Complex sentence: The pneumococcal vaccinations may not cover some of the other strains of pneumococcal bacterial present in other countries, and likewise its antibiotic resistance may also vary requiring a different choice of stand-by antibiotic.
Split into simpler sentences: The pneumococcal vaccinations may not cover some of the other strains of pneumococcal bacteria present in other countries. Likewise their antibiotic resistance may also vary, requiring a different choice of stand-by antibiotic.