Related Experiment Video
Updated: Apr 5, 2026
08:52
Evaluation of Host-Pathogen Responses and Vaccine Efficacy in Mice
Published on: February 22, 2019
11.5K
The Need for Evolutionarily Rational Disease Interventions: Vaccination Can Select for Higher Virulence
1Integrative Biology, University of California Berkeley, Berkeley, California, United States of America; Biosciences, University of Exeter, Penryn Campus, Penryn, United Kingdom.
Plos Biology
|August 26, 2015
Summary
Vaccination can inadvertently drive the evolution of more virulent infectious diseases. A study on Marek's disease in chickens shows vaccinated birds survive longer, shedding more of the virus and increasing its harmfulness.
Area of Science:
- Evolutionary biology
- Infectious disease dynamics
- Veterinary medicine
Background:
- Evolutionary theory predicts that interventions like vaccination can sometimes select for increased pathogen virulence.
- Understanding these evolutionary responses is crucial for effective disease control strategies.
Purpose of the Study:
- To empirically test the theory that vaccination can lead to the evolution of more virulent infectious agents.
- To investigate the impact of vaccination on the virulence and transmission dynamics of Marek's disease virus.
Main Methods:
- Empirical study involving vaccination of chickens against Marek's disease.
- Monitoring host survival, virus shedding, and transmission in vaccinated and unvaccinated populations.
- Analysis of evolutionary changes in pathogen virulence.
Main Results:
- Vaccination against Marek's disease favored the evolution of higher pathogen virulence.
- Vaccinated hosts survived longer, allowing for increased virus shedding and transmission.
- Unvaccinated hosts experienced rapid mortality, limiting virus transmission.
Conclusions:
- This study provides empirical evidence that vaccination can drive the evolution of increased pathogen virulence.
- Interventions aimed at controlling infectious diseases must consider potential evolutionary consequences.
- Findings highlight the importance of integrating evolutionary principles into disease management and public health strategies.
More Related Videos
Related Concept Videos
01:51Vaccinations
54.0K
Overview
54.0K
01:21Vaccines
49
Vaccines are among the most effective tools in preventive medicine, designed to prepare the immune system to recognize and combat infectious agents. By introducing antigens—substances that the immune system identifies as foreign—vaccines stimulate an adaptive immune response that leads to immunological memory. This immunological memory enables the body to mount a faster and more effective response upon future exposures to the actual pathogen.Vaccines can be categorized based on the...
49
01:28Infectious Diseases and Their Occurrence
58
Infectious diseases appear in populations through various transmission patterns, influenced by pathogen characteristics, population immunity, environmental conditions, and social behavior. Understanding these patterns is essential for effective public health surveillance and intervention. These categories—sporadic, outbreak, epidemic, pandemic, and endemic—help frame the nature and scope of disease events.Sporadic diseases occur irregularly and infrequently, without a predictable...
58
01:16Transduction
2.7K
Among the three main modes of HGT—transformation, conjugation, and transduction—transduction is unique in that it is mediated by bacteriophages, or bacterial viruses.Transduction occurs in two ways. Generalized transduction occurs during the lytic cycle of a bacteriophage infection. In this process, bacteriophages infect bacterial cells, replicate within them, and ultimately cause cell lysis, releasing newly assembled virions. Occasionally, random fragments of the bacterial genome...
2.7K
01:29Microorganisms in Medicine and Therapeutics
1.4K
Microorganisms play a fundamental role in vaccine development, gene therapy, and therapeutic production. Their biological properties are harnessed to advance medicine and public health. Beyond immunization, microorganisms contribute to gut health, antibiotic synthesis, and genetic disease treatment.Live Attenuated and Inactivated VaccinesLive attenuated vaccines, such as the measles, mumps, and rubella (MMR) vaccine, utilize weakened forms of pathogens to closely resemble natural infections.
1.4K
00:36Viral Mutations
40.8K
A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material...
40.8K