Vaccines are responsible for some of the greatest public health triumphs ever, including the eradication of naturally occurring smallpox and the almost complete removal of polio from the planet. It is a cost-effective healthcare intervention with significant economic impact
Recombinant protein vaccines
Recombinant protein vaccines are subunit vaccines that utilise only a small part of the pathogen and elicit an immune response against them1.
Advantages2,3:
- Antigen has a well-defined composition
- No risk of pathogenicity
- Synthesis and purification can be scaled up in a cost-effective manner
- Almost negligible side effects
- Safer than live-attenuated and inactivated killed vaccines
Recombinant Platform Technology
Conjugate vaccines
Conjugate vaccines are composed of pathogen-specific capsular polysaccharides (CPS) conjugated to an immunostimulatory protein carrier4.
Advantages5:
- Enhance the poor immunologic responses
- Reduce asymptomatic carriage of the bacteria
- Safe and immunogenic in young infants
- Induces long-term memory
Conjugate Platform Technology
Combination vaccines
A combination vaccine contains two or more antigens that is designed to protect against two or more diseases or against one disease caused by different strains or serotypes of the same organism.6
Advantages7:
- Fewer injections
- Increased compliance
- Better vaccination coverage
- Allows incorporation of new vaccines into immunization schedules
Combination
Fractional Dose vaccines
Fractional dose vaccine is the one that uses a fraction of the standard dose of a vaccine to trigger the same protective immune responses as the standard dose.8
Advantages:
- Cost effective9
- Less side effects9,10
- Expand vaccine availability and coverage10
- Improving vaccination coverage11
Fractional Dose
1. Matić Z, Šantak M. Current view on novel vaccine technologies to combat human infectious diseases.Appl Microbiol Biotechnol.2022;106(1):25-56. doi:10.1007/s00253-021-11713-0
2. Bill RM. Recombinant protein subunit vaccine synthesis in microbes: a role for yeast?. J PharmPharmacol. 2015;67(3):319-328.doi:10.1111/jphp.12353.
3. Wang M, Jiang S, Wang Y. Recent advances in the production of recombinant subunit vaccines in Pichia pastoris. Bioengineered. 2016;7(3):155-165. doi:10.1080/21655979.2016.1191707.
4. Stark JC, Jaroentomeechai T, Moeller TD, et al. On-demand biomanufacturing of protective conjugate vaccines. Sci Adv. 2021;7(6):eabe9444.Published 2021 Feb 3. doi:10.1126/sciadv.abe9444.
5. Kumraj G, Pathak S, Shah S, et al. Capacity Building for Vaccine Manufacturing Across Developing Countries: The Way Forward. Hum VaccinImmunother. 2022;18(1):2020529. doi:10.1080/21645515.2021.2020529.
6. DT-Based Combined Vaccines. ttps://www.who.int/teams/health-product-policy-and-standards/standards-and-specifications/norms-and-standards/vaccine-standardization/dt-based-combined-vaccines [accessed 15th April 2025]
7. Skibinski DA, Baudner BC, Singh M, O’Hagan DT. Combination vaccines. J Glob Infect Dis. 2011;3(1):63-72. doi:10.4103/0974-777X.77298
8. DT-Based Combined Vaccines. ttps://www.who.int/teams/health-product-policy-and-standards/standards-and-specifications/norms-and-standards/vaccine-standardization/dt-based-combined-vaccines [accessed 15th April 2025]
9. New global vaccine trial launched to evaluate fractional COVID-19 booster shots https://cepi.net/new-global-vaccine-trial-launched-evaluate-fractional-covid-19-booster-shots [accessed 15th April 2025]
10. Moreira Puga MA, Dias de Oliveira R, Vieira da Silva P, et al. Immunogenicity and reactogenicity of fractional vs. full booster doses of COVID-19 vaccines: a non-inferiority, randomised, double-blind, phase IV clinical trial in Brazil. Lancet Reg Health Am. 2025;44:101031. Published 2025 Feb 22. doi:10.1016/j.lana.2025.101031
11. Wu JT, Peak CM, Leung GM, Lipsitch M. Fractional dosing of yellow fever vaccine to extend supply: a modelling study. Lancet. 2016;388(10062):2904-2911. doi:10.1016/S0140-6736(16)31838-4