I like the Virashield vaccines if you can find them and would not use a live on the calves if they are still on the cow. Just not worth the risk, calves are a good price. I called Elanco and talked to one of their vets. He said they had a buy out and they also lost their stock for the vaccine and are having to regrow it. He didn't say Covid but think it had something to do with it. He said anything with somnus was in short supply but by June 24 they should be back to normal on getting vaccines out.