Infant shots when is the best time for an immune response: 6 weeks, 8 weeks, or 2 calendar months? my ped says that 6 weeks is too early. we'd prefer to get them before two calendar months around 8 weeks. what is the best time?

Hard to say: Too early & the immature immune system of an infant doesn't get as much response. Too late and you risk exposure & infection. In the US the routine starts at 2 months, but six weeks is fine, based primarily on the need to get in and get it done when you can. I don't see much benefit in worrying about this specific. They need the full series over the first yr to be protected.