Effect of Killed PRRSV Vaccine on Gut Microbiota Diversity in Pigs

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

Researchers Fangfeng Yuan, Jaishree Sharma, Som G. Nanjappa, Christopher A. Gaulke, and Ying Fang from the University of Illinois at Urbana Champaign present information on the impact of killed PRRSV vaccine on the gut microbiome in today’s Science Page.


Non-infectious PRRSV vaccines, including killed virus vaccines, are safer to use but the vaccine efficacy needs to be improved. New strategies are needed to develop innovative non-infectious PRRSV vaccines. Microbiota – the collection of trillions of bacteria, viruses, and other microorganisms that inhabit the various body sites of the animal – are proposed to play key roles in the development and modulation of immune systems, which could contribute to the host responses to vaccination. The interaction between PRRSV infection/vaccination and microbiota could provide novel insights into microbiota-targeted intervention strategies and vaccine development.


To evaluate the effectiveness of a killed PRRSV vaccine and explore potential interactions between gut microbiota and improved outcomes and vaccine-induced immunity in a nursery pig model.

Materials and Methods

Fecal microbial communities were longitudinally assessed in three groups of pigs (vaccinated/challenged with PRRSV, unvaccinated/challenged with PRRSV, and unvaccinated/unchallenged) before and after vaccination and after viral challenge. Composition of the fecal microbiome in all groups of pigs was determined by 16s rRNA gene amplification and next-generation sequencing on fecal swab samples. Microbial community diversity and composition were analyzed using DADA2 and R statistical software.  


1. Significant effects of viral challenge and vaccination on both taxonomic richness and community diversity of the gut microbiota were observed. 

2. Vaccination with killed PRRSV vaccine incompletely protects pigs against viral impacts on the microbiome. 

3. The abundances of several microbial taxa correlated with the level of viral load and the host T-cell immune response.

Conclusions and Implications

This study highlights the potential roles of gut microbiota in the response of pigs to vaccination, which may pave the road for the development of novel strategies to enhance vaccine efficacy.

Figure 1. Relative microbial abundance of fecal microbiota in genus
level. Genus level fecal microbial composition of all piglets at 0 dpv, 35
dpv, and 45 dpv was calculated. The legend on the right represents
each individual microbial genus in different colors. The top two genus
include Clostridium in light blue and Lactobacillus in dark blue.
Figure 2. Alpha diversity of fecal microbiota. Boxplot depicting species
richness (a) and Shannon diversity index (b) were graphed using all
group pig samples from 0 dpv, 35 dpv, and 45 dpv (10 dpc). Legend on
the right shows four factors including control, vaccine, virus, and virus
vaccine. Black dot in panel b indicates a statistical outlier (i.e.,
Quartile 3 + 1.5 × Interquartile range).

The full paper can be found at: https://www.mdpi.com/1999-4915/14/5/1081 

Corresponding Authors: Christopher A. Gaulke cgaulke@illinois.edu and Ying Fang yingf@illinois.edu 

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