Antitoxins for diphtheria and tetanus decline more slowly after vaccination with DTwP than with DTaP: A study in a Chinese population

Although the observed protection rates for diphtheria and tetanus were sufficient to prevent an outbreak at present, the means levels of diphtheria and tetanus antitoxins decreased with increasing age; therefore, booster vaccinations at 7 and 12 years of age would be strengthened in Gaobeidian city, China.