New chicks vaxd, flock is not

No.

The vaccine loses effectiveness each day after hatch. By now it is way too late.

 

No, (old flock)

It be like vaccinating for chicken pox after the human kid had it.

Yes, (new chicks)

Vaccinating birds is the oz of prevention vs pound of cure. If your chicks got mareks, it be a bad day and your options would suck.


It's considered a baby chick disease so the grown ones have already weathered the storm


In general, I love vaccines. I rather lose a bird to a vaccine than a disease. It's more I rather try something then not be able to do anything. Plus it's unlikely to lose one to a vaccine.

 

Marek's is not simple so there is no catch-all simple answer.

Would it HURT to vaccinate your older birds with the Marek's HVT Vaccine (the kind us hobbyists can get in the mail)? No, as long as they are all well and not suffering from ill heath.

Would it HELP to vaccinate your older birds with said vaccine? Probably not. The vaccine loses much of its effectiveness after the chicks are 36 hours old. The vaccine is only able to be as effective as it is when administered within 36 hours of life, due to the way a chick's immune system works. These chicks should then be kept in quarantine from all other chickens for a minimum of 2-3 weeks for best chances of the vaccine helping to build an immune response.

If you are concerned, ask what vaccine they use where you are buying your chicks from. If they use HVT, this is a different serotype (species) of the virus, and despite some misinformation out there, this vaccine can NOT cause your vaccinated birds to spread Marek's.

Of course, be sure that your source for your new chicks is clean and reputable, and hatches/raises chicks in isolation from other chickens, otherwise you do run a risk of the virus coming in on the chicks if they are accidentally exposed before they are sent to you. Even vaccinated chicks can shed the virus, IF they are exposed to it previously.

 

Yea it takes 2 weeks for it to work