Booster shot against diphtheria, pertussis, tetanus, and polio at 4-6 … stockbot 0 249 2021.09.29 19:52 http://vietnamnews.vn/society/1049893/booster-shot-against-diphtheria-… + 4 https://vietnamnews.vn/rss/society.rss + 2 Parents should not fail to provide their children with a diphtheria - pertussis - tetanus - polio booster shot amid the COVID-19 scramble, according to the Vietnam Association of Preventive Medicine.