Michaeleen Doucleff

One of the surprising aspects of the pandemic is that symptoms can linger months after infection. This syndrome has been called "long COVID," and it's had a profound impact on many people's lives.

Pandemic predictions have been made — and then things would change. But based on models and studies (including a 1980s test that squirted virus up human noses), researchers have a new endgame thesis.

The Johnson & Johnson booster is a big issue because people who received that vaccine may need a booster more urgently than those who received the Pfizer or Moderna, according to some experts.

That's how some scientists describe the findings of a series of studies looking at the antibodies created by individuals who were infected by the coronavirus and then had an mRNA vaccine.

So, how long does immunity last after two doses of the vaccine? Six months or so? And at that point, how much protection is left over?