Last year during the mosquito epidemic my flock was infected with fowl pox.. I did not loose any of my girls but I did end up immunizing the flock and having a few in my chicken hospital of a bathroom. When researching I discovered that some people warned that from now on i would have to vaccinate each new bird that hatched or new members brought in. There was also others who said that all of that was not true..... Today..... almost a year later.... I notice that my new Rooster has the pox... So there you go... so I quickly vaccinated all the new birds. I do not want a repeat of last year. I was thinking that this proves something... but it also could be that he simply got it because he is not immune and the mosquitos are out again.