Last-mile delivery is a logistic solution and the final step of a product's supply chain and delivery process to the end customers. It is this final step that determines if the product reaches the customer on time and safely. Recently, a new product had to make its way through this process – Covid-19 vaccines. Never in history has there been such urgency to get out billions of vaccine doses - safely and on time - to every part of the world. In the case of a Covid-19 vaccine dose, its last-mile delivery ends when it is injected into a recipient. Here’s a look at the challenges the vaccines had to overcome to get to their recipients. The challenges of last-mile delivery Over less than six months, the world was able to administer over a billion Covid-19 doses – but that was not easy. Getting the vaccines to the customers proved to be highly challenging for logistic companies, governments, and health organizations worldwide. 1. Vaccine spoilage: Vaccines have a shelf life, and they