HI, My wife is 4 months pregnant woman, now she is suffering from fever and lower back pain. One day before she vomited from that time lower back pain is started. And I am scared it is a dengue fever or other. But 2 weeks before we consulted doctor for first trimester scan and she put injection name is not sure but it sounds like *fluvacine* something. So that injection is for vaccination or some other thing.