Kevin Vilaca from South West Ontario Veterinary Services,Does IAV Sow Vaccination Affect Infection In Pigs At Weaning?

Vaccination is the cornerstone of control of Influenza   A   Virus   (IAV)   in   swine populations.  The  control  of  IAV  in  the growing pig population starts with control in  the  breeding  herd. University  of  Minnesota researchers  wanted  to  assess  the  effect  of  sow vaccination on IAV infection in pigs at weaning in a cohort  of  52  breeding  herds.  The  herds  were voluntarily enrolled according to their IAV history, sow vaccination protocol and monitored during a six month  period  as  a  prospective  longitudinal  study. On each herd, nasal swabs were collected monthly from 30 pigs at weaning and tested for IAV by RT-PCR.

The researchers found the following:

  • IAV  was  detected  in  25%  (75/305)  of  the monthly sampling events
  • IAV  was  detected  in  15%  (458/3050)  of  pools that  were  tested.
  • There  were 9,150  individual nasal swabs that were subsequently pooled with 3 individual nasal swabs/pool.
  • IAV infections in pigs at weaning were lower in vaccinated  herds  compared  to  non-vaccinated herds
  • There  was  no  significant  difference  between prefarrow and whole herd vaccination protocols. Prefarrow and whole herd vaccination protocols reduced the odds of groups testing IAV positive at weaning in comparison with no vaccination

Take Home Message

  • These  results  demonstrated  that  sow  herd vaccination  is  a  useful  strategy  for  control  of influenza infections in pigs at weaning.
  • It is interesting that both the prefarrowing booster approach  and  the  blitz  whole  herd  vaccination approach were effective in controlling the rate of infection in weaned pigs.

Submitted by Kevin Vilaca, DVM

Ref:  Fabian  O  Chamba  Pardo  ,  Matthew  W  Allerson  ,  Marie  R Culhane,  Robert  B  Morrison  ,  Peter  R  Davies  ,  Andres  Perez, Montserrat Torremorell Effect of influenza A virus sow vaccination on  infection  in  pigs  at  weaning:  A  prospective  longitudinal study Transbound  Emerg  Dis  .  2020  Jul  11.  doi:  10.1111/tbed.13688.