Can we stretch our COVID-19 vaccine supply to meet our public health objectives?

The COVID-19 pandemic has created an urgent need to manufacture and distribute vaccines rapidly and widely across the world. Currently, three products (two based on the mRNA platform from Pfizer- BioNTech, Moderna and one based on the adenoviral vector platform from AstraZeneca-Oxford) are being used under emergency-use authorization in vaccination programs around the globe.