There are a variety of speech-related symptoms that can be associated with apraxia, including: Difficulty stringing syllables together in the appropriate order to make words, or inability to do so. Minimal babbling during infancy. Difficulty saying long or complex words.
1 Understand that hepatitis B vaccination-induced protective antibodies can last for up to 15 years, but appear to fall off over time.
The minimal intervals for hepatitis B vaccine are at least 4 weeks between doses #1 and #2, at least 8 weeks between doses #2 and #3, and at least 16 weeks between doses #1 and #3. Since in your cases 16 weeks or more have elapsed since dose #1, you should schedule dose #3 to be given 8 weeks after dose #2.