Vaccine development for certain diseases has been a real challenge because of genetic diversity, the type of immune response needed (such as diseases that primarily require T cell protection), or other reasons. Examples of such diseases include malaria, TB, and COVID-19. The hope is that new technologies will enable the development of more effective vaccines against such pathogens.
Examples of newer technologies include:
- Nucleic acid-based vaccines: These would be able to be developed using the pathogen's genetic sequences without having to use the organism itself. Some of the COVID-19 vaccines already use an RNA platform.
- Viral vector vaccines: Such vaccines use a harmless recombinant virus whose genome is altered to express the target pathogen antigen. The benefit of such a vaccine would be that it would better mimic a real infection, but a possible issue would be if the person has already developed antibodies to the virus vector.
- Methods of delivery of the antigen: There are efforts to improve antigen delivery such as using liposomes, polymeric particles, as well as immunostimulating complexes. Also, delivery methods such as microneedle patches are under investigation.
In conclusion, though much progress has been made, vaccine efforts are still hampered by gaps in our knowledge of the intricacies of the immune response, as well as variations among individuals' immune responses.
