Saving a trillion dollars with a universal coronavirus vaccine

What if we had a vaccine that protected against all major illness-causing coronaviruses?

The authors of An Advanced Market Commitment to Incentivize a Universal Coronavirus Vaccine Before the Next Variant find that a few billion dollars in the form of an advanced market commitment could stimulate the development of such a vaccine. Just counting averted deaths alone, it could be worth $1.08 trillion in value — likely far more than would be seen for monoclonal antibodies or continued reliance on COVID variant-specific boosters.

With an advanced market commitment, no money would have to be spent unless someone produced an effective product. So what are we waiting for?