See if you want to go, then you can appear for the MSc Biotechnology and in your course work you can specialize the course in the following subjects, in order to explore your interest in Vaccines:

• Immunology
• Bioinformatics
• GENETICAL ENGINEERING & GENOMICS

After your Master's you can do PhD in Biotechnology and can do research in Vaccinology which will help you to properly specialize in the field of Vaccines.

To know more about MSc Biotechnology visit the link below:

https://www.careers360.com/courses/msc-in-biotechnology

I hope this answer helps. All the very best for your future endeavors!