organization RAND Europe. If countries demonstrate 'vaccine nationalism' - prioritizing their own citizens and insisting on first access to vaccines by signing deals directly with pharmaceutical companies and hoarding supplies - this could mean that, by initially immunizing only their own populations, they incur economic penalties for themselves as well as the wider global population. The study's macroeconomic analysis shows that, as long as the virus is not under control in all regions of the world, there will continue to be a global cost associated with COVID-19 and its prolonged negative impact on certain economic sectors. Even if only the lowest-income countries were denied equal access to a vaccine and all other countries managed to immunize their populations against the virus, it could still cost the global economy $153 billion a year in GDP terms. The US would lose $16 billion a year, the EU $40 billion a year, the UK $5 billion a year, China $14 billion a year, and other high-income countries collectively $39 billion a year.