<qa>  What is the presence of a moderate or severe illness with or without fever?- Acute disease at the time of enrolment. Acute disease is defined as the presence of a moderate or severe illness with or without fever. All vaccines can be administered to persons with a minor illness such as diarrhoea, mild upper respiratory infection with or without low-grade febrile illness, i.e. oral axillary temperature 37.5C or 37 C in Czech Republic. 