The protective effect (or neutralising antibody levels) of all vaccines tends to drop with time. That is why the government is encouraging booster shots for those who have already had their Covid-19 vaccination. International Medical University (IMU) Infectious Disease Consultant and Head, Division of Medicine, School of Medicine, Prof James Koh says this should not come as a surprise as most vaccines have boosters. It is not unique to the Covid-19 vaccine. It’s important to get the booster shot, which essentially“reawakens”our immune system to start producing antibodies. Learn more about this at Get Jabbed, Stay Protected (New Straits Times, 25 January 2022).