$Pfizer (PFE.US)$ The Pfizer jab is "the hardest to deliver ...

$Pfizer (PFE.US)$ The Pfizer jab is "the hardest to deliver given ultra-cold chain and special syringe requirements", Gavi says in its internal document. It is also "the hardest to plan for as these (donated vaccines) often come with earmarking and little notice or in a staggered manner and in small volumes and with short shelf lives". Wealthy countries donating COVID-19 vaccines with a relatively short shelf life has been a "major problem" for COVAX, a WHO official said last week, as many doses were wasted.