Photos: Covid-19 vaccines are providing hope that the pandemic is coming to an end. But mass immunization will be a huge feat, especially in low and middle-income countries. Startups like Nigeria's Gricd are trying to bridge the gap, providing portable cold boxes that can be transported to remote and rural areas. Hide Caption Photos: Gricd cold boxes are packaged securely, and equipped with monitoring devices that can detect their location, internal temperature and humidity. This creates a controlled environment to ensure the vaccine's efficacy. Hide Caption Photos: In sub-Saharan Africa, where 600 million people live off the grid, PEG Africa is helping to outfit rural health clinics with solar power, so that they can power vaccine refrigeration, as well as carry out other medical procedures that require energy.