COVID-19 vaccine supply shortages are causing concerns in some countries about compromised immunity as the interval between first and second dose extends due to limited vaccine availability. Additionally, a longer delay between first and second doses may be beneficial, resulting in an increased antibody titre and enhanced immune response after the second dose. There is an excellent response to a second dose, even after a 10 month delay from the first.’Conversely, some countries are considering administering a third ‘booster’ dose in the future. Studying the impact of a third vaccine dose, the researchers found that antibody titres increased significantly with a third dose. ‘Here we show that a third dose of ChAdOx1 nCoV-19 is well tolerated and significantly boosts the antibody response.
