Pfizer vets say vaccines are safe
Pfizer Animal Health veterinarians have taken issue with our story "Rethink MLV IBR Vaccines" (December, page 31). They say all of Pfizer’s Bovi-Shield Gold vaccines have been proven safe again and again since the label was approved in 2002. This includes the modified-live (MLV) infectious bovine rhinotracheitis (IBR) product.
If there were concerns, says Victor Cortese, director of cattle immunology for Pfizer, they were mainly due to inappropriate use. "There are extremely rare instances of abortion in ‘appropriately’ vaccinated heifers," he says.
"Experts would agree that giving an MLV IBR vaccine to a naive [unvaccinated] pregnant animal can cause an abortion," adds Gary Neubauer, a senior managing veterinarian with Pfizer.
IBR abortion storms can wipe out 25% to 60% of a calf crop. These often happen when herds are commingled or heifers of unknown health background are purchased.
"With the advent of Inforce 3 and our 16-month duration of immunity study for Bovi-Shield Gold, there is now an alternative way to rearrange protocols and avoid vaccinating pregnant animals," Neubauer says.
When Bovi-Shield Gold was given to pregnant dams in a 1,400-cow study, abortions were not statistically different from control cows given sterile water diluent. Controls averaged 2.2% abortions versus 2.3% for Bovi-Shield vaccinated animals.
The key, say Cortese and Neubauer, is to work with your veterinarian in establishing vaccine protocols for your herd. It’s also imperative to strictly follow the protocol.