In this study, 340 pregnant women in the third trimester were randomly assigned to receive inactivated influenza vaccine or the 23-valent pneumococcal polysaccharide vaccine (control).

• 在这个研究中，340名孕妇在孕期第三个三个月中被随机的分配接受灭活流感疫苗或者23-价肺炎球菌多糖疫苗注射（对照）。