We're now finding out that the acellular vaccine's doesn't offer protection for as long. It does work well in the short term. But there was definitely a tradeoff in phasing out the whole-cell vaccine.
It had to go - It's a vaccine that would not be accepted in the societies we have in North America and Europe. As much pertussis as we're seeing now, we're still seeing in most places pretty good control in the very young. We're seeing lapsed immunity in school-age kids and we have to solve that. But those kids aren't dying.
The scientific community back in the 1990s felt that it had pertussis solved ... We're now seeing that we don't have a solution yet.