Swine Flu: The Advantage of Being Older

Between exposure to H1N1 prior to 1957, coupled with immunity based on being immunized against swine flu in 1976, people who were at least toddlers in 1957 are rarely getting the current round of H1N1.

I had heard of the immunities from the `57 and earlier flus, but I had not read anything before that the `76 vaccine was now helping those who had received it.