From storage to transport, hurdles to getting Covid vaccine to N Koreans

North Korea has not responded to offers of aid from South Korea and international vaccine-sharing programmes, but prefers U.S.-made Moderna and Pfizer over China's Sinovac orUK's Astrazeneca shots

As North Korea battles its first known COVID outbreak, a lack of storage, chronic power shortages and inadequately trained medical staff pose acute challenges to inoculating its 25 million people - even with outside help, analysts said.

North Korea has not responded to offers of aid from South Korea and international vaccine-sharing programmes, but prefers U.S.-made Moderna and Pfizer over China's Sinovac or British-Swedish Astrazeneca shots, according to South Korean officials.

Both the U.S. vaccines rely on technology known as mRNA, and require super-cold storage. Sinovac or AstraZeneca vaccines can be transported and stored at normal refrigerator temperatures.

"Moderna and Pfizer vaccines require