Benjamin Cowling from the University of Hong Kong discusses the duration of protection from coronavirus vaccines and the potential need for booster shots. He estimates that the protection may last for more than a year, possibly two or three years, but new variants may require updated vaccines. Cowling also talks about the impact on travel and tourism, with countries like Europe and the United States possibly opening up to anyone by summer, while parts of Asia, such as Hong Kong and Singapore, may remain closed for a longer period.