Risk of transmission of vaccine-preventable diseases in healthcare settings

The decline of measles antibody titers in previously vaccinated adults: a cross-sectional analysis

The global reemergence of measles in 2018-2019 reinforces the relevance of high-coverage immunization to maintain the disease elimination. During an outbreak in the Sao Paulo State in 2019, several measles cases were reported in individuals who were adequately vaccinated according to the current immunization schedule recommends. This study aimed to assess measles IgG antibody seropositivity and titers in previously vaccinated adults. A cross-sectional study was conducted at CRIE-HC-FMUSP (Sao Paulo, Brazil) in 2019. It included healthy adults who had received two or more Measles-Mumps-Rubella vaccines (MMR) and excluded individuals with immunocompromising conditions. Measles IgG antibodies were measured and compared by ELISA (Euroimmun®) and chemiluminescence (LIASON®). The association of seropositivity and titers with variables of interest (age, sex, profession, previous measles, number of measles-containing vaccine doses, interval between MMR doses, and time elapsed since the last MMR dose) was analyzed. A total of 162 participants were evaluated, predominantly young (median age 30 years), women (69.8%) and healthcare professionals (61.7%). The median interval between MMR doses was 13.2 years, and the median time since the last dose was 10.4 years. The seropositivity rate was 32.7% by ELISA and 75.3% by CLIA, and a strong positive correlation was found between the tests. Multivariate analyses revealed that age and time since the last dose were independently associated with positivity. Despite being a single-center evaluation, our results suggest that measles seropositivity may be lower than expected in adequately immunized adults. Seropositivity was higher among older individuals and those with a shorter time since the last MMR vaccine dose.

Role of the National Immunisation Technical Advisory Groups in 13 European countries in the decision-making process on vaccine recommendations

In Europe, National Immunisation Technical Advisory Groups (NITAGs) were established in most countries to promote evidence-informed decision-making in introducing new or improved vaccines or changing recommendations for existing ones. Still, the role, activities and outcomes of NITAGs have not been optimally implemented across Europe. Within the European Joint Action on Vaccination (EU-JAV), we conducted a survey to collect information on decision-making process including the main criteria for the introduction of new vaccines or changes to recommendations on their use. Between December 2021 and January 2022, 13 of the 28 European countries invited participated in an online survey. The criteria ranked as most relevant were disease burden and availability of financial resources. Only one country specified that the NITAG recommendations were binding for the government or the health authority. Vaccinations more often reported for introduction or recommendation changes were those against herpes zoster, influenza, human papillomavirus infection, pneumococcal and meningococcal disease. The planned changes will mainly address children and adolescents (2-18 years) and adults (≥ 45-65 years). Our findings show potential overlaps in the activities of NITAGs between countries; and therefore, collaboration between NITAGs may lead to optimisation of the workload and better use of resources.

Prevalence and management of rubella susceptibility in healthcare workers in Italy: A systematic review and meta-analysis

Introduction

In the pre-vaccination era, all adults acquired immunity status due to natural infections during childhood and adolescence, whereas universal mass vaccination has changed the seroepidemiology of rubella among adults, showing lack of immunity in some subgroups. National and international guidelines recommend evaluating all healthcare workers (HCWs) for their immune status to rubella and possibly vaccinating those who are seronegative. We conducted a systematic review and meta-analysis to estimate the susceptibility rate to rubella among HCWs in Italy and to explore possible options for the management of those found to be susceptible.

Methods

Eight studies were included in the meta-analysis, selected from scientific papers available in the MEDLINE/PubMed and Google Scholar (till page 10) databases between January 1, 2015 and November 30, 2021. The following terms were used for the search strategy: (sero* OR seroprevalence OR prevalence OR susceptibilit* OR immunit* OR immunogenict*) AND (healthcare worker* OR health personnel OR physician* OR nurse OR student*) AND (rubella OR german measles OR TORCH) AND (Italy)

Results

The prevalence of rubella-susceptible HCWs was 9.0 % (95 %CI: 6.4–12.1 %). In a comparison of female vs. male serosusceptible HCWs, the RR was 0.67 (95 %CI = 0.51–0.88). Occupational medicine examinations for rubella screening with possible subsequent vaccination of seronegatives and exclusion of susceptible HCWs from high-risk settings were common management strategies.

Conclusions

HCWs susceptible to rubella are an important epidemiological concern in Italy, and efforts to identify and actively offer the vaccine to this population should be increased.

Sex and age as determinants of the seroprevalence of anti-measles IgG among European healthcare workers: A systematic review and meta-analysis

INTRODUCTION

The international literature shows good evidence of a significant rate of measles susceptibility among healthcare workers (HCWs). As such, they are an important public health issue.

METHODS

We conducted a systematic review and meta-analysis to estimate the prevalence of susceptible HCWs in EU/EEA countries and in the UK and to explore the characteristics (sex and age differences) and management of those found to be susceptible.

RESULTS

Nineteen studies were included in the meta-analysis. The prevalence of measles-susceptible HCWs was 13.3% (95 %CI: 10.0-17.0%). In a comparison of serosusceptible female vs. male HCWs, the RR was 0.92 (95 %CI = 0.83-1.03), and in a comparison of age classes (born after vs. before 1980) the RR was 2.78 (95 %CI = 2.20-3.50). The most recent studies proposed the mandatory vaccination of HCWs.

DISCUSSION

According to our meta-analysis, the prevalence of serosusceptible European HCWs is 13%; HCWs born in the post-vaccination era seem to be at higher risk. Healthcare professionals susceptible to measles are a serious epidemiological concern. Greater efforts should therefore be made to identify those who have yet to be vaccinated and actively encourage their vaccination.

Nudging influenza vaccination among health care workers

Our online randomized controlled trial on 6230 healthcare workers (HCWs) tests the impact that three nudges - social norms, reminding the impact on beneficiaries, and defaults - have on the intention to vaccinate against seasonal influenza across job families. Willingness to get a flu shot was higher among subjects invited to imagine themselves working at the local health authority (LHA) with the greatest immunization coverage within their region relative to their counterparts prompted to imagine working at the LHA with the lowest coverage. Reminding the impact of flu vaccination on beneficiaries had different effects across job families, with physicians caring more benefits for themselves, nurses about patients' benefits, and technicians about family and friends. Default responses anchoring toward a high rather than a low vaccination intention increased the willingness to immunize among all HCW except physicians. Targeted nudges can be considered in developing interventions to promote influenza vaccination among HCWs.

Vaccination Status of Mothers and Children from the 'Mamma & Bambino' Cohort

According to the evidence demonstrating vaccines’ safety and effectiveness in anticipation of and during pregnancy, several countries have established immunization programs during the periconceptional period. Here, we evaluated vaccination status among 220 mother–child pairs, using data from the ‘Mamma & Bambino’ cohort. The self-reported data were evaluated at delivery, and with planned follow-ups at 1–2 years after delivery. In general, we noted that the vaccination status among the women was heterogeneous, ranging from 8.3% (vaccine against Human Papillomavirus, HPV) to 65.6% (vaccine against Diphtheria Tetanus and Pertussis, DTaP). Excluding the women who contracted the diseases in the past, the main ground for refusal was the lack of information. We also demonstrated that increasing age was associated with higher odds of not being vaccinated against Measles-Mumps-Rubella (MMR; OR = 1.12; 95% CI = 1.04–1.21; p = 0.004), HPV (OR = 1.20; 95% CI = 1.08–1.33; p = 0.001) and DTaP (OR =1.09; 95% CI = 1.01–1.18; p = 0.040). As expected, we showed that the proportion of newborns vaccinated with the Hexavalent and Pneumococcal vaccines was high (99.5% and 98.6%, respectively), while the vaccination coverage against MMRV did not reach the auspicated threshold (84.1%). Overall, these results underlined the need for the improvement of women’s knowledge about the recommendations for vaccination, especially during pregnancy.

A Wide Range of Strategies to Cope with Healthcare Workers' Vaccine Hesitancy in A North-Eastern Italian Region: Are They Enough?

The recent pandemic reminded the world of the high risk of healthcare workers (HCWs) and patient contagiousness along with the healthcare services disruption related to nosocomial outbreaks. This study aims at describing vaccination campaigns within healthcare institutions of a North-Italian Region and comparing their effectiveness in term of vaccination coverage. In December 2019, we surveyed all healthcare institutions of Friuli Venezia Giulia Region throughout an email questionnaire with 15 questions investigating strategies adopted for the vaccination of HCWs against influenza and other vaccine-preventable diseases (VPDs), along with actions put in place in case of a VPD exposure. We found a strong heterogeneity in VPDs prevention and control policy and practice for HCWs, along with responsibility attribution ranging among different stakeholders. Strategies adopted to promote vaccination included a wide range of methods, but HCWs' influenza vaccination coverage still ranged from 17.0 to 33.3%. Contact tracing after a VPD exposure did not always include medical residents and students and visitors/caregivers/extra personnel as possible contacts. Even if knowledge and complacency gaps among HCWs could be faced with education activities, more efforts should be done in identifying and implementing effective vaccination strategies, and mandatory vaccination for HCWs could be introduced to achieve host, herd, and healthcare immunity preventing possible hospital outbreaks.

Adherence to Vaccination Policy among Public Health Professionals: Results of a National Survey in Italy

Starting from 2013, the number of unvaccinated people alarmingly increased in Italy; therefore, in 2017 a new Vaccine National Plan was approved. Healthcare workers (HCWs), especially public health professionals (PHPs, i.e., workers in in the sector of hygiene and preventive medicine), have an important role in informing and promoting vaccinations. In this context, the Italian Study Group of Hospital Hygiene of the Italian Society of Hygiene, Preventive Medicine and Public Health (GISIO-SItI) conducted a national survey to assess knowledge, attitude, and practices towards recommended vaccinations among PHPs. The survey was conducted during October 2019 with an anonymous questionnaire distributed to PHPs attending the 52° SItI National Congress. Overall, 57.1% of operators answered correctly to all seven recommended vaccinations, 12.8% reported to be vaccinated for all seven recommended vaccinations, while 30% were naturally immunized. A higher immunization coverage was reported for anti-hepatitis B (88.9%) and measles (86.1%), and 81.3% of the participants reported being offered the influenza vaccination during the 2018/2019 season. The majority of our sample indicated that hepatitis B (95%) and influenza (93.7%) were the recommended vaccines for HCWs, while less was known regarding varicella, pertussis, diphtheria, and tetanus boosters every 10 years. PHPs who were vaccinated (or who intended to be vaccinated) were more likely to recommend vaccinations to their patients and provided a reassuring example to those hesitant patients. Finally, this is the first study that identified good algorithms (using the techniques of machine learning as Random Forest and Deep Learning) to predict the knowledge of PHPs regarding recommended vaccinations with possible applications in other national and international contexts.