Measles outbreaks in Italy: A paradigm of the re-emergence of vaccine-preventable diseases in developed countries

Public health impact and return on investment of the pediatric national immunization program in Italy

OBJECTIVES

We conducted a cost-benefit analysis of the pediatric National Immunization Program (NIP) in Italy.

METHODS

An economic model evaluated the benefit-cost ratio (BCR) of the Italian pediatric NIP, including 10 pathogens for mandatory vaccines and 4 pathogens for recommended vaccines for children aged 0-10 years from the healthcare-sector and societal perspectives. Separate decision trees were used to model each vaccine-preventable disease (VPD). The 2020 birth cohort (n = 420,084) was followed over their lifetime; the model projected and compared discounted disease cases, life-years, quality-adjusted life-years (QALYs), and costs (2021 euros) with and without immunization (based on current and pre - vaccine era disease incidence estimates, respectively).

RESULTS

The pediatric NIP was estimated to prevent 1.8 million cases of VPDs and 3,330 deaths, resulting in 45,900 fewer life-years lost and 57,000 fewer QALYs lost. Vaccination costs of €285 million were offset by disease cost savings of €1.6 billion, resulting in a BCR of 5.6 from a societal perspective (BCR = 1.7 from a healthcare-sector perspective). When QALYs gained were valued, the BCR increased to 15.6.

CONCLUSIONS

The benefits of the Italian pediatric NIP, including averted disease-related morbidity, mortality, and associated costs, highlight the value of continued investment in pediatric immunization.

Enhancing vaccination strategies for epidemic control through effective lockdown measures

Evolutionary epidemiology models have substantially impacted the study of various infections and prevention methods in the biology field. These models are called Susceptible, Lockdown, Vaccinated, Infected, and Recovered (SLVIR) epidemic dynamics. We explore how human behavior, particularly in the context of disease transmission, is influenced by two intervention strategies: vaccination and lockdown, both of which are grounded in the principles of evolutionary game theory (EGT). This comprehensive study using evolutionary game theory delves into the dynamics of epidemics, explicitly focusing on the transition rate from susceptibility to immunity and susceptibility to lockdown measures. Our research involves a thorough analysis of the structural aspects of the SLVIR epidemic model, which delineates disease-free equilibria to ensure stability in the system. Our investigation supports the notion that implementing lockdown measures effectively reduces the required level of vaccinations to curtail the prevalence of new infections. Furthermore, it highlights that combining both strategies is particularly potent when an epidemic spreads rapidly. In regions where the disease spreads comparatively more, our research demonstrates that lockdown measures are more effective in reducing the spread of the disease than relying solely on vaccines. Through significant numerical simulations, our research illustrates that integrating lockdown measures and efficient vaccination strategies can indirectly lower the risk of infection within the population, provided they are both dependable and affordable. The outcomes reveal a nuanced and beneficial scenario where we examine the interplay between the evolution of vaccination strategies and lockdown measures, assessing their coexistence through indicators of average social payoff.

Steroid use in measles: A retrospective cohort study during the 2017 outbreak in tertiary referral center, Rome and Latina, Italy

INTRODUCTION

Since early January 2017, a new measles outbreak in Italy has been observed. The aim of the study was to compare features between adults and children measles cases and evaluate the effect of steroid treatment on the above parameters.

METHODS

A retrospective multicenter, descriptive study was performed. We analyzed all patients admitted to the Department of Public Health and Infectious Diseases, Sapienza University, Rome and Latina, from January 2017 to December 2017 and discharged with diagnosis of measles.

RESULTS

We identified 113 patients discharged with the diagnosis of measles infection cases of which 59 adults and 54 children (≤16 years). In adult population 32 patients (54 %) were males, with a median age of 30.5 years old and all unvaccinated (100 %). Keratoconjunctivitis 30 (50 %) was the most frequent complication. In pediatric population 27 (50 %) patients were males, with a median age of 3 years old. Information on measles vaccination status was available for only 21 (38.8 %) of cases. Keratoconjunctivitis 40 (74 %) was the most frequent complication. Analyzing the differences between adult and pediatric patients we found that children were significantly more likely to have keratoconjunctivitis and diarrhea as complications than adults in which the rate of thrombocytopenia and hepatitis was highest. Thirty-nine adult subjects (66 %) have been treated with systemic corticosteroids.

CONCLUSIONS

Pediatric patients differ from adults in complications and liver involvement. Regarding steroids use, although there is no clear indication of steroid use during measles, there is no evidence of a worse outcome in our cases series.

Worldwide Child Routine Vaccination Hesitancy Rate among Parents of Children Aged 0-6 Years: A Systematic Review and Meta-Analysis of Cross-Sectional Studies

Routine vaccine hesitancy is a major global health challenge observed in over 190 countries worldwide. This meta-analysis aims to determine the worldwide prevalence of routine vaccination hesitancy among parents of children aged 0-6. An extensive search was conducted in four scientific databases: PubMed, Scopus, Web of Science, and the Cochrane Library. Studies were included if they reported hesitancy related to WHO-recommended routine immunizations for children under 7 years of age. A single-arm meta-analysis was performed using the OpenMeta[Analyst] software. An initial search retrieved 5121 articles, of which only 23 publications, involving 29,131 parents, guardians, and caregivers from over 30 countries met the inclusion criteria and quality assessment. The cumulative prevalence of parental vaccine hesitancy was found to be 21.1% (95% CI = 17.5-24.7%, I2 = 98.86%, p < 0.001). When stratifying the prevalence of vaccine hesitancy per WHO region, significant variations were observed, ranging from 13.3% (95% CI = 6.7-19.9%, I2 = 97.72%, p < 0.001) in the Region of the Americas to 27.9% (95% CI = 24.3-31.4%) in the Eastern Mediterranean region. The study findings highlight the need for healthcare providers and governments to develop and improve comprehensive programs with communication strategies to reduce parental vaccine hesitancy.

Vaccine Hesitancy in Central Switzerland: Identifying and Characterizing Undervaccinated Children in a Pediatric Emergency Department

Vaccinations play an important role in the prevention of potentially fatal diseases. Vaccine hesitancy has become an important problem both in the public discourse and for public health. We aimed to identify and characterize this potentially unvaccinated or incompletely vaccinated group of children presenting to the pediatric emergency department (PED) of the tertiary children's hospital in central Switzerland, a region that has anecdotally been claimed as a hotspot for vaccine hesitancy. All patients presenting to the PED (N = 20,247) between September 2018 and September 2019 were screened for their vaccination status and categorized as incomplete, unvaccinated, or fully vaccinated in a retrospective cohort study. Some 2.6% (n = 526) visits to the PED were not or incompletely vaccinated according to age, or their vaccination status was unknown. Most of the children in the cohort were not critically ill, and the minority had to be hospitalized. Undervaccinated patients were overrepresented in rural areas. Of all cohort visits, 18 (3.4%) patients received opportunistic vaccination in the PED. No cases of vaccine-preventable diseases were observed. In summary, incompletely vaccinated and unvaccinated status was less frequent than initially expected. The PED may play a role in increasing vaccination coverage by providing opportunistic vaccinations.

Understanding Factors Contributing to Vaccine Hesitancy in a Large Metropolitan Area

Vaccine hesitancy has become a major global concern, leading to a significant decrease in the vaccination rate, with the World Health Organization recognizing it as one of the top ten threats to public health. Moreover, the health cost generated is evaluated to be 27 billion dollars per year in the US alone. To investigate the association between demographic variables and knowledge, attitudes, and behaviours related to vaccination, a survey-based cross-sectional study was conducted with 1163 individuals. Three models were used to perform a multiple linear regression analysis. In Model I, knowledge about vaccinations was found to be associated with smoking habits, education, and marital status. In Model II, attitudes towards vaccinations were significantly associated with sex, smoking habits, education, marital status, and knowledge. In Model III, behaviours related to vaccination were associated with sex, smoking habits, having children, knowledge, and attitudes. One potential solution to improve behaviours related to vaccinations in the general population is to implement specific public health programs, which can be a cost-effective intervention. This study provides valuable insights into the determinants of knowledge, attitudes, and behaviours related to vaccinations in the general population.

Review of Vaccination Recommendations in Guidelines for Non-Communicable Diseases with Highest Global Disease Burden among Adults 75 Years Old and Above

This scientific review paper explores international and country-specific healthcare guidelines for non-communicable diseases with the highest burden among individuals aged 75 years and above. The study aims to identify the best vaccination practices and standardize healthcare practices to improve vaccination adherence in this vulnerable population. Given that older people are more prone to infectious illnesses and have higher rates of morbidity and mortality, vaccinations are essential for disease prevention. Despite the proven efficacy of vaccinations, adherence has plateaued in recent years, partly due to a lack of accessibility, public education, and variability in disease-specific guidelines. This paper highlights the need for a more robust and standardized international vaccination model to improve quality of life and reduce disability-adjusted life years among the elderly. The findings of this study call for further research to review the guidelines as more implementations are put in place, including non-English guidelines.

Influence of Acute and Chronic Graft-Versus-Host Disease on Persistence of Antibodies against Measles, Mumps, Rubella and Varicella in the First Year after Autologous or Allogeneic Hematopoietic Stem Cell Transplantation

Patients after hematopoietic stem cell transplantation (HSCT) are vulnerable to infections due to severe immunosuppression. Live-attenuated vaccines are contraindicated for two years after HSCT. The aim of this study was to assess the persistence of antibodies against measles, mumps, rubella and varicella in the first year after HSCT. Forty patients undergoing autologous (n = 12) or allogeneic (n = 28) HSCT were included in this study. Specific IgG antibodies to measles, mumps, rubella and varicella virus in serum samples were assessed by the LIAISON XL, a fully automated chemiluminescence analyzer, at seven different time points starting one week before HSCT and up to 12 months after HSCT. At baseline, before HSCT, most patients showed antibodies against measles (100%), mumps (80%), rubella (97.5%) and varicella (92.5%). Although titers declined over time, most patients retained antibodies against measles (92.5%), mumps (62.5%), rubella (87.5%) and varicella (85%) up to 12 months after HSCT. There was no significant difference between patients with and without GvHD concerning persistence of antibody titers. Significantly higher varicella titers were detected in autologous patients compared to patients with chronic GvHD. Considering that live-attenuated vaccines should not be administered during the first year after HSCT, the persistence of antibodies against these diseases is relevant.

Effect of vaccination patterns and vaccination rates on the spread and mortality of the COVID-19 pandemic

Objectives

Acquiring herd immunity through vaccination is the best way to curb the COVID-19 infection. Many countries have attempted to reach the herd immunity threshold as early as possible since the commencement of vaccination at the end of 2020. The purpose of this study is to (1) examine whether the pattern of vaccination rates affects the spread of COVID-19 and the consequent mortality and (2) investigate the level of cumulative vaccination rates that can begin to have an impact on reducing the spread and mortality of the pandemic.

Methods

This study selected 33 countries with higher vaccination rates as its sample set, classifying them into three groups as per vaccination patterns.

Results

The results showed that vaccination patterns have a significant impact on reducing spread and mortality. The full-speed vaccination pattern showed greater improvement in the spread of the COVID-19 pandemic than the other two patterns, while the striving vaccination pattern improved the most in terms of mortality. Secondly, the spread and mortality of the COVID pandemic started to significantly decline when the average cumulative vaccination rate reached 29.06 doses per 100 people and 7.88 doses per 100 people, respectively.

Conclusion

The study highlights the important role of vaccination patterns and the VTMR in reducing the epidemic spread and mortality.

Is vaccine confidence an unexpected victim of the COVID-19 pandemic?

Vaccines are among the safest and most effective primary prevention measures. Thanks to the synergistic global efforts of research institutions, pharmaceutical companies and national health services, COVID-19 vaccination campaigns were successfully rolled out less than a year after the start of the pandemic. While the unprecedented speed of development and approval of COVID-19 vaccines has been applauded as a public health success story, it also spurred considerable controversy and hesitancy even amongst individuals that did not previously hold anti-vaccination stances. This study aimed to compare pre- and post-pandemic vaccine confidence trends in different demographic groups by analysing the outcomes of two online surveys run respectively in November 2019 and January 2022 involving a total of 1009 participants. Non-parametric tests highlighted a statistically significant decline in vaccine confidence in the 2022 cohort compared to the 2019 cohort, with median Vaccine Confidence Score dropping from 22 to 20 and 23.8% of participants reporting that their confidence in vaccines had declined since the onset of the pandemic. While the majority of internal trends were comparable between the two surveys with regards to gender, graduate status and religious belief, vaccine confidence patterns showed considerable alterations with regards to age and ethnicity. Middle-aged participants were considerably more hesitant than younger groups in the 2019 cohort, however this was not the case in the 2022 survey. In both surveys White participants showed significantly higher vaccine confidence than those from Black backgrounds; in the 2022 cohort, unlike the pre-pandemic group, Asian participants showed significantly lower confidence than White ones. This study suggests that paradoxically, despite the success of COVID-19 vaccination campaigns, vaccine confidence has significantly declined since the onset of the pandemic; the comparison of a pre- and post-pandemic cohort sheds light on the differential effect that the pandemic had on vaccine confidence in different demographic groups.

Black-and-white thinking and conspiracy beliefs prevent parents from vaccinating their children against COVID-19

Understanding predictors of parents' willingness to vaccinate their children appears fundamental to promote vaccine acceptability, especially in a pandemic scenario. The present study aimed to investigate the role of conspiracy beliefs and absolutist thinking in parental attitude toward COVID-19 vaccine, and the predictive role of parents' individual differences on decisions against children's vaccination. An online survey was administered to 415 parents of children aged 5-11, at the very beginning of the vaccination targeting this population in Italy. Results showed that absolutism predicted the tendency to believe in conspiracies, associated with a negative attitude toward the COVID-19 vaccine administration to children. Moreover, mothers were less willing to vaccinate children and parents of children aged 5-7 were more hesitant, or even against vaccination, than parents of older children. Finally, the worry about consequences of COVID-19 infection on children's health facilitated vaccine adherence. These findings contribute to deepening mechanisms regarding the vaccine acceptability.

Vaccination Status and Attitudes towards Vaccines in a Cohort of Patients with Celiac Disease

(1) Background: The identification of vaccination status and attitudes towards vaccines among celiac disease (CD) patients is of great importance, but it has not yet been investigated. The aim of this study was to investigate coverage against vaccine-preventable diseases (VPDs), attitudes towards vaccinations, and its determinants among CD patients. (2) Methods: An anonymous web-based validated questionnaire was sent to a mailing list of CD adult patients. Patients were asked to self-report their previous vaccinations and attitudes towards vaccinations, which were defined as positive, negative, and partially positive/negative. The influencing factors towards vaccinations were investigated, and crude and adjusted odds ratios (AdjORs) with 95% confidence intervals (CIs) were calculated. (3) Results: The questionnaire was sent to 412 patients, with a response rate of 31.6% (130 patients, 105 women, median age 40 years, interquartile range 36–51). Patients self-reported vaccination against the following diseases: 73.8% tetanus, 42.3% flu, 20% measles, mumps and rubella, 19.2% meningitis, and 16.2% pneumococcus. Thirty-two people (24.6%) did not remember all of their previous vaccinations. In total, 104 (80%) respondents had a positive attitude towards vaccines, 25 (19.2%) a partially positive/negative one, and 1 a negative one. The determinants significantly influencing the positive attitude were being a graduate (AdjORs 7.49) and a belief in the possible return of VPDs with declining vaccination coverage rates (AdjORs 7.42), while the use of complementary and alternative medicines (AdjORs 0.11) and past negative experience (AdjORs 0.16) were associated with a negative attitude. (4) Conclusions: Despite four out of five CD patients showing a strong positive attitude towards vaccinations, one out of five had a partially negative one. Only a minority (16–20%) reported being vaccinated against some VPDs potentially harmful to their CD because of hyposplenism, such as meningitis and pneumococcus. The low vaccination rate against some VPDs, in spite of the 80% of CD patients stating a positive attitude towards vaccination, may be explained in part by patients’ vaccine hesitancy and in part by a possible role of physicians in under-prescribing vaccinations to these patients. These results may be a starting point for developing specific vaccination campaigns to increase vaccination rates against VPDs in CD patients.

Identifying immunity gaps for measles using Belgian serial serology data

Vaccine-preventable diseases, such as measles, have been re-emerging in countries with moderate to high vaccine uptake. It is increasingly important to identify and close immunity gaps and increase coverage of routine childhood vaccinations, including two doses of the measles-mumps-rubella vaccine (MMR). Here, we present a simple cohort model relying on a Bayesian approach to evaluate the evolution of measles seroprevalence in Belgium using the three most recent cross-sectional serological survey data collections (2002, 2006 and 2013) and information regarding vaccine properties. We find measles seroprevalence profiles to be similar for the different regions in Belgium. These profiles exhibit a drop in seroprevalence in birth cohorts that were offered vaccination at suboptimal coverages in the first years after routine vaccination has been started up. This immunity gap is observed across all cross-sectional survey years, although it is more pronounced in survey year 2013. At present, the COVID-19 pandemic could negatively impact the immunization coverage worldwide, thereby increasing the need for additional immunization programs in groups of children that are impacted by this. Therefore, it is now even more important to identify existing immunity gaps and to sustain and reach vaccine-derived measles immunity goals.

Perceptions of the safety of vaccines and vaccine associated knowledge levels in Europe: A 2019 cross-sectional study in 28 countries

Vaccination has saved millions of lives. Vaccine hesitancy was recently declared a major threat to health by the World Health Organisation. Sociodemographic variables and knowledge level about vaccines have been suggested previously to affect vaccine uptake. This study aimed to investigate how levels of vaccination knowledge and concerns around safety of vaccines varied across sociodemographic factors in the European Union and United Kingdom. Levels and sources of knowledge and vaccine attitude patterns were examined across different areas of Europe. Data from the March 2019 Eurobarometer survey was used in this study which had 27,524 participants across the European Union and the United Kingdom. Two-level logistic and linear regressions were used to look for associations between sociodemographic variables, vaccine attitudes and knowledge level. Those who trusted information from healthcare workers and healthcare authorities were most likely to have positive vaccine attitudes; those trusting internet sources the most were the least likely. Those with greater vaccine related knowledge were more likely to report positive vaccination attitudes. Healthcare workers are key to dissemination of vaccination advice however many are becoming hesitant themselves. An increasing number of people are seeking online sources for vaccination information, and this has implications with information accuracy and vaccine hesitancy. A considerable proportion of the adult population in the European Union and the United Kingdom was concerned about the safety or side effects of vaccines. Continued efforts to increase trust in vaccines both in whole populations and specific groups are needed.

The Determinants of Vaccine Literacy in the Italian Population: Results from the Health Literacy Survey 2019

Vaccines are among the most important public health achievements of the last century; however, vaccine awareness and uptake still face significant challenges and the COVID-19 pandemic has only exacerbated this phenomenon. Vaccine Literacy (VL) is the ability to find, understand and judge immunisation-related information to make appropriate immunisation decisions. A cross-sectional study on a sample of 3500 participants, representative of the Italian adult population aged 18+ years, was conducted in Italy in 2021. A validated questionnaire, including sections on health literacy (HL), sociodemographic characteristics, risk factors, and lifestyles of respondents, was used. VL was measured by four items (item 19, 22, 26 and 29) of the HL section. While 67.6% of the respondents had a “good” (47.5%) or “sufficient” (20.1%) level of VL, 32.4% had “limited” VL levels. Although the overall VL level was quite high, many participants reported difficulties in dealing with vaccination information, particularly those with a lower educational level, those living in southern and insular regions of Italy, those with greater financial deprivation and those with a migration background. Improving VL in Italy should be a top priority in the political agenda, with special regard to socially and geographically disadvantaged communities.

Evolving measles status and immunization policy development in six European countries

Developing and implementing new immunization policies in response to shifting epidemiology is a critical public health component. We adopted a mixed-methods approach (via narrative literature review [101 articles] and 9 semi-structured interviews) to evaluate policy development in response to shifting measles epidemiology in six European countries (Italy, Belgium, Germany, Romania, UK, and Ukraine); where policies and strategies have evolved in response to country-specific disease and vaccination patterns. Periodic outbreaks have occurred in all countries against a background of declining measles-containing-vaccine (MCV) uptake and increasing public vaccine hesitancy (with substantial regional or social differences in measles burden and vaccine uptake). Health-care worker (HCW) vaccine skepticism is also seen. While many outbreaks arise or involve specific susceptible populations (e.g., minority/migrant communities), the broader pattern is spread to the wider (and generally older) population; often among incompletely/non-vaccinated individuals as a legacy of previous low uptake. Immunization policy and strategic responses are influenced by political and social factors, where public mistrust contributes to vaccine hesitancy. A strong centralized immunization framework (allied with effective regional implementation and coherent political commitment) can effectively increase uptake. Mandatory vaccination has increased childhood MCV uptake in Italy, and similar benefits could be anticipated for other countries considering vaccine mandates. Although possible elsewhere, socio-political considerations render mandating impractical in other countries, where targeted immunization activities to bolster routine uptake are more important. Addressing HCW skepticism, knowledge gaps, improving access and increasing public/community engagement and education to address vaccine hesitancy/mistrust (especially in communities with specific unmet needs) is critical.

Vaccine hesitancy in Western and Eastern Europe: The significance of contextual influences

Using the example of Eastern and Western Europe, the paper points out the importance of contextual influences on decisions and behaviour regarding vaccines and vaccination. Contextual determinants have been identified as important in theorizing the concept of vaccine hesitancy that allows for a comprehensive understanding of the reasons why the public questions vaccines. Therefore, the paper first presents the theoretical elaboration of the aforementioned concept, and then discusses the contextual influences on vaccine hesitancy within the European region in order to showcase the differences that exist in this respect between Western and Eastern Europe, as well as between certain minority communities and the majority population in some Western European countries. In all cases, vaccine hesitancy appears to be a matter of trust which has been further eroded by social, political and economic experiences characteristic for the post-socialist context in Eastern Europe and the conditions in which some minority communities live in Western Europe. The theoretical framework of the concept of vaccine hesitancy is presented according to the report of the SAGE Working Group on Vaccine Hesitancy, while the presentation of contextual determinants is based on the results of quantitative and qualitative research in different European countries and reviews of studies that focus on these influences.

Survey among Italian experts on existing vaccines' role in limiting antibiotic resistance

Antimicrobial resistance (AMR) is a major public health problem threatening to reverse the progress made against infectious diseases. The rapid increase of AMR exposes Italian hospitals at increased risk of untreatable infections. Vaccinations can potentially limit AMR by reducing the number of infected cases in need of antibiotics. We conducted a survey among Italian vaccine experts to record their opinion regarding the role of vaccinations against antibiotic resistance (ABR). Among 80 invited experts, 51 answered all questions. Most respondents were experts in hygiene and preventive medicine (56.9%) and aged >50 years (72.6%). ABR was a priority concern in the daily professional activity of 82.4% of respondents. Overall, 47.1% of respondents believed that all vaccinations included in the vaccination calendar played a role against ABR: 92.2% for pertussis vaccination followed by 88.2%, 74.5%, and 70.6% for meningococcus, measles, and varicella vaccinations, respectively. Almost all respondents agreed that the role of vaccinations against ABR should be clearly expressed in the national vaccination guidelines (96.1%) and Scientific Societies should take an explicit position on the issue (92.2%). These results show that Italian experts have recognized the vaccinations' potential role in limiting ABR and guidelines from the appropriate scientific and governmental authorities are needed.

Correlation between measles immunization coverage and overall morbidity and mortality for COVID-19: an epidemiological study

We conducted the current analysis to determine the potential role of measles vaccination in the context of the spread of COVID-19. Data were extracted from the World Health Organization's (WHO) Global Health Observatory data repository about the measles immunization coverage estimates and correlated to overall morbidity and mortality for COVID-19 among different countries. Data were statistically analyzed to calculate the Spearman rank correlation coefficient (rho). There was a significant positive correlation between the vaccine coverage (%) and new cases per one million populations (rho = 0.24; p-value = 0.025); however, this correlation was absent in deaths per one million populations (rho = 0.17; p-value = 0.124). On further analysis of the effect of first reported year of vaccination policy, there was no significant correlation with both of total cases per one million populations (rho = 0.11; p-value = 0.327) and deaths per one million populations (rho = -0.02; p-value = 0.829). Claims regarding the possible protective effect of measles vaccination seem to be doubtful.

Vaccine Hesitancy and Trust in the Scientific Community in Italy: Comparative Analysis from Two Recent Surveys

Vaccination rates in Italy fell until 2015 because of unfounded safety concerns. Public education and a 2017 law on mandatory vaccination have boosted rates since then. The aim of our study is to explore how trust in the scientific community and attitudes towards vaccines have changed in the period of 2017-2019 in Italy. Data were extracted from the Italian section of the 2017 and 2019 editions of the European Social Survey (ESS). We compared the two surveys highlighting changes in public opinion on vaccines. A descriptive analysis of the socio-cultural variables according to the answers provided to key questions on the harmfulness of vaccines was conducted. Differences between percentages were tested by using the χ2 test. The association between the opinion about the harmfulness of vaccines and trust in the scientific community was analyzed through a logistic regression model. Compared to ESS8, ESS9 showed an increase in the percentage of respondents disagreeing with the harmfulness of vaccines. Trust in the scientific community raised in the period from 2017 to 2019 (59% vs. 69.6%). Higher education was significantly associated with disagreement regarding the harmfulness of vaccines (odds ratio (OR) = 2.41; 95% confidence interval (95%CI) 1.75-3.31), the strongest predictor was trust in the scientific community (OR = 10.47; 95% CI 7.55-14.52). In Italy, trust in the scientific community and in vaccinations has grown significantly in recent years, indicating a paradigm shift in public opinion compared to the past. Central actions and effective public communication strategies might reduce vaccine hesitancy and could be essential to garner public trust.

Evidence of disorientation towards immunization on online social media after contrasting political communication on vaccines. Results from an analysis of Twitter data in Italy

Background

In Italy, in recent years, vaccination coverage for key immunizations as MMR has been declining to worryingly low levels, with large measles outbreaks. As a response in 2017, the Italian government expanded the number of mandatory immunizations introducing penalties to unvaccinated children’s families. During the 2018 general elections campaign, immunization policy entered the political debate with the government in-charge blaming oppositions for fuelling vaccine scepticism. A new government (formerly in the opposition) established in 2018 temporarily relaxed penalties and announced the introduction of forms of flexibility.

Objectives and methods

First, we supplied a definition of disorientation, as the “lack of well-established and resilient opinions among individuals, therefore causing them to change their positions as a consequence of sufficient external perturbations”. Second, procedures for testing for the presence of both short and longer-term collective disorientation in Twitter signals were proposed. Third, a sentiment analysis on tweets posted in Italian during 2018 on immunization topics, and related polarity evaluations, were used to investigate whether the contrasting announcements at the highest political level might have originated disorientation amongst the Italian public.

Results

Vaccine-relevant tweeters’ interactions peaked in response to main political events. Out of retained tweets, 70.0% resulted favourable to vaccination, 16.4% unfavourable, and 13.6% undecided, respectively. The smoothed time series of polarity proportions exhibit frequent large changes in the favourable proportion, superimposed to a clear up-and-down trend synchronized with the switch between governments in Spring 2018, suggesting evidence of disorientation among the public.

Conclusions

The reported evidence of disorientation for opinions expressed in online social media shows that critical health topics, such as vaccination, should never be used to achieve political consensus. This is worsened by the lack of a strong Italian institutional presence on Twitter, calling for efforts to contrast misinformation and the ensuing spread of hesitancy. It remains to be seen how this disorientation will impact future parents’ vaccination decisions.

Current understandings of the impact of mandatory vaccination laws in Europe

Vaccinations are among the most successful preventive tools to protect collective health. In response to alarming vaccines preventable diseases (VPDs) outbreaks resurgence, decreased vaccination coverage and vaccine refusal, several European countries have recently revised their vaccination policies introducing or extending mandatory vaccinations. This review examines the health, political and ethical aspects of mandatory vaccination.The authors first clarify terms and definitions and propose a conceptual framework of mandatory policies. Second, they describe the current status of mandatory childhood immunization programmes in Europe, assessing selected mandatory laws. Third, as the authors conduct a systematic review of the literature (retrieving from Medline 17 relevant records between 2010 and 2020), they take an analytical approach to measure the impact of mandatory vaccination policies on both VPDs control and immunization coverage, but also on population attitudes toward vaccines. 40% of European countries currently have mandatory vaccination policies; however, policies vary widely and, although there is evidence of increased vaccine uptake, their impact on informed adherence to preventive behaviors is scant.Although mandatory vaccination policies might be needed to protect collective health in times of emergency, public health goals of VPD prevention and health promotion should primarily be pursued through health education and population empowerment.

Immune amnesia induced by measles and its effects on concurrent epidemics

It has been recently discovered that the measles virus can damage pre-existing immunological memory, destroying B lymphocytes and reducing the diversity of non-specific B cells of the infected host. In particular, this implies that previously acquired immunization from vaccination or direct exposition to other pathogens could be partially erased in a phenomenon named ‘immune amnesia’, whose effects can become particularly worrisome given the actual rise of anti-vaccination movements. Here, we present the first attempt to incorporate immune amnesia into standard models of epidemic spreading by proposing a simple model for the spreading of two concurrent pathogens causing measles and another generic disease. Different analyses confirm that immune amnesia can have important consequences for epidemic spreading, significantly altering the vaccination coverage required to reach herd immunity. We also uncover the existence of novel propagating and endemic phases induced by immune amnesia. Finally, we discuss the meaning and consequences of our results and their relation with, e.g. immunization strategies, together with the possibility that explosive types of transitions may emerge, making immune-amnesia effects particularly dramatic. This work opens the door to further developments and analyses of immune-amnesia effects, contributing also to the theory of interacting epidemics on complex networks.

How Public Health Professionals View Mandatory Vaccination in Italy-A Cross-Sectional Survey

In response to the decline in child vaccination coverage and the subsequent occurrence of large vaccine-preventable disease outbreaks, in 2017 Italy introduced a new law that made ten vaccines mandatory for children aged 0-16 years. The policy change initiated an ongoing debate among the general public, as well as in the political arena and the scientific community, over this major public health concern. Hence, we conducted a survey aimed at assessing Italian public health professionals' attitudes towards and opinions on mandatory vaccination. A validated online questionnaire was administered to 1350 members of the Italian Society of Hygiene, Preventive Medicine and Public Health. Among the 1044 responders (response rate 77%), a large majority were in favour of the Italian mandatory vaccination law (91%) and against its repeal (74%). Nevertheless, according to our sample, maintaining a high level of vaccination coverage without the need to mandate would be preferable, and thus efforts to promote vaccine confidence and proactive vaccine uptake are still needed.

What Prompts Doctors to Recommend COVID-19 Vaccines: Is It a Question of Positive Emotion?

Vaccines are among the most successful and cost-effective public health tools and have greatly contributed to eliminating or controlling several serious vaccine-treatable diseases over the past century. To curb the spread of COVID-19, efficacious vaccination is emerging as essential in mitigating the disease and preventing deaths. Health care workers (HCW) are one of the first groups to receive vaccinations, so it is important to consider their attitudes to COVID-19 vaccination to better address barriers to widespread vaccination acceptance. This study aimed to evaluate variables that are linked with the recommendation of vaccines and intention to take-up vaccination against COVID-19 among the HCWs, in the context of the current pandemic. The study was conducted during the first week of the vaccination campaign dedicated to Italian HCWs, beginning in December 2020, and it involved all doctors in a public hospital in Sicily. The following questionnaires were administered: (1) The perceived vaccine trust questionnaire, measuring the degree of trust in vaccines by healthcare professionals both in general and for the protection of healthcare professionals themselves and patients; (2) the positive and negative affect scale-state (PANAS), for assessing positive and negative emotions in relation to their work as “frontline care providers”; (3) The locus of control of behaviour (LCB) to measure the extent to which subjects perceive responsibility for their personal behaviour (internal vs. external); (4) recommendation vaccines item, referring to the intention to recommend vaccination. The findings suggest that socio-demographic control variables (age, gender, and seniority) showed little or no predictive power in vaccine recommendation, while vaccine confidence, positive emotions, and internal locus of control were excellent predictors of vaccine recommendations by doctors. Younger doctors, both in age and experience, are more confident in vaccines and recommend them more frequently. It is essential to improve institutional communication addressed to doctors to enhance their role as vaccination facilitators.

Measles outbreak investigation process in low- and middle-income countries: a systematic review of the methods and costs of contact tracing

Aim

The occurrence of measles outbreaks has increased, and previously measles-free countries are experiencing a resurgence, making measles elimination by 2020 unlikely. Therefore, outbreak prevention and rapid response strategies will need to be intensified. This systematic review therefore examines whether contact tracing (CT) as compared to no CT is an effective means of reducing measles spread during outbreaks in low- and middle-income countries (LMICs).

Subject and methods

A systematic review was conducted by searching six databases (CINAHL, Global Health, Medline, Cochrane Library, Web of Science and PubMed). The 17 included articles were appraised using the Critical Appraisal Skills Programme checklists and analysed using a narrative synthesis.

Results

CT is often used alongside mass communication strategies and hospital record checks. Interviewing measles cases to identify contacts, and considering everyone who has shared a space with a case as a contact are common CT methods. Also, CT can be done backwards and/or forwards with the measles case as the focal point of the investigation process. The cost per case of an outbreak response dominated by CT is high especially in terms of labour for the health sector and productivity losses for households. However, overall outbreak expenditure can be low if CT results in fewer and less severe measles cases and a short outbreak duration.

Conclusion

CT data as a standalone and comparative active surveillance approach in LMICs is scarce. If CT is initiated early, it can prevent large outbreaks, thereby reducing the economic burden of measles and drive LMICs towards measles elimination.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10389-021-01590-2.

Investigating the determinants of vaccine hesitancy within undergraduate students' social sphere

Aims

Vaccine hesitancy is widely recognised as one of the most serious threats to current global health. While the causes underlying vaccine hesitancy have been extensively described and several mitigation strategies trialled amongst current and prospective parents, there is a relative scarcity of research investigating its extent and causative factors amongst university students, a critical demographic due to its temporal proximity to the average child-rearing age. The present study sought to address this literature gap by elucidating the social and demographic factors that might underpin vaccine hesitancy in university students.

Subject and methods

An anonymous online survey was carried out to investigate the opinions and perspectives on the practice of vaccination within undergraduate students’ social sphere. The statistical significance of the differences observed between groups of participants was analysed using non-parametric tests of variance.

Results

Amongst the 739 volunteers who participated in the survey, vaccine confidence varied significantly (p < 0.001) with age, ethnicity and religion, and to a lesser (yet still statistically significant) extent (p < 0.05) with graduate status. No statistically significant differences were observed with regard to gender or number of children.

Conclusions

By shedding new light on the factors underpinning vaccine hesitancy within undergraduate students’ social network, the present study provides a stepping stone towards the development of targeted mitigation strategies.

Vaccine attitudes among young adults in Asia: a systematic review

Introduction: Young adults may be facing growing threats from vaccine-preventable diseases (VPDs). However, vaccination of young adults may not have drawn adequate attention. In Asia, adensely populated region with ahigh proportion of low-income countries, VPDs impose more of an economic and social burden than in western countries. However, knowledge about attitudes toward vaccines among young Asians is limited. This study aims to fill that gap by describing attitudes toward vaccines and how well they are accepted among young Asian adults through asystematic review of relevant Chinese and English publications.Methods: A three-stage searching strategy was adopted to identify eligible studies published during 2009-2019 according to the selection criteria, resulting in 68 articles being included.Results: The review finds that vaccination coverage among young Asians is generally lower than among their western peers, and there is a lack of relevant study in many Asian countries. Factors influencing young Asians' attitudes toward vaccines are categorized into contextual level, individual and social level, and vaccine-specific level.Conclusion: These suggest that there is a need to strengthen young adults' vaccination programs and to promote vaccine-related information and government.

Low Seroprevalence of Measles-Specific IgG in Children of Three Ethnic Groups from Mexico: Influence of Age, Sex, Malnutrition and Family Size

BACKGROUND

The reemergence of measles represents a public health problem. The aim of the study was to determine the seroprevalence of IgG antibodies against measles in children of three ethnic groups in southern Mexico and the nutritional status and demographic risk factors associated.

METHODS

A cross-sectional study in 416 school-age children, 207 belonging to the Tlapaneco ethnic group, 101 to the Mixteco group and 108 were considered Mestizo. Sociodemographic data were collected, an anthropometric evaluation of the children was performed and a fasting blood sample was obtained from each child for the measurement of measles IgG antibodies by Enzyme-Linked Immunosorbent Assay (ELISA).

RESULTS

From the total sample, 59% of the children were seropositive for IgG antibodies against measles; in contrast, 41% lacked IgG antibodies. Measles antibody seropositivity was higher in girls (64%). 90.5% of 6-year-old children had higher antibodies seroprevalence, compared to the children between 10 and 13 years old (45.5%). In the three ethnic groups, age was negatively correlated with the index standard ratio (ISR) of measles antibody levels and the families with ≥8 members showed less seropositivity. According to the antibodies levels, most of the positive cases remained around 1 Standard Deviation (SD) of the ISR values and no underweight children had antibody levels above 2 SD.

CONCLUSIONS

The Anti-Measles serological coverage is low in children of three ethnic groups from Southern Mexico and the age, sex, malnutrition and family size are associated factors. Therefore, it is important to strengthen immunization campaigns, principally in vulnerable groups.

Management of Coronavirus Disease 2019 (COVID-19) Pandemic: From Diagnosis to Treatment Strategies

Following the emergence of severe acute respiratory syndrome (SARS) in 2002 and the Middle East respiratory syndrome (MERS) in 2012, the world is now combating a third large-scale outbreak caused by a coronavirus, the coronavirus disease 2019 (COVID-19). After the rapid spread of SARS-coronavirus (CoV)-2 (the virus causing COVID-19) from its origin in China, the World Health Organization (WHO) declared a Public Health Emergency of International Concern (PHEIC) on January 30, 2020. From the beginning of the COVID-19 pandemic, a significant number of studies have been conducted to better understand the biology and pathogenesis of the novel coronavirus, and to aid in developing effective treatment regimens, therapeutics, and vaccines. This review focuses on the recent advancements in the rapidly evolving areas of clinical care and management of COVID-19. The emerging strategies for the diagnosis and treatment of this disease are explored, and the development of effective vaccines is reviewed.

Immunogenicity and persistence of trivalent measles, mumps, and rubella vaccines: a systematic review and meta-analysis

BACKGROUND

Despite the universal use of the two-dose trivalent measles-mumps-rubella (MMR) vaccine in the past two decades, outbreaks of these diseases still occur in countries with high vaccine uptake, giving rise to concerns about primary and secondary failure of MMR vaccine components. We aimed to provide seroconversion and waning rate estimates for the measles, mumps, and rubella components of MMR vaccines.

METHODS

In this systematic review and meta-analysis we searched PubMed (including MEDLINE), Web of Science, and Embase for randomised controlled trials, cohort studies, or longitudinal studies reporting the immunogenicity and persistence of MMR vaccines, published in English from database inception to Dec 31, 2019. Studies were included if they investigated vaccine-induced immunity in healthy individuals who received a trivalent MMR vaccine, including different dosages and timepoints of vaccine administration. Studies featuring coadministration of MMR with other vaccines, maternal immunity to the MMR vaccine, or non-trivalent formulations of the vaccine were excluded. Pooled seroconversion and waning rates were estimated by random-effects meta-analyses. This study is registered with PROSPERO, CRD42019116705.

FINDINGS

We identified 3615 unique studies, 62 (1·7%) of which were eligible for analysis. Estimated overall seroconversion rates were 96·0% (95% CI 94·5-97·4; I2=91·1%) for measles, 93·3% (91·1-95·2; I2=94·9%) for mumps when excluding the Rubini strain, 91·1% (87·4-94·1; I2=96·6%) for mumps when including the Rubini strain, and 98·3% (97·3-99·2; I2=93·0%) for rubella. Estimated overall annual waning rates were 0·009 (95% CI 0·005-0·016; I2=85·2%) for measles, 0·024 (0·016-0·039; I2=94·7%) for mumps, and 0·012 (0·010-0·014; I2=93·3%) for rubella.

INTERPRETATION

Our meta-analysis provides estimates of primary and secondary vaccine failure, which are essential to improve the accuracy of mathematical and statistical modelling to understand and predict the occurrence of future measles, mumps, and rubella outbreaks in countries with high vaccine uptake.

FUNDING

European Research Council.

Efficacy, safety, and formulation issues of the combined vaccines

Introduction: Controlling the preventable infectious diseases is the main goal of vaccination. Among the vaccines, combined vaccines are of great importance for their social, public health, and economic values. It is stated that the combined vaccines are as efficient and safe as the monovalent vaccines. However, a concern has raised about the efficacy and safety of the combined vaccines due to the outbreaks of vaccine-preventable diseases and occurrence of serious adverse events. Areas covered: A retrospective literature search was conducted in the Google Scholar and PubMed databases to evaluate the efficacy and safety of the combined vaccines from 1980 to 2020 using appropriate keywords. Expert opinion: Several studies have shown efficacy and safety issues related to the combined vaccines. Different factors contribute to the inefficacy and lack of safety in the vaccines including formulation problems, limited data in the pre-licensure studies and challenges related to imperfection of the post-licensure surveillance systems. For surmounting the mentioned obstacles, there is a need to provide new formulations of the vaccines, revise the vaccines҆ safety and efficacy acceptance standards in the pre-licensure studies, improvement of post-licensure surveillance systems, and education of healthcare staff.

Increasing Measles Seroprevalence in a Sample of Pediatric and Adolescent Population of Tuscany (Italy): A Vaccination Campaign Success

Background: Despite the National Plan for the Elimination of Measles and congenital Rubella (NPEMcR), in 2017, a measles outbreak occurred in Italy, due to sub-optimal vaccination coverage (<95%) for many years. Since that year, the anti-measles vaccination became compulsory in minors (0–16 years) for school attendance. The aim of our study was to assess the immunity/susceptibility against measles in a representative sample of pediatric and adolescent (1–18 years) residents of the province of Florence (Tuscany, Italy), and to compare these results with two previous surveys (2003 and 2005–2006). Methods: The enzyme-linked immunosorbent assay (ELISA) was applied for a qualitative measurement of anti-measles antibodies on 165 sera. The anamnestic and vaccination status was also collected. Results: No measles notification was reported. The overall seropositivity was 88.5%; mostly in the 5–9 years old subjects (97.9%). Among the 152 vaccinated, 92.1% were positive. The seropositivity persisted after many years since the last dose of vaccine and tended to be more long-lasting in those who had received two or three doses. The susceptibility towards measles decreased over time, reaching a lower value in the current survey (8.5%) than in 2003 (30.8%) and in 2005–2006 (25.5%). Conclusions: This study confirmed the anti-measles vaccination campaign success, which allowed for the increase in vaccination coverage and immunity levels against measles in the Florentine pediatric and adolescent population following the NPEMcR implementation.

Beliefs towards vaccination and trust in the scientific community in Italy

BACKGROUND

In 2017 the Italian government introduced compulsory vaccination for Italian school children for ten diseases, in response to an alarmingly decrease in coverage and measles outbreak. A hot social debate arose around the issue of the law. Studies on the opinion of Italians on this topic are rare, so we investigated the socio-cultural profile of Italians about beliefs towards vaccination.

METHODS

Data were extracted from the Italian section of the European Social Survey (ESS), conducted by the Italian National Institute for Public Policies Analysis during 2017. The main outcome assessed was the opinion about the supposed harmfulness of vaccines. We analysed the association between the outcome and a selected group of socio-cultural characteristics, with a specific interest in examining the interaction between our main outcome and the perceived trust in the scientific community in regards to vaccines. A principal component analysis was then performed for determining the socio-cultural profile of respondents.

RESULTS

Among the 2,626 subjects interviewed face to face, 19% believed that vaccines were harmful and 10% did not have trust in the scientific community in regards to vaccines. Out of the respondents who believed in the harmfulness of vaccines, 29% neither had trust in the scientific community. Principal Component Analysis suggested that this group (Anti-vax/science sceptic) was characterised by low participation in political and cultural life, being male, older of age and politically oriented towards the right. People agreeing about harmfulness of vaccines are mostly males, have a lower education level, poor attendance in political and cultural life and are politically oriented to the right.

CONCLUSIONS

The ESS survey is unique in its capacity to deal with emerging themes of the social debates. Results paint a picture of the opinions of Italians on vaccines. This profile may be useful for policymakers to design targeted vaccination campaigns and to intervene more efficaciously in the public debate.

Longitudinal profiling of the vaccination coverage in Brazil reveals a recent change in the patterns hallmarked by differential reduction across regions

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There has been a recent reduction in vaccination coverage across the Brazilian regions.

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The most relevant reduction in vaccination coverage has occurred in childhood immunization.

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Increased web searches for anti-vaccine material has been associated with the reduction in immunization coverage.

Objective

Vaccination coverage is decreasing worldwide, favoring the potential reemergence of vaccine-preventable diseases. In this study, we performed a longitudinal characterization of vaccination coverage in Brazil and compared the profiles between the distinct regions in the country to test whether there has been a substantial change over the last 5 years.

Methods

De-identified publicly available data were retrieved from the repository of the Brazilian Ministry of Health, comprising detailed information on vaccination coverage in all age groups between 1994 and 2019. The vaccination coverage for the whole country and for each Brazilian region, by year, was examined, and a time-series pattern analysis was performed.

Results

A significant decrease in overall vaccination coverage across the country regions was observed between 2017 and 2019, especially in childhood immunization. A reduction in BCG, hepatitis B, influenza, and rotavirus vaccine coverage was observed. Conversely, vaccines against measles, mumps, rubella, varicella, and meningococcus showed an increase in coverage. Region-specific changes in vaccination patterns within the study period were observed.

Conclusions

A substantial reduction in vaccination coverage was detected in Brazil, a country already highly susceptible to the emergence of epidemic infectious diseases. Continuing evaluation of the immunization program actions may help to improve vaccination coverage and prevent new epidemics.

Knowledge, attitudes and practices about vaccination in Trentino, Italy in 2019

Introduction: Vaccination is among the most important areas of progress in the worldwide history of public health. However, a crescent wave of anti-vaccine groups has grown in Western countries, especially in Italy, in the last two decades. Our aim was to evaluate adult's hesitancy and knowledge about vaccines and related diseases in Trentino-Alto Adige -the Italian region with the lowest vaccination coverages. Methods: We administered self-answered structured questionnaires in three malls in the Trentino province in June 2019. We collected demographic data and information on knowledge about vaccines, infectious diseases and attitude in seeking health information. We utilized a descriptive and multivariate analysis to investigate factors associated with vaccine hesitancy. Results: We collected 567 questionnaires, 18% of the people interviewed were hesitant toward vaccination and 16% were against mandatory vaccination. In the multivariate analysis a poor level of information, being younger than 60 years and being against compulsory vaccination were associated with vaccine hesitancy. Regarding information about vaccines, 76.5% of the people relied on physicians, and/or 49% navigated the internet, while social media are used by 16% of the study population. Though 41.5% searched information on official sites, only 14% knew the website VaccinarSì and 4.7% had visited it. Discussion: Compared to a previous study conducted in all of Italy except Trentino Alto Adige, the level of vaccination hesitancy was higher. It is important to utilize health professionals, the internet and especially social media to spread scientific information about vaccination.

Socioeconomic Determinants in Vaccine Hesitancy and Vaccine Refusal in Italy

Childhood vaccination has been a milestone in the control of infectious diseases. However, even in countries offering equal access to vaccination, a number of vaccine-preventable diseases have re-emerged. Suboptimal vaccination coverage has been called into question. The aim was to explore socioeconomic inequalities in vaccine hesitancy and outright refusal. Families with at least one child aged between 3 months and 7 years were involved through an online survey. Families were classified as provaccine, hesitant, or antivaccine. The association between socioeconomic determinants and hesitancy/refusal was investigated with a logistic-regression model. A total of 3865 questionnaires were collected: 64.0% of families were provaccine, 32.4% hesitant, and 3.6% antivaccine. Rising levels of perceived economic hardship were associated with hesitancy (adjusted odds ratio (AOR) from 1.34 to 1.59), and lower parental education was significantly associated with refusal (AOR from 1.89 to 3.39). Family economic hardship and parental education did not move in parallel. Economic hardship was a determinant of hesitancy. Lower education was a predictor of outright refusal without affecting hesitancy. These findings may serve as warnings, and further explanations of socioeconomic inequities are needed even in universal healthcare systems. Insight into these factors is necessary to improve convenience and remove potential access issues.

A Prospective Cohort Study on the Safety of Infant Pentavalent (DTwP-HBV-Hib) and Oral Polio Vaccines in Two South Indian Districts

BACKGROUND

Safety of pentavalent (DTwP-HBV-Hib) vaccine has been a public concern in India and other countries. This study attempted to document the association of serious adverse events following immunization (AEFI, including hospitalizations and deaths of all causes) with the 3 doses of pentavalent and oral poliovirus (OPV) vaccines.

METHODS

A cohort of 30,688 infants in 2 south Indian districts were enrolled and followed-up between October 2014 and May 2016, following their first vaccination with DTwP-HBV-Hib and OPV at public health facilities. During weekly follow-ups, by telephone or home visits, the serious AEFIs (hospitalizations and deaths) occurring any time after each vaccination until 4 weeks after third dose were documented. The incidence risk ratios (IRRs) of serious AEFIs in the first (days 0-6) and fourth weeks (days 21-27) after the vaccine doses were compared using the poisson regression analysis.

RESULTS

Of the 30,688 infants enrolled, 30,208 received their third doses of vaccines. During the 4-week periods following each vaccination, there were 365 hospitalizations and 17 deaths. Adjusted incidence risk ratio of 3 doses combined for post-vaccination serious AEFIs during the first week compared with fourth week was 0.8 [95% confidence interval: 0.6-1.0].

CONCLUSIONS

There was no increased risk of a serious AEFIs during the first week after any of the 3 doses of pentavalent and OPV vaccination compared with the fourth week. In the absence of any temporal clustering, mortality and hospitalization rates observed in vaccinated infants probably reflects the natural occurrence of such events.

Key steps in vaccine development

OBJECTIVE

The goal of a vaccine is to prime the immune response so the immune memory can facilitate a rapid response to adequately control the pathogen on natural infection and prevent disease manifestation. This article reviews the main elements that provide for the development of safe and effective vaccines.

DATA SOURCES

Literature covering target pathogen epidemiology, the key aspects of the functioning immune response underwriting target antigen selection, optimal vaccine formulation, preclinical and clinical trial studies necessary to deliver safe and efficacious immunization.

STUDY SELECTIONS

Whole live, inactivated, attenuated, or partial fractionated organism-based vaccines are discussed in respect of the balance of reactogenicity and immunogenicity. The use of adjuvants to compensate for reduced immunogenicity is described. The requirements from preclinical studies, including establishing a proof of principle in animal models, the design of clinical trials with healthy volunteers that lead to licensure and beyond are reviewed.

RESULTS

The 3 vaccine development phases, preclinical, clinical, and post-licensure, integrate the requirements to ensure safety, immunogenicity, and efficacy in the final licensed product. Continuing monitoring of efficacy and safety in the immunized populations is essential to sustain confidence in vaccination programs.

CONCLUSION

In an era of increasing vaccine hesitancy, the need for a better and widespread understanding of how immunization acts to counteract the continuing and changing risks from the pathogenic world is required. This demands a societal responsibility for obligate education on the benefits of vaccination, which as a medical intervention has saved more lives than any other procedure.

Elevated quinolinic acid levels in cerebrospinal fluid in subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE) is a rare neurodegenerative disorder caused by a persistent infection with aberrant measles virus. Indoleamine-2, 3-dioxygenase (IDO) initiates the increased production of kynurenine pathway (KP) metabolites quinolinic acid (QUIN), which has an excitotoxic effect for neurons. We measured serum IDO activity and cerebrospinal fluid (CSF) levels of QUIN. The CSF QUIN levels were significantly higher in SSPE patients than in controls, and increased according as neurological disability in a patient studied. Elevation of CSF QUIN and progression of SSPE indicate a pathological role of KP metabolism in the inflammatory neurodestruction.

Hyaluronic Acid Nanocapsules as a Platform for Needle-Free Vaccination

Vaccination faces many challenges nowadays, and among them the use of adjuvant molecules and needle-free administration are some of the most demanding. The combination of transcutaneous vaccination and nanomedicine through a rationally designed new-formulation could be the solution to this problem. This study focuses on this rational design. For this purpose, new hyaluronic acid nanocapsules (HA-NCs) have been developed. This new formulation has an oily nucleus with immunoadjuvant properties (due to α tocopherol) and a shell made of hyaluronic acid (HA) and decorated with ovalbumin (OVA) as the model antigen. The resulting nanocapsules are smaller than 100 nm, have a negative superficial charge and have a population that is homogeneously distributed. The systems show high colloidal stability in storage and physiological conditions and high OVA association without losing their integrity. The elevated interaction of the novel formulation with the immune system was demonstrated through complement activation and macrophage viability studies. Ex vivo studies using a pig skin model show the ability of these novel nanocapsules to penetrate and retain OVA in higher quantities in skin when compared to this antigen in the control solution. Due to these findings, HA-NCs are an interesting platform for needle-free vaccination.