A handful of drone-delivery startups want to help transport Covid-19 vaccines from distribution facilities to health centers, vying for a logistical role in what is likely to be a sprawling and complex undertaking. Several of these businesses recently have entered into medical delivery partnerships with drug companies and retailers--including Merck & Co. and Walmart Inc.-- that could help position them to take part in the high-profile effort to distribute Covid-19 vaccines.

After what has started to feel like a boundless eternity of wearing masks, bathing in hand sanitizer, and dodging people in the grocery store, many of us have been left thinking: what would a COVID-19 vaccine look like?