The study design and analysis controlled for influence of potentially confounding trends, such as improvement of day-care carriage and decreasing prevalence of smoking during the study period.
Despite a reduction in pertussis among younger children and infants, rates of pertussis-related sickness and death remain high compared with rates for other vaccine-preventable diseases in England and Wales.
In recent years there have been a series of arguments and findings suggesting that Statins (HMG-CoA reductase inhibitors) which used widely to lower cholesterol levels may also be important in reducing the risk associated with severe infective conditions.