If this latest vaccine proves effective in humans, scientists say it would be easier to distribute, because it has a long shelf life and would not require refrigeration.

• 科学家说，如果能证明这种新疫苗对人也有效，那么分发疫苗就会比较容易，因为这种疫苗有效保存期比较长，而且不需要冷藏。