Ingelvac Provenza®: Control of Influenza A Virus in Swine Calls for a Whole-Herd Approach

Control of Influenza A Virus in Swine Calls for Whole-Herd Approach

Introduction
Influenza A virus in swine (IAV-S) is considered to be one of the top 3 diseases threatening productivity in swine herds. IAV-S is hard to control on many farms because it can become endemic from the continuous birth and subsequent exposure of naïve piglets to resident IAV-S or as a result of the arrival of replacement female pigs with new IAV-S.^1-4

A whole-herd approach (WHA) has been used successfully as a key strategic approach to controlling porcine reproductive and respiratory syndrome (PRRS) virus infection within a population.⁵ The goal of WHA is to minimize exposure and maximize immunity of susceptible pigs.⁶ This approach is equally appropriate for IAV-S and can lead to the reduction or elimination of IAV-S endemicity and the impact of IAV-S in young pigs.

Objectives
of whole-herd
approach

Current IAV-S control
Even with homology of circulating strains, an approach that relies on killed vaccines to protect piglets through the transfer of maternal antibodies offers limited control of IAV-S. Current sow vaccination practices generally fail to control IAV-S transmission and can actually prolong the transmission period. As a result, endemic disease will persist because of continuous circulating IAV-S among young animals.⁷

Additionally, because transmission continues to be a factor, a control program that depends on vaccination solely of sows does not help to control either antigenic drift or IAV-S diversity.⁷

Why a whole-herd approach?
WHA aims to target the key at-risk populations primarily responsible for IAV-S transmission and circulation (farrowing units, the gilt development unit, and breeding and gestation barns). WHA leverages practices that decrease young pigs’ exposure to IAV-S, maximize their immunity to IAV-S, and limit the ability of new strains of IAV-S to enter the herd.^4,8-10

Implementation of WHA takes advantage of the fact that pigs are born free of IAV-S (ie, there is no vertical transmission from the sow).¹¹ It is imperative to capitalize on this opportunity by creating a window in which these young, naïve pigs can be given a strong foundation for IAV-S control. This control is achieved by following practices that minimize the IAV-S challenge in the farrowing house while simultaneously building broad immunity in the young pig.

Ingelvac Provenza® fits in a whole-herd approach
As an intranasal, live attenuated influenza vaccine for neonatal pigs, Ingelvac Provenza stimulates local mucosal immunity, offering protection at the site of natural IAV-S infection. Ingelvac Provenza provides broad cross-protection against the ever-evolving risk of IAV-S, through the nursery period and beyond.^12-14 Only Ingelvac Provenza protects the right animal, at the right time, by the right route—making it the ideal tool to use as part of a WHA.

For more information about WHA for IAV-S control, talk to your Boehringer Ingelheim representative or visit IngelvacProvenza.com.

References: 1. Brown IH. The epidemiology and evolution of influenza in pigs. Vet Mic. 2000;74:29046. 2. Corzo CA, Morrison RB, Fitzpatrick AM, et al. Risk factors for detecting influenza A virus in growing pigs. J Swine Health Prod. 2014;22(4):176–184. 3. Torremorell M, Allerson M, Corzo C, et al. Transmission of influenza A virus in pigs. Trans and Emerg Dis. 2012;59(Suppl 1):68–84. 4. Diaz A, Torremorell M. Dynamics of flu infection in sow farms. In: Allen D. Leman Swine Conference; September 15–18, 2012; St. Paul, MN. 5. Rathkjen PH, Dall J. Control and eradication of porcine reproductive and respiratory syndrome virus type 2 using a modified live type 2 vaccine in combination with a load, close, homogenise model: an area elimination study. Acta Vet Scand. 2017;59(1):4. 6. Whole herd approach maximizes immunity, minimizes transmission. National Hog Farmer website. https://www.nationalhogfarmer.com/print/28715. Accessed May 10, 2019. 7. Loeffen WLA, Heinen PP, Bianchi ATJ, et al. Effect of maternally derived antibodies on the clinical signs and immune response in pigs after primary and secondary infection with an influenza H1N1 virus. Vet Immunol Immunopathol. 2003;92(1-2):23–35. 8. Diaz A, Perez A, Sreevatsan S, et al. Association between influenza A virus infection and pigs subpopulations in endemically infected breeding herds. PLoS One. 2015;10(6):e0129213. 9. Diaz A, Marthaler D, Culhane M, et al. Complete genome sequencing of influenza A viruses within swine farrow-to-wean farms reveals the emergence, persistence, and subsidence of diverse viral genotypes. J Virol. 2017;91(18):e00745-17. 10. Abente EJ, Gauger PC, Walia RR, et al. Detection and characterization of an H4N6 avian-lineage influenza A virus in pigs in the Midwestern United States. Virology. 2017;511:56–65. 11. Van Reeth K, Brown IH, Olsen CW. Influenza virus. In: Diseases of Swine. Hoboken, NJ: Wiley-Blackwell; 2012:557–570. 12. Vincent AL, Ma W, Lager KM, et al. Efficacy of intranasal administration of a truncated NS1 modified live influenza virus vaccine in swine. Vaccine. 2007;25:7999–8009. 13. Janke BH. Influenza A virus infections in swine: pathogenesis and diagnosis. Vet Pathol. 2014;51:410–426. 14. Goodell C, Playter S, Fergen B, et al. Benefits of live attenuated influenza vaccination in neonatal commercial pigs, observed after challenge with contemporary IAV-S at 10 and 15 weeks of age. In: Proceedings from American Association of Swine Veterinarians Annual Meeting; March 9–12, 2019; Lake Buena Vista, FL.

Whole-Herd Approach

Control of Influenza A Virus in Swine Calls for Whole-Herd Approach

Objectivesof whole-herdapproach

Objectives
of whole-herd
approach