Bringing vaccines to all parts of the world is crucial in ending the COVID-19 pandemic, and this will begin by securing enough doses for everyone. But even if enough vaccines are procured, other problems arise such as storage and distribution. We all saw how personal protective equipment (PPE) was in short supply last year at the onset of the pandemic and we are now seeing vaccines facing similar logistical bottlenecks such as production backlogs and shipping constraints today. However, delays in vaccine distribution are much harder to deal with because of one major complication: the cold chain. Most vaccines are temperature sensitive and they require transportation in extremely chilled environments--from warehouses, vehicles to boxes and storage areas--to ensure that they don't perish before they're administered.

The instructions upon getting a first dose of COVID-19 vaccine are clear: People should get the second shot three or four weeks later. But things get a lot murkier when it comes to actually getting an appointment to meet that deadline. As more Los Angeles County residents than ever receive their first doses, tightening vaccine supplies and online scheduling problems are hampering their ability to finish the two-dose vaccination process. On Thursday, potentially thousands of people had their vaccine appointments postponed after the Ralphs supermarket chain -- a large vaccine distributor -- said the county's Department of Public Health, at the request of state officials, had "recovered" 10,000 doses previously intended for scheduled appointments, according to emails obtained by The Times. A Ralphs spokesperson said only first-dose customers were affected, but it only added to the confusion.