Antibody persistence at 18-20 months of age and safety and immunogenicity of a booster dose of a combined DTaP-IPV//PRP∼T vaccine compared to separate vaccines (DTaP, PRP∼T and IPV) following primary vaccination of healthy infants in the People's Rep

► Pre-booster antibody persistence was good for each valence. ► Strong response to each antigen following booster in 2nd year of life. ► Booster vaccination is safe and well tolerated. ► Data support the use of DTaP-IPV//PRP∼T as a booster vaccine in China.