A case-control study to assess the effectiveness of pertussis vaccination during pregnancy on newborns, Valencian community, Spain, 1 March 2015 to 29 February 2016

In the Valencian Community (Spain), the programme of maternal pertussis vaccination during pregnancy started in January 2015. The objective of this study was to estimate in this region the vaccine effectiveness (VE) in protecting newborns against laboratory-confirmed pertussis infection. A matched case–control study was undertaken in the period between 1 March 2015 and 29 February 2016. Twenty-two cases and 66 controls (+/− 15 days of age difference) were included in the study. Cases were non-vaccinated infants < 3 months of age at disease onset testing positive for pertussis by real-time PCR. For every case three unvaccinated controls were selected. Odds ratios (OR) were calculated by multiple conditional logistic regression for association between maternal vaccination and infant pertussis. Other children in the household, as well as mother- and environmental covariates were taken into account. The VE was calculated as 1 − OR. Mothers of five cases (23%) and of 41 controls (62%) were vaccinated during pregnancy. The adjusted VE was 90.9% (95% confidence interval (CI): 56.6 to 98.1). The only covariate in the final model was breastfeeding (protective effect). Our study provides evidence in favour of pertussis vaccination programmes for pregnant women in order to prevent whooping cough in infants aged less than 3 months.

Changing epidemiology of Infant Meningococcal Disease after the introduction of meningococcal serogroup C vaccine in Italy, 2006-2014

BACKGROUND

In Italy, the incidence of Invasive Meningococcal Disease (IMD) was around 0.28 per 100,000 over the last years. Since the risk IMD is usually high among infants aged less than 1 year, we decided to evaluate the trend of IMD cases reported between 2006 and 2014 in this age group. In particular, the study aim was to describe the main characteristics of IMD cases in infants following the introduction of MCC vaccine (2005) and to estimate the number of cases which are potentially preventable through early vaccination.

METHODS

The National Surveillance System of Bacterial Meningitis was established in 1994 and in 2007 was extended to all invasive bacterial diseases. Clinical data and isolates and/or clinical samples are collected from hospitalized patients throughout the country. IMD cases are reported by clinicians to the local health authorities, and samples are sent to the Reference Laboratory at the Istituto Superiore di Sanità for further characterization and storage at -80°C. In particular, serogroup identification is obtained by agglutination with commercial antisera or by multiplex PCR.

RESULTS

The annual incidence for infants <1 year old remained rather stable of 3.6 per 100,000, with several upward and downward oscillations and a peak in 2010. The incidence of IMD among infants was more than 10 times higher than the overall rate of IMD observed in Italy. Finally, serogroup B was more frequently detected among infants aged <1 year, accounting for 65% of the total (p<0.01).

CONCLUSIONS

During the study period, IMD incidence reported among infants aged less than one year old was 10 times higher than the overall rate, and serogroup B was the most commonly detected over time. The long-term impact of meningococcal C conjugate vaccine and the effect of the introduction of meningococcal B vaccination among infants need to be evaluated.

Management and prevention of pertussis infection in neonates

Despite the fact that universal immunization against pertussis led to a dramatic decrease in the incidence and mortality in high-income countries, it has left a window of vulnerability for newborns. Although specific guidelines concerning management of neonatal whooping cough have not yet been developed, the present review summarizes the main available recommendations on diagnostic work-up and treatment of neonatal pertussis. Additionally, new prevention strategies are explored, including the use of an additional booster dose of vaccine to adolescents and adults, vaccination of healthcare workers, immunization of household contacts and caregivers (cocooning strategy), vaccination of pregnant women and, finally, neonatal immunization with novel vaccines. These strategies are analyzed and discussed in terms of efficacy, safety and cost-effectiveness.