I had my swine flu jab but have to go back for another one in 3 weeks.Am i at all covered till my next one?

The vaccination was called celvapan and i was wondering how much protection the first jab gives me until i recieve the second one.Does it give me any? or do i have to wait until i have my second jab before it starts protecting me. The pamdemrix vaccine is a one off jab but due to my circunstances i was required to have the celvapan vaccine. Any info would be greatly welcome.