Vaccinating older chicks

[redholsteins]

I just now received my Marecks vaccine and Newcastle vaccine in the mail unfortunately my chicks are more than a day old and it recommends giving it at a day old. Can I still vaccinate them for this if they are going on about 5 weeks old and the other batch is 7 days old. Tried searching for the answer but couldn’t find specifics. They were on back order and than on top of that the mail hasn’t been reliable. Thank you in advance.

 

[abpatchy]

Difficult to say. You could still immunize for Mareks IF they had no contact with adult birds, their droppings or dust. Dust gets everywhere... so if they are in an brooder where an adult bird stayed for a while... or in with the chicken's general area, it is too late.
Newcastle thru the syringe or waterer? Over here we mostly vaccinate against Newcastle thru the waterer every 6 weeks. Because mine get coccidia immunization, the chicks are about 3 weeks before they get the Newcastle. Either way I would not give them 2 vaccinations at a time.