Viral immunologist Dr. Bridle;
The data suggest the ostriches experienced an outbreak of avian influenza, which was most likely introduced to the farm by wild birds, in which the virus is endemic. In the ostriches, the virus functionally behaved like a low pathogenic strain, based on the percentage of deaths. Ostriches that had been on the farm for more than several years did not get sick, suggesting that they had naturally acquired immunity, likely from a previous exposure to the virus. Newer members of the flock got sick and some died. Most of the sick ostriches recovered and returned to full health. This suggests that all of the remaining healthy flock had naturally acquired immunity. So, to execute healthy birds with gold-standard immunity in no way increases the safety of people or animals in the region. In fact, it does the opposite.
A flock with naturally acquired immunity creates a geographical location where the virus will either be stopped dead in its tracks, or will have great difficulty getting transmitted. Instead, the farmers will be allowed, if they so wish, to repopulate the farm with immunologically naive birds that will be highly susceptible to influenza viruses that can get re-introduced by the birds that forever migrate through the property. Absolutely nothing has been done or can be done about the carrier population of wild birds that spread the virus between continents. So, by failing to acknowledge the reality of naturally acquired immunity, the Canadian Food Inspection Agency has done the opposite of enhancing public safety. Their policy of ignoring this basic science has raised public risk through the removal of a flock that achieved the ultimate public health goal of herd immunity and allowing them to be replaced with highly susceptible birds.
Indeed, the Canadian Food Inspection Agency has documented multiple farms across the country in which their stamping out policy for avian influenza facilitated the repeated return of the disease when naive birds were introduced. Over just a few-year span, several farms were documented to have up to four repeat outbreaks. Let’s explicitly spell out what that looks like…
