How long does the pertussis vax actually last?

The pertussis vaccine is only good for three years, after which immunity wanes substantially, new research confirms.

A Canadian study including almost 6000 people found almost no protection beyond seven years despite the modern acellular vaccine showing high early effectiveness.

The odds of pertussis increased by 27% each year that passed after vaccination, dramatically dropping after four years, the researchers found.

Those primed with acellular vaccine had 2.2 times higher odds of disease than those primed with the previously used whole-cell vaccine, the results show. (Acellular vaccine is used in Canada the US, Australia, New Zealand and much of Europe.)

The results support recent observational studies from the US and suggest the need to reconsider pertussis vaccination and “spur vaccine development”.