Subjects: VACCINATION of children; INFLUENZA vaccines; ANTIBODY titer
Record details
Subjects: INFLUENZA epidemiology; INFLUENZA vaccines; INFLUENZA A virus
Subjects: INFLUENZA vaccines; OLDER people; CLINICAL trial registriesHONG Kong (China)
Subjects: VIRUS diseases; INFLUENZA A virus; INFLUENZA viruses
Subjects: INFLUENZA epidemiology; EPIDEMIOLOGICAL research; INFLUENZAHONG Kong (China)