Max Kozlov A health worker gives a fourth booster vaccination for COVID-19 to a person in Viña del Mar, Chile. Credit: Lucas Aguayo/Zuma Press/Avalon Confronted once again with waning immunity against SARS-CoV-2, health officials around the world are planning to roll out booster jabs in the next few months. But these booster campaigns might not have the come-one, come-all...