Vaccination recommendations for pregnant people travelling overseas

With international travel on the rise following pandemic restrictions, the number of pregnant travellers is likely to proportionally increase. Recent published data suggest most pregnant travellers seek pre-travel advice from their maternity and primary care providers. With these data, it is important to provide maternity and primary care providers with guidelines and resources to help aid safe, informed, and timely delivery of vaccinations prior to travel. Vaccination for travel during pregnancy is fundamental in mitigating maternal and fetal communicable disease morbidity and mortality. This clinical perspective provides an overview of the indications, safety, and recommendations for pre-travel vaccines in pregnancy.

Study Protocol for Preventing Early-Onset Pneumonia in Young Children Through Maternal Immunisation: A Multi-Centre Randomised Controlled Trial (PneuMatters)

Background: Preventing and/or reducing acute lower respiratory infections (ALRIs) in young children will lead to substantial short and long-term clinical benefits. While immunisation with pneumococcal conjugate vaccines (PCV) reduces paediatric ALRIs, its efficacy for reducing infant ALRIs following maternal immunisation has not been studied. Compared to other PCVs, the 10-valent pneumococcal-Haemophilus influenzae Protein D conjugate vaccine (PHiD-CV) is unique as it includes target antigens from two common lower airway pathogens, pneumococcal capsular polysaccharides and protein D, which is a conserved H. influenzae outer membrane lipoprotein. Aims: The primary aim of this randomised controlled trial (RCT) is to determine whether vaccinating pregnant women with PHiD-CV (compared to controls) reduces ALRIs in their infants' first year of life. Our secondary aims are to evaluate the impact of maternal PHiD-CV vaccination on different ALRI definitions and, in a subgroup, the infants' nasopharyngeal carriage of pneumococci and H. influenzae, and their immune responses to pneumococcal vaccine type serotypes and protein D. Methods: We are undertaking a parallel, multicentre, superiority RCT (1:1 allocation) at four sites across two countries (Australia, Malaysia). Healthy pregnant Australian First Nation or Malaysian women aged 17-40 years with singleton pregnancies between 27⁺⁶ and 34⁺⁶ weeks gestation are randomly assigned to receive either a single dose of PHiD-CV or usual care. Treatment allocation is concealed. Study outcome assessors are blinded to treatment arms. Our primary outcome is the rate of medically attended ALRIs by 12-months of age. Blood and nasopharyngeal swabs are collected from infants at birth, and at ages 6- and 12-months (in a subset). Our planned sample size (n = 292) provides 88% power (includes 10% anticipated loss to follow-up). Discussion: Results from this RCT potentially leads to prevention of early and recurrent ALRIs and thus preservation of lung health during the infant's vulnerable period when lung growth is maximum. The multicentre nature of our study increases the generalisability of its future findings and is complemented by assessing the microbiological and immunological outcomes in a subset of infants. Clinical Trial Registration: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=374381, identifier: ACTRN12618000150246.

A Vaccine Against Group B Streptococcus: Recent Advances

Group B streptococcus (GBS) causes a high burden of neonatal and infant disease globally. Implementing a vaccine for pregnant women is a promising strategy to prevent neonatal and infant GBS disease and has been identified as a priority by the World Health Organisation (WHO). GBS serotype-specific polysaccharide – protein conjugate vaccines are at advanced stages of development, but a large number of participants would be required to undertake Phase III clinical efficacy trials. Efforts are therefore currently focused on establishing serocorrelates of protection in natural immunity studies as an alternative pathway for licensure of a GBS vaccine, followed by Phase IV studies to evaluate safety and effectiveness. Protein vaccines are in earlier stages of development but are highly promising as they might confer protection irrespective of serotype. Further epidemiological, immunological and health economic studies are required to enable the vaccine to reach its target population as soon as possible.

Maternal Immunization and Antenatal Care Situation Analysis (MIACSA) study protocol: a multiregional, cross-sectional analysis of maternal immunization delivery strategies to reduce maternal and neonatal morbidity and mortality

INTRODUCTION

Maternal immunization (MI) with tetanus toxoid containing vaccine, is a safe and cost-effective way of preventing neonatal tetanus. Given the prospect of introducing new maternal vaccines in the near future, it is essential to identify and understand current policies, practices and unmet needs for introducing and/or scaling up MI in low-income and middle-income countries (LMICs).

METHODS AND ANALYSIS

The Maternal Immunization and Antenatal Care Situation Analysis (MIACSA) is a mixed methods, cross-sectional study that will collect data in four phases: (1) a review of global databases for selected health indicators in 136 LMICs; (2) a structured online survey directed at Maternal, Newborn and Child Health and Expanded Programme on Immunization focal points in all 136 LMICs; (3) semistructured telephone interviews of 30 selected LMICs and (4) 10 week-long country visits, including key informant interviews, health facility visits and focus group discussions. The principal analyses will assess correlations between the various aspects of MI delivery strategies and proxy measures of health systems performance related to vaccine-preventable disease control. The primary outcome will be a typology of existing MI delivery models, and secondary outcomes will include country profiles of child and maternal health indicators, and a MI gaps and needs analysis.

ETHICS AND DISSEMINATION

The protocol was approved by the WHO Ethics Review Committee (ERC.0002908). The results will be made available in a project report and submitted for publication in peer-reviewed journals that will be shared broadly among global health decision-makers, researchers, product developers and country-level stakeholders.

Respiratory syncytial virus seasonality and its implications on prevention strategies

With maternal and infant vaccines against respiratory syncytial virus (RSV) in development, it is timely to consider how the deployment of these vaccines might vary according to local RSV disease seasonality. In temperate regions RSV infection is predictably limited to a period of 3 to 5 months, while in tropical regions disease seasonality is often both more variable and more prolonged. Accordingly, in tropical regions a year-round immunisation schedule for both maternal and infant immunisation might be appropriate. In contrast, in temperate regions the benefit of year-round maternal immunisation would be heavily dependent on the duration of protection this provided, potentially necessitating a strategy directed at children due to be born in the months immediately prior to the RSV season. This review will consider the impact of seasonality on maternal and infant immunisation strategies against RSV, and the potential of an alternative approach of passive immunisation for all infants immediately prior to the RSV season.

Antenatal pertussis vaccination: Are we implementing best evidence into practice?

Maternal immunisation is the most effective strategy to reduce infant morbidity and mortality from pertussis infection, and is now standard of care in many countries, including Australia. However, uptake cannot be guaranteed unless the barriers to implementing programs locally are understood. Education and resources for antenatal care providers, embedding vaccination within antenatal care, and provision of culturally appropriate information for pregnant women are integral to a successful antenatal vaccination program.

Factors influencing women's attitudes towards antenatal vaccines, group B Streptococcus and clinical trial participation in pregnancy: an online survey

OBJECTIVES

To explore factors influencing the likelihood of antenatal vaccine acceptance of both routine UK antenatal vaccines (influenza and pertussis) and a hypothetical group B Streptococcus (GBS) vaccine in order to improve understanding of how to optimise antenatal immunisation acceptance, both in routine use and clinical trials.

SETTING

An online survey distributed to women of childbearing age in the UK.

PARTICIPANTS

1013 women aged 18-44 years in England, Scotland and Wales.

METHODS

Data from an online survey conducted to gauge the attitudes of 1013 women of childbearing age in England, Scotland and Wales to antenatal vaccination against GBS were further analysed to determine the influence of socioeconomic status, parity and age on attitudes to GBS immunisation, using attitudes to influenza and pertussis vaccines as reference immunisations. Factors influencing likelihood of participation in a hypothetical GBS vaccine trial were also assessed.

RESULTS

Women with children were more likely to know about each of the 3 conditions surveyed (GBS: 45% vs 26%, pertussis: 79% vs 63%, influenza: 66% vs 54%), to accept vaccination (GBS: 77% vs 65%, pertussis: 79% vs 70%, influenza: 78% vs 68%) and to consider taking part in vaccine trials (37% vs 27% for a hypothetical GBS vaccine tested in 500 pregnant women). For GBS, giving information about the condition significantly increased the number of respondents who reported that they would be likely to receive the vaccine. Health professionals were the most important reported source of information.

CONCLUSIONS

Increasing awareness about GBS, along with other key strategies, would be required to optimise the uptake of a routine vaccine, with a specific focus on informing women without previous children. More research specifically focusing on acceptability in pregnant women is required and, given the value attached to input from healthcare professionals, this group should be included in future studies.