Pregnancy and the postpartum period are associated with elevated risks to both mother and infant from infectious disease. Vaccination of pregnant women, also called maternal immunization, has the potential to protect pregnant women, foetuses and infants from several vaccinepreventable diseases. Maternal immunoglobulin G antibodies are actively transferred through the placenta to provide passive immunity to new-borns during the first months of life, until the time for infant vaccinations or until the period of greatest susceptibility has passed. Currently, inactivated influenza, tetanus, and pertussis vaccines are recommended during pregnancy in many countries, but other vaccines may also be administered to pregnant women when risk factors are present. Several new vaccines with a specific indication for use during pregnancy are under development (e.g. respiratory syncytial virus and group B streptococcus vaccines). Years of experience suggest that maternal immunization against influenza, tetanus or pertussis has an acceptable safety profile, is well tolerated, effective and confers significant benefits to pregnant women and their infants. This review describes the principles of maternal immunization and provides an update of the recent evidence regarding the use and timing of maternal immunization. Finally, the barriers preventing wider vaccination coverage and the current limitations in addressing these are also described (Supplementary Material). KEY MESSAGESMaternal immunization gives pregnant women greater protection against infectious diseases; induces high levels of maternal antibodies that can be transferred to the foetus; and helps protect new-borns during their first months of life, until they are old enough to be vaccinated. Pregnant women and new-borns are more vulnerable to infectious diseases than the overall population; nevertheless, vaccination rates are often low in pregnant women. This review provides an update of the recent evidence regarding the use and timing of maternal immunization and describes the barriers preventing wider vaccination uptake and the current limitations in addressing these. ARTICLE HISTORY

Introduction: Pertussis (whooping cough) is a vaccine-preventable disease; however, neither naturalnor vaccine-induced protection is lifelong. Although generally not severe in adults, pertussis can be associated with complications in patients with chronic conditions such as asthma or chronic obstructive pulmonary disease, and can be readily transmitted to more vulnerable populations, including neonates before they complete their primary vaccination. Furthermore, as the global population ages, the health and economic burden of the disease is expected to rise. Areas covered: A systematic literature review was conducted to ascertain the current epidemiological and financial burden of pertussis in older adults and to discuss the potential value of a booster vaccination in this population. Expert commentary: Our review indicates a considerable underestimation of the pertussis burden amongst older adults. Seroprevalence studies consistently demonstrate that the reported incidence may be much lower than the actual incidence. Tetanus toxoid-reduced diphtheria toxoid and acellular pertussis vaccines are immunogenic in older adults, induce high booster responses and are welltolerated. There is therefore a good rationale for the advocacy of booster pertussis vaccination throughout life to prevent pertussis infection and its transmission, especially in adults aged ≥50 years.

BackgroundCervical cancer (CC) is caused by persistent infection with high-risk (HR) human papillomavirus (HPV) types. In Saudi Arabia which has a population of 6.5 million women over the age of 15 years, approximately 152 new cases of CC are diagnosed and 55 women die from the disease annually. Nevertheless current epidemiological data for HPV in this population are limited. This study evaluated the prevalence and type distribution of HPV and documented the awareness of HPV infection and health-related behavior among Saudi and non-Saudi women attending routine examination.MethodsThis was an observational, epidemiological cross-sectional study conducted between April 2010 and December 2011 at three hospitals in Saudi Arabia. Cervical samples from women aged ≥15 years, who were attending routine gynecological examinations were collected and tested for HPV-DNA by polymerase chain reaction and typed using the SPF10 DEIA/LiPA25 system. Two questionnaires on health-related behavior and awareness of HPV infection were completed.ResultsA total of 417 women, mean age (standard deviation) 41.9 (±10.4) years, were included in the final analysis, of whom 77% (321/417) were Saudi nationals. HPV-DNA was detected in 9.8% women (41/417, 95% confidence interval [CI]: 7.1-13.1). The prevalence of any HR-HPV by age was: 25–34 years: 3.0%; 35–44 years: 4.5%; 45–54 years: 3.2%; >55 years: 10.9%. The most prevalent HR-HPV-types were: HPV-68/73 (5 cases); HPV-18 (4 cases); HPV-16 (3 cases). The most prevalent low risk (LR) types were HPV-6 (4 cases); HPV-42, HPV-53 and HPV-54 (2 cases each). The prevalence of HPV was higher among non-Saudi nationals vs. Saudi nationals (16.7% vs. 7.8%, P = 0.0234). No statistically significant risk factors were identified: 32.2% (101/314) women were aware of HPV and 89.9% (285/317) showed an interest in HPV vaccination.ConclusionThe overall prevalence of HPV was 9.8% in Saudi Arabia, but was higher in women over 55 years, as well as in non-Saudi nationals. These data provide a reference for public health authorities and may also help in determining future policies for the prevention of CC.Clinical trial registrationNCT01213459Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-014-0643-8) contains supplementary material, which is available to authorized users.

Introduction: Infants too young to be fully immunized are the most vulnerable to severe pertussis disease. To close this susceptibility gap, passive infant immunization through vaccination of pregnant women against pertussis was first introduced in 2011 in the United States and has been extended since then to more than 40 countries. Areas covered: We conducted two systematic literature searches to describe the worldwide burden of pertussis disease in infants <6 months of age since 2005, and the effectiveness and impact of maternal pertussis vaccination in preventing infant pertussis since 2011. Expert opinion: Pertussis disease incidence rates in infants aged <2-3 months were substantial in all countries with available data, exceeding 1000 cases per 100,000 population during outbreaks. Virtually all pertussis deaths occurred in this age group. Data from Africa, Eastern Mediterranean, and Asia were limited, but suggest a similar or higher disease burden than in Europe or the Americas. Estimates of effectiveness of second/third trimester pertussis vaccination in preventing pertussis disease in <2-3 months old infants were consistently high (69%-93%) across the observational studies reviewed, conducted in various settings with different designs. Maternal vaccination programs appear to be achieving their goal of reducing the burden of disease in very young infants.