A new oral vaccine for cholera has received prequalification by the World Health Organization (WHO) on 12 April. (1)
- The inactivated oral vaccine Euvichol-S has a similar efficacy to existing vaccines but a simplified formulation, allowing opportunities to rapidly increase production capacity.
Types of vaccines (2)
- Inactivated vaccines use the killed version of the germ that causes a disease. Inactivated vaccines usually don’t provide immunity that’s as strong as live vaccines. So several doses are needed over time (booster shots) in order to get ongoing immunity against diseases.
- Live-attenuated vaccines use a weakened (or attenuated) form of the germ that causes a disease. Because these vaccines are so similar to the natural infection that they help prevent, they create a strong and long-lasting immune response.
- mRNA vaccines make proteins in order to trigger an immune response. mRNA vaccines do not contain a live virus, here there is no risk of causing disease in the person getting vaccinated.
- Subunit, recombinant, polysaccharide, and conjugate vaccines use specific pieces of the germ—like its protein, sugar, or capsid (a casing around the germ). Because these vaccines use only specific pieces of the germ, they give a very strong immune response that’s targeted to key parts of the germ.
- Viral vector vaccines use a modified version of a different virus as a vector to deliver protection. Several different viruses have been used as vectors. Adenovirus is one of the viral vectors used in some COVID-19 vaccines being studied in clinical trials.
