Oral vaccine trial for wild deer in the US

The United States Department of Agriculture – Wildlife Services (USDA-WS) is conducting a trial to deliver an oral bovine tuberculosis (TB) vaccine to wild deer in Michigan. The vaccine is being deployed through vaccine delivery units placed strategically in crop fields where deer are frequently seen.

The trial began in late February and is expected to run until next month at 12 to 15 selected sites in part of Alpena. The vaccine units consist of alfalfa and molasses cubes containing an edible sphere with liquid BCG, a weakened strain of Mycobacterium bovis.

BCG has been used for over a century to protect children from TB and is a widely used vaccine globally. The vaccine delivery units are left in place for up to two days, monitored, and any unconsumed vaccines are retrieved.

After a few weeks, the USDA-WS will harvest deer from the trial area for analysis by the State of Michigan and USDA. The Michigan Department of Natural Resources (DNR) has stated that deer will not be vaccinated beyond this trial until broader testing is conducted.

There are no physical markers to indicate which deer have consumed the vaccine. Previous studies have shown that BCG is not found in deer muscle tissue, with protection lasting up to four months. The DNR assures that vaccination sites are not near homes and any leftover vaccine units will be collected.

Overall, the trial aims to assess the effectiveness of oral TB vaccination in wild deer and its long-term impact on wildlife health.