kittens nursing after first shots

Question
I had a stray female cat bring her five tiny kittens onto my front veranda.  I brought them all in at about 5 weeks. (I'm guessing}  I took the kittens in for their first shots at a save cats organization.  Someone said be sure not to let the mother nurse them or the shots would be null and void.  I kept "Mom" away for 4 days then gave in, they were all happy.  
Is letting the kittens nurse a little really responsible for making the needle null and void?  Appreciating your response.

Answer
Darlene,

There is absolutely no issue with the kittens nursing on their mom after their vaccines... I had a kitty who was a single kitten in a litter nurse til he was well over a year old which included his vaccines and neuter. It is best for mom and the babies if the babies stay with mommy til they are at least 12 weeks old - kittens raised this way have fewer behavioural issues on average and are far less likely to be surrendered to a shelter later in life due to behavioural issues. The person who gave you this information most likely misunderstood maternal antibodies - these are the antibodies passed from mommy to babies through the breast milk, however they do not interfere with vaccines. Some veterinarians will recommend vaccinating at an early age to ensure that the maternal antibodies don't have a chance to wear off leaving the babies vulnerable to diseases prevented by vaccination especially when mom's vaccine status is unknown. If you have any further questions or concerns, please feel free to contact me again at any time - I'm more than happy to help in any way that I can.

Kind regards,

Ali