Johnson & Johnson single-shot vaccine: 10 factsUltra cold chain not requiredWHO senior adviser Bruce Aylward said that the Johnson & Johnson vaccine, which does not require an ultra cold chain, was "even better suited to some of the countries that are worst-hit, affected by the pandemic".While the vaccine needs to be stored at -20 degrees, which may prove challenging in some environments, it can be kept for three months at 2-8°C and it has a long shelf life of two years.First from WHOThe vaccine from Johnson & Johnson is the first to be listed by WHO as a single dose regimen, which should facilitate vaccination logistics in all countries.Studies have shown that the Johnson & Johnson vaccine is 66% effective in protecting any cases of.