fbpx
Sign up now!
Don't show this again
Download the report!Continue to Site >
or wait 7 secs

Thank you for confirming your subscription!

(And remember, if ever you want to change your email preferences or unsubscribe, just click on the links at the bottom of any email.)

We’re glad you’re enjoying Pig Health Today.
Access is free but you’ll need to register to view more content.
Already registered? Sign In
Tap to download the app
X
Share
X

REPORTS

Collect articles and features into your own report to read later, print or share with others

Create a New Report

Favorites

Read Later

Create a new report

Report title (required) Brief description (optional)
CREATE
X
NEXT
PORK POULTRY
follow us


You must be logged in to edit your profile.

Favorites Read Later My Reports PHT Special Reports
Pig Health Today is equipped with some amazing (and free) tools for organizing and sharing content, as well as creating your own magazines and special reports. To access them, please register today.
Sponsored by Zoetis

Pig Health Today | Sponsored by Zoetis

.

PRRSV vaccine produces robust and lasting immune response when given to day-old piglets

A new study shows that piglets can mount a strong, specific and lasting immune response to porcine respiratory and reproductive syndrome virus (PRRSV) when vaccinated at 1 day of age.

Furthermore, the study demonstrates that vaccination does not produce potentially harmful inflammatory reactions in the young pigs, confirming the vaccine’s safety profile.

The study, which was conducted by Zoetis and published in Porcine Health Management, looked at immune responses to PRRSV following vaccination of day-old pigs with a modified-live vaccine based on PRRSV-1, a European strain of the virus.1

“PRRSV is known to interact with the host’s immune system. Some strains can induce a slow and weak innate immune response and a delayed adaptive immune response,” explained Monica Balasch, PhD, director of research and development at Zoetis and one of the study’s authors.

“Moreover, the immune system of the neonatal pig is not fully developed. This has created concerns about using live vaccines in young pigs, so we did this study to confirm whether pigs could safely and effectively mount an adequate immune response to PRRSV when vaccinated at 1 day of age.

“Our results confirm that pigs can be vaccinated on day 1 without impeding innate or adaptive immune development. This helps ensure the young pigs are protected from PRRSV early, before they enter a period of high risk.”

Study design

The study was conducted in 25 pigs born to PRRSV-seronegative sows. The pigs were vaccinated at 1 day of age by the intramuscular (n = 10) or intranasal (n = 10) route, or given saline (n = 5). Eighteen weeks later, the pigs were challenged with a PRRSV-1 field strain.

To characterize immune development, study investigators took blood samples at several points after vaccination and after challenge to measure levels of various immune molecules, known as cytokines, that are associated with the innate and adaptive arms of the immune system. The innate immune system is non-specific and provides animals with their earliest form of immune protection, Balasch explained. Meanwhile, the adaptive immune system — consisting of humoral and cell-mediated components — targets specific antigens and develops later in life.

Cytokines measured in the study included IL-8, IL-10, TNF-a and IFN-a. IFN-g-secreting cells and neutralizing antibodies (NA) to the vaccine strain were also measured.

Results

Results from the vaccinated pigs demonstrated:

  • Undetectable or low levels of pro-inflammatory cytokines IL-8 and TNF-a. Inflammation can be harmful to young pigs, so this finding reinforces the strong safety profile of the vaccine.
  • No production of IL-10, a cytokine that is known to interfere with innate immune response.
  • Consistent induction of IFN-a- and IFN-g-secreting cells. The presence of these cytokines following vaccination predicts the development of robust cell-mediated immune response later in life.
  • Induction of NA to the vaccine strain, an indicator of humoral immune response. After PRRSV challenge, there was a rapid boost in NA, indicating a priming effect of the vaccine.

Based on these findings, investigators concluded that piglets vaccinated at 1 day of age can develop innate, humoral and cell-mediated immune responses to the vaccine strain very early that are sufficient to protect them from an experimental challenge with a wild-type PRRSV strain.

A paradox and a ‘plus’

According to Balasch, the ability to safely and effectively vaccinate pigs on day 1 is both a paradox and a “plus” when it comes to PRRSV protection.

“It’s a paradox because day-old pigs generally have a reduced ability to respond to immunological stimulation compared to pigs of weaning age,” she noted.

“However, that was not the case with the vaccine used in our study. Despite the immaturity of their immune systems, the pigs vaccinated on day 1 were still able to mount an immune response that was adequate to clear the challenge virus when infected.”

The ability to vaccinate pigs at 1 day of age, rather than at weaning, has meaningful benefits, Balasch added.

“By vaccinating pigs on day 1, producers can ensure the pigs are protected at weaning, helping to close the gap between the loss of maternal immunity — usually around 3 to 4 weeks of age — and the onset of active immunity, 3 to 4 weeks after vaccination,” she explained.

“The earlier onset of protection we see with this live PRRSV vaccine, combined with the robust innate, humoral and cell-mediated responses we observed in our study, make it a reliable insurance policy against PRRSV as well as the costly secondary infections and production losses that are associated with it.”

 

To view the full study, click here.


1 Balasch, et al. Immune response development after vaccination of 1-day-old naïve pigs with a Porcine Reproductive and Respiratory Syndrome 1-based modified live virus vaccine. https://porcinehealthmanagement.biomedcentral.com/articles/10.1186/s40813-018-0112-7

 




Posted on November 26, 2019

tags: , ,
RELATED NEWS



You must be logged in to edit your profile.

Google Translate is provided on this website as a reference tool. However, Poultry Health Today and its sponsor and affiliates do not guarantee in any way the accuracy of the translated content and are not responsible for any event resulting from the use of the translation provided by Google. By choosing a language other than English from the Google Translate menu, the user agrees to withhold all liability and/or damage that may occur to the user by depending on or using the translation by Google.