Pig Influenza Vaccine

Influenza in all mammalian species is caused by specific viruses that have the ability both to jump species and recombine to produce new strains that can then affect one or more species.  The close proximity of people, pigs and ducks in Chinese rural society provides a natural kitchen where the viruses can be brewed up. In recent years a new strain of influenza has emerged in people (initially in Mexico but now worldwide), which has been referred to in the popular press as “Swine Flu”, although it is categorised as Influenza A H1N1 09v (North America).  Whilst WHO declared it a  pandemic of influenza in people in June 2009, the virus has not been derived directly from pigs and in fact has shown the ability to operate as a reverse zoonosis – pigs have become infected from people.

Prior to 1985, Swine Influenza (SI) in pigs had not been seen clinically in the UK although subsequently investigation have shown that one specific strain – also derived from human beings (H3N2) – has been present in the pig population since 1968.  This strain was first detected as causing clinical disease in 1986, 1 year after the first SI cases caused by a  pig specific H1N1 strain.  Subsequently a new strain appeared in 1991/2 which was a recombinant of the H1N1 pig strain and an avian influenza strain and was designated H1 A/SW/195852/92.  Coming together with infection by PRRS (Blue Ear) this strain was particularly severe.  Furthermore through the 1990’s other strains such as H1N2 and H3N1 have been detected in pigs.


There are many causes of respiratory disease in pigs, including influenza. Among influenza types, only type A influenza viruses are known to infect pigs. Most of the influenza viruses circulating in swine are different from those circulating in people. When viruses that normally circulate in pigs infect humans, they are termed “variant” viruses.

At this time, there are three main flu viruses that circulate in U.S. pigs: H1N1, H1N2 and H3N2. These viruses do not usually infect people and are genetically different from the H1N1 and H3N2 viruses that commonly circulate in people. When the flu viruses circulating in pigs are very different from the human flu viruses causing illness in people, people may have little to no immune protection against the viruses circulating in pigs. Also, human flu vaccines probably would not offer protection against the viruses that are found in pigs. Flu viruses commonly infect pigs and pig herds and can result in high rates of illness among pigs, but few deaths.

Signs of influenza in pigs include:

  • Coughing (“barking”)
  • Sneezing
  • High fevers
  • Breathing difficulties
  • Discharge from the nose
  • Going off feed

Features of Pig Influenza Vaccine

SwIV vaccines share similarities with the killed vaccines for humans, but there are essential differences too. While the human vaccines generally contain purified viral surface antigens without adjuvant, most SwIV vaccines are whole virus preparations with an oil-based adjuvant. And unlike for the human vaccines, antigenic dose and vaccine strains are not standardized for SwIV vaccines (Van Reeth and Ma, 2013). In keeping with the antigenic and genetic differences between SwIV in Europe and in North America, the vaccines for each geographical region are produced locally and contain entirely different strains.

The most widely used vaccine on the European market is trivalent and contains avian-like H1N1, human-like H1N2 and H3N2 SwIV from around 2000 in combination with a carbomer adjuvant. An oil-adjuvanted bivalent vaccine is also frequently used. It is based on an avian-like swine H1N1 and a human H3N2 strain isolated more than 35 years ago. Similar vaccines in the US contain representative strains of up to 3 different H1 SwIV lineages, and one or 2 H3N2 lineages. A monovalent vaccine based on the 2009 pandemic H1N1 virus was recently launched in both continents.

Benefits of Pig Influenza Vaccine

Swine influenza, or swine flu, typically refers to a variant of an influenza virus that normally circulates in pigs but can infect humans. The respiratory virus can cause illness in humans and is responsible for previous pandemics. However, swine flu vaccines are a safe and effective way to help prevent complications from the virus.

Prices of Pig Influenza Vaccine


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