Pertussis has re-emerged as an important public health concern and replacement of older whole-cell vaccines (wP) by acellular pertussis vaccines (aP) is believed to be one of the reasons. In this study on non-human primates, it was found that those vaccinated with aP were protected from severe symptoms but not infection and readily transmitted B.Pertussis to contacts. Vaccination with wP and previous infection induced a more rapid clearance compared with naïve and aP-vaccinated animals. While all groups possessed robust antibody responses, T-cell memory suggested that aP vaccination induced a suboptimal immune response that was unable to prevent infection. These data provide a reasonable explanation for pertussis resurgence and suggest that attaining herd immunity will require the development of improved vaccination strategies that prevent B. pertussis colonization and transmission.

We frequently encounter patients reporting thoughts of death or suicide while we use standard depression questionnaires like Patient Health Questionnaire for depression (PHQ-9). In this study, electronic records from a large integrated health system were used to link PHQ-9 responses from outpatient visits to subsequent suicide attempts and deaths. Responses to item-9 of the PHQ-9 remained a strong predictor of suicide attempt. Cumulative risk of suicide death over one year increased from 0.03% among those reporting thoughts of death or self-harm ideation "not at all" to 0.3% among those reporting such thoughts "nearly every day". This excess risk emerged over several days and continued to grow for several months, indicating that suicidal ideation was an enduring vulnerability rather than a short-term crisis. This may be a very important diagnostic tool for all those involved in the care of children suffering from depression to prevent such suicidal behaviour.