Chapter 17
Attenuation Methods for Live Vaccines
Dipasree Hajra, Akshay Datey, and Dipshikha Chakravortty
Abstract
Vaccination was developed by Edward Jenner in 1796. Since then, vaccination and vaccine development
research has been a hotspot of research in the scientific community. Various ways of vaccine development are
successfully employed in mass production of vaccines. One of the most successful ways to generate vaccines
is the method of virulence attenuation in pathogens. The attenuated strains of viruses, bacteria, and
parasites are used as vaccines which elicit robust immune response and confers protection against virulent
pathogens. This chapter brings together the most common and efficient ways of generating live attenuated
vaccine strains in viruses, bacteria, and parasites.
Key words Live attenuated strains, Gene inactivation, Mutagenesis, Irradiation, microRNA
1 Introduction
Live attenuation of pathogens is one of the major modes of vaccine
development strategies. Pathogen attenuation refers to inactivation
of the virulence factors which leads to loss of disease-causing ability
[1]. However, the ability of the pathogen to induce a potent
immune response is highly conserved. A perfect live attenuated
vaccine is the one which has completely lost its virulence but has
all the pathogen associated molecular patterns (PAMPs) intact.
Once administered, these live attenuated strains of bacteria, virus,
or parasites do not cause a disease but elicit a strong immune
response as a consequence to its intact PAMPs. The immune
response can either be humoral or cell mediated. Both the
responses generate a memory response which serves as a protective
mechanism against invading pathogens.
However, they retain their capacity of replication and transient
growth within the host. Attenuation is mostly achieved by growing
the organism under unnatural growth conditions for prolonged
periods so that it becomes better suited to grow in the abnormal
Blaine A. Pfeifer and Andrew Hill (eds.), Vaccine Delivery Technology: Methods and Protocols, Methods in Molecular Biology,
vol. 2183, https://doi.org/10.1007/978-1-0716-0795-4_17, © Springer Science+Business Media, LLC, part of Springer Nature 2021
Dipasree Hajra and Akshay Datey contributed equally to this work.
331
Attenuation Methods for Live Vaccines
Dipasree Hajra, Akshay Datey, and Dipshikha Chakravortty
Abstract
Vaccination was developed by Edward Jenner in 1796. Since then, vaccination and vaccine development
research has been a hotspot of research in the scientific community. Various ways of vaccine development are
successfully employed in mass production of vaccines. One of the most successful ways to generate vaccines
is the method of virulence attenuation in pathogens. The attenuated strains of viruses, bacteria, and
parasites are used as vaccines which elicit robust immune response and confers protection against virulent
pathogens. This chapter brings together the most common and efficient ways of generating live attenuated
vaccine strains in viruses, bacteria, and parasites.
Key words Live attenuated strains, Gene inactivation, Mutagenesis, Irradiation, microRNA
1 Introduction
Live attenuation of pathogens is one of the major modes of vaccine
development strategies. Pathogen attenuation refers to inactivation
of the virulence factors which leads to loss of disease-causing ability
[1]. However, the ability of the pathogen to induce a potent
immune response is highly conserved. A perfect live attenuated
vaccine is the one which has completely lost its virulence but has
all the pathogen associated molecular patterns (PAMPs) intact.
Once administered, these live attenuated strains of bacteria, virus,
or parasites do not cause a disease but elicit a strong immune
response as a consequence to its intact PAMPs. The immune
response can either be humoral or cell mediated. Both the
responses generate a memory response which serves as a protective
mechanism against invading pathogens.
However, they retain their capacity of replication and transient
growth within the host. Attenuation is mostly achieved by growing
the organism under unnatural growth conditions for prolonged
periods so that it becomes better suited to grow in the abnormal
Blaine A. Pfeifer and Andrew Hill (eds.), Vaccine Delivery Technology: Methods and Protocols, Methods in Molecular Biology,
vol. 2183, https://doi.org/10.1007/978-1-0716-0795-4_17, © Springer Science+Business Media, LLC, part of Springer Nature 2021
Dipasree Hajra and Akshay Datey contributed equally to this work.
331