Safety of vaccines used for routine immunization in the United States: An updated systematic review and meta-analysis

Umbrella review of the safety of Chikungunya vaccine platforms used in other vaccines

Chikungunya virus (CHIKV), transmitted through Aedes mosquitoes, is a significant global health concern. Various vaccine platforms have been explored to combat CHIKV, including formalin inactivation, live-attenuated strains, virus-like particles (VLPs), viral vectors, and mRNA technologies. This umbrella review synthesizes evidence on the safety profiles of vaccine platforms used in Chikungunya vaccines that have been applied in other vaccines, focusing on adverse events of special interest (AESI) in pregnant persons, children, and adolescents. A comprehensive overview of systematic reviews (SRs) was conducted. Results: Seven systematic reviews were included and complemented with primary studies. Vaccines like influenza, human papillomavirus (HPV), and COVID-19, which share platforms with Chikungunya vaccines, showed no significant increase in AESI. Moderate-to high-quality SRs supported favorable safety profiles. Vaccines sharing platforms with Chikungunya vaccines generally exhibit acceptable safety profiles in pregnant persons, children, and adolescents.

Factors associated with HPV vaccine hesitancy: A nationally representative cross-sectional study

BACKGROUND

HPV related tumors continue to be a global leading cause of cancer mainly due to cervical cancer (CC) burden. In Brazil, CC is the third most common cancer and the fourth highest cancer mortality rate among women. HPV vaccine mass immunization represents the current most promising intervention for CC prevention. It was first implemented in the Brazilian public health system in 2014, however, despite a history of excellent coverage for other vaccines, HPV vaccine uptake is below the necessary threshold for CC elimination. Identifying the factors that influence HPV vaccine hesitancy is an essential step to further develop strategies to improve vaccination coverage.

OBJECTIVES

The aim of this study is to provide insights into whether or not Brazilians are resistant to HPV vaccination and to determine the factors and variables that influence this decision.

METHODS

This is a population-based cross-sectional study which used quantitative methodology through personal interviews. A total of 2010 interviews were planned to result in error margins of 2 percentage points, more or less considering a 95 % confidence level, encompassing all five Brazilian regions. Cities of different sizes and complexities were included in the sample, as capitals and cities in both metropolitan and rural areas. The research was carried out with the Brazilian population aged 16 and over, interviewees were approached at points of population flow.

RESULTS

Between June 12th and 16th 2023, a total of 2010 personal interviews were done, with participants from all five Brazilian regions. The prevalence of vaccine resistance was 5.97 % (95 % confidence interval [CI], 4.93-7.23) among those interviewed. A multivariate analysis demonstrated greater resistance to the vaccine among men (prevalence ratios (PR): 1.58; 95 %CI 1.06-2.34; p: 0.023) and residents in the South region of the country (PR: 1.77; 95 %CI, 1.06-2.94; p: 0.028). The three main reasons for refusing the vaccine reported by the participants were: lack of knowledge about the HPV vaccine; difficulty in accessing the vaccine; and lack of vaccine prescription by health professionals. Safety was the main reason not to vaccinate, cited by 10 %.

CONCLUSIONS

Despite HPV vaccine availability in Brazil at the public health system, vaccination coverage remains below the target for both genders. However, according to this analysis, there is a low rate of HPV vaccination hesitancy in the country, being lack of knowledge, difficulty in accessing the vaccine and lack of vaccine prescription by health professionals the main obstacles to adequate adherence. The COVID-19 pandemic doesn't seem to have affected HPV vaccination resistance in the country. Proper strategies for vaccine implementation, including school-based programs, patient-provider communication and education, and integrated monitoring and evaluation strategies are needed, otherwise HPV vaccine programs run the risk of repeating the problems associated with Pap programs in Low- and Middle-Income Countries (LMICs): an efficient, life-saving tool underutilized for cancer prevention.

Gastroenteritis hospitalizations over 19 years before and after introduction of rotavirus vaccine in Japan: A nationwide claims database

BACKGROUND

Rotavirus is a major cause of pediatric gastroenteritis worldwide, leading to severe health outcomes. Rotavirus vaccines (RV) have introduced grobally, in Japan, introduced in 2010 as self-payment and in 2020 as public funding vaccine. This study evaluates the change of gastroenteritis hospitalization and intussusception.

METHODS

The descriptive study utilized JMDC claims database, focusing on 3 million children under 12 years from January 2005 to July 2023. The primary outcome was the incidence of all-cause gastroenteritis and rotavirus enteritis hospitalizations per 1000 person-year, with secondary outcomes including intussusception. Data were extracted using ICD-10 codes, and hospitalization rates were categorized into three periods: pre-vaccine (before October 2011), post-vaccine introduction (November 2011 to September 2020), and post-public funding (from October 2020). Statistical analyses included descriptive epidemiology, and interrupted time series (ITS) design.

RESULTS

The study included 3,085,932 children (51 % male, 49 % female), with a mean age of 4.16 years. The gastroenteritis hospitalization per 1000 person-year under five year old age was 12.0 pre-vaccine period to 4.8 post-public funding period with a 60 % decrease (p < 0.001). Under the same conditions, hospitalization for rotavirus enteritis was 5.8 pre-vaccine period to 2.5 post-public funding period with a 58 % decrease (p < 0.01). ITS analysis showed a further -0.2 % monthly decrease in rotavirus enteritis hospitalizations post-vaccine introduction (p = 0.007). No significant changes were found for intussusception trends before and after RV.

CONCLUSION

In this study, gastroenteritis hospitalizations and rotavirus enteritis hospitalizations in children significant decreased. Intussusception rate were unchanged throughout the study period.

Modeling Reemergence of Vaccine-Eliminated Infectious Diseases Under Declining Vaccination in the US

Importance

Widespread childhood vaccination has eliminated many infectious diseases in the US. However, vaccination rates are declining, and there are ongoing policy debates to reduce the childhood vaccine schedule, which may risk reemergence of previously eliminated infectious diseases.

Objective

To estimate the number of cases and complications in the US under scenarios of declining childhood vaccination for measles, rubella, poliomyelitis, and diphtheria.

Design, Setting, and Participants

A simulation model was used to assess the importation and dynamic spread of vaccine-preventable infectious diseases across 50 US states and the District of Columbia. The model was parameterized with data on area-specific estimates for demography, population immunity, and infectious disease importation risk. The model evaluated scenarios with different vaccination rates over a 25-year period. Inputs for current childhood vaccination rates were based on 2004-2023 data.

Main Outcomes and Measures

The primary outcomes were estimated cases of measles, rubella, poliomyelitis, and diphtheria in the US. The secondary outcomes were estimated rates of infection-related complications (postmeasles neurological sequelae, congenital rubella syndrome, paralytic poliomyelitis, hospitalization, and death) and the probability and timing for an infection to reestablish endemicity.

Results

At current state-level vaccination rates, the simulation model predicts measles may reestablish endemicity (83% of simulations; mean time of 20.9 years) with an estimated 851 300 cases (95% uncertainty interval [UI], 381 300 to 1.3 million cases) over 25 years. Under a scenario with a 10% decline in measles-mumps-rubella (MMR) vaccination, the model estimates 11.1 million (95% UI, 10.1-12.1 million) cases of measles over 25 years, whereas the model estimates only 5800 cases (95% UI, 3100-19 400 cases) with a 5% increase in MMR vaccination. Other vaccine-preventable diseases are unlikely to reestablish endemicity under current levels of vaccination. If routine childhood vaccination declined by 50%, the model predicts 51.2 million (95% UI, 49.7-52.5 million) cases of measles over a 25-year period, 9.9 million (95% UI, 6.4-13.0 million) cases of rubella, 4.3 million cases (95% UI, 4 cases to 21.5 million cases) of poliomyelitis, and 197 cases (95% UI, 1-1000 cases) of diphtheria. Under this scenario, the model predicts 51 200 cases (95% UI, 49 600-52 600 cases) with postmeasles neurological sequelae, 10 700 cases (95% UI, 6700-14 600 cases) of congenital rubella syndrome, 5400 cases (95% UI, 0-26 300 cases) of paralytic poliomyelitis, 10.3 million hospitalizations (95% UI, 9.9-10.5 million hospitalizations), and 159 200 deaths (95% UI, 151 200-164 700 deaths). In this scenario, measles became endemic at 4.9 years (95% UI, 4.3-5.6 years) and rubella became endemic at 18.1 years (95% UI, 17.0-19.6 years), whereas poliovirus returned to endemic levels in about half of simulations (56%) at an estimated 19.6 years (95% UI, 14.0-24.7 years). There was large variation across the US population.

Conclusions and Relevance

Based on estimates from this modeling study, declining childhood vaccination rates will increase the frequency and size of outbreaks of previously eliminated vaccine-preventable infections, eventually leading to their return to endemic levels. The timing and critical threshold for returning to endemicity will differ substantially by disease, with measles likely to be the first to return to endemic levels and may occur even under current vaccination levels without improved vaccine coverage and public health response. These findings support the need to continue routine childhood vaccination at high coverage to prevent resurgence of vaccine-preventable infectious diseases in the US.

Vaccinome Landscape in Nearly 620 000 Patients With Diabetes

CONTEXT

Type 1 (T1D) and type 2 diabetes (T2D) are associated with an elevated incidence of infectious diseases and a higher risk of infections-related hospitalization and death.

OBJECTIVE

In this study, we delineated the "vaccinome" landscape obtained with a large immunization schedule offered by the Regional Government of Lombardy in a cohort of 618 396 patients with diabetes (T1D and T2D).

METHODS

Between September 2021 and September 2022, immunization coverage for influenza, meningococcus, pneumococcus, and herpes zoster was obtained from the public computerized registry of the health care system of Lombardy Region (Italy) in 618 396 patients with diabetes and in 9 534 087 subjects without diabetes. Type of diabetes, age, mortality, and hospitalizations were retrospectively analyzed in vaccinated and unvaccinated patients.

RESULTS

Among patients with diabetes (T1D and T2D), 44.6% received the influenza vaccine, 10.9% the pneumococcal vaccine, 2.5% the antimeningococcus vaccine, and 0.7% the antizoster vaccine. Patients with diabetes immunized for influenza, zoster, and meningococcus showed a 2-fold overall reduction in mortality risk and a decrease in hospitalizations. A 3-fold lower risk of mortality and a decrease in hospitalizations for both cardiac and pulmonary causes were also observed after influenza, zoster, and meningococcus immunization in older patients with diabetes.

CONCLUSION

Immunization coverage is still far from the recommended targets in patients with diabetes. Despite this, influenza vaccination protected nearly 3800 per 100 000 patients with diabetes from risk of death. The overall impressive decrease in mortality and hospitalizations observed in vaccinated patients strengthens the need for scaling up the "vaccinome" landscape in patients with diabetes.

Australia's rotavirus immunisation program: Impact on acute gastroenteritis and intussusception hospitalisations over 13 years

BACKGROUND

Australia was one of the first countries to include rotavirus vaccines in its National Immunisation Program, in 2007. We compared trends in acute gastroenteritis (AGE) and intussusception-coded hospitalisations over 13-year post-vaccine period against five-year pre-vaccine baseline.

METHODS

In a descriptive before-after study, incidence of hospitalisations with ICD-code of rotavirus AGE (A08.0), other AGE (K52, A01-A09 excluding A08.0) or intussusception (K56.1) between 2002 and 2020 was calculated using population denominators by age and Indigenous status. We used 2002-2006 as pre-vaccine baseline and calculated Incidence Rate Ratios [IRRs] for 2008-2019 and 2020.

FINDINGS

In children aged <5 years, mean annual hospitalisation rate/100,000 decreased by 85% for rotavirus-coded AGE, from 248.3 in 2002-2006 to 37.6 (IRR 0.15; 95% CI 0.15-0.16) in 2008-2019 (61.4% for Indigenous children, from 680.2 to 262.2), and 46% for other AGE, from 1274.5 to 689.1 (IRR 0.54; CI 0.54-0.55), decreasing further in 2020 to 6.3 (rotavirus-coded) and 445.0 (other AGE). Rates for rotavirus-coded and other AGE declined in 2008-2019 in those aged 5-<20 years (IRR 0.52; CI 0.49-0.56 and 0.86; CI 0.85-0.87, respectively), but increased in 20-<65 years (IRR 2.38; CI 2.01-2.83 and 1.15; CI 1.15-1.16) and ≥65 years (IRR 2.24; CI 1.91-2.62 and 1.24; CI 1.23-1.25). Average annual hospitalisation rate for intussusception in infants was similar in pre-vaccine and post-vaccine periods (IRR 0.97; CI 0.90-1.04).

CONCLUSION

Over a 13-year period post-rotavirus vaccine introduction we document major sustained declines in hospitalisations coded as rotavirus and other AGE in age groups <20 years, with no change in intussusception hospitalisation rates in infants. Despite small increases in AGE hospitalisations in adults, likely due to increased PCR testing, our findings are consistent with highly favourable risk benefit ratio at whole-of-population level in Australia.

A Rapid Systematic Review of U.S. Food and Drug Administration-Authorized COVID-19 Treatments

Background

The coronavirus disease 2019 (COVID-19) pandemic era saw numerous treatments authorized for emergency use by the United States (US) Food and Drug Administration (FDA). The purpose of the review was to determine if convalescent plasma, antivirals, or monoclonal antibodies are associated with serious adverse events (SAEs) and, if so, which specific populations are at risk.

Methods

PubMed, ClinicalTrials.gov, and the FDA submission database were searched through December 2023, and the Infectious Diseases Society of America guidelines, international COVID Network Meta-analysis database, and systematic reviews were reference mined to identify controlled studies with at least 1 US site. Reviewers abstracted study characteristics, number of patients experiencing each type of SAE, and methods of adverse event collection and reporting.

Results

Fifty-four studies met inclusion criteria, including 31 randomized controlled trials. We found insufficient evidence of association of any SAE with antivirals and spike protein receptor-binding antibodies. In patients hospitalized with COVID-19, the monoclonal antibody tocilizumab, an interleukin 6 inhibitor, may be associated with elevated risk of neutropenia (moderate certainty) and infection (limited certainty). Convalescent plasma may be associated with thrombotic events (limited certainty) as well as bleeding events and infection in patients with hematologic cancers (moderate certainty). Inclusion of studies without a US site could potentially change the findings.

Conclusions

Severe COVID-19 infection may have serious consequences, especially in hospitalized patients with comorbidities. These consequences may be confused with toxicities of the interventions. Based on our analysis, approved treatments for COVID-19 should be prescribed as clinically indicated, although continued vigilance is warranted to identify rare and potentially significant toxicities that may arise in clinical practice.

Clinical Trials Registration

PROSPERO (CRD42023467821).

Adverse Events Following Haemophilus influenzae Type b (Hib) Monovalent Vaccines in Zhejiang Province, China, from 2017 to 2023

BACKGROUND

The Haemophilus influenzae type b (Hib) vaccination has well-established safety and efficacy in preventing Hib and reducing related morbidity and mortality worldwide. China has a high disease burden of Hib yet a low coverage rate of Hib vaccines and remains the only WHO member country not including the Hib vaccine in its National Immunization Program (NIP), partly due to insufficient surveillance data on its safety. This study analyzed all adverse events following immunization (AEFIs) after Hib monovalent vaccination in Zhejiang Province from 2017 to 2023 to provide evidence for formulating relevant immunization strategies.

METHODS

Hib vaccine-related AEFIs in Zhejiang Province from 1 January 2017, to 31 December 2023, were collected through the Chinese National AEFI Information System (CNAEFIS) for a descriptive epidemiological analysis.

RESULTS

From 2017 to 2023, a total of 1740 Hib vaccine-related AEFIs were reported (incidence rate: 63.01/100,000 doses) (95%CI: 60.12/100,000 doses-66.04/100,000 doses), including 1577 common adverse reactions (57.10/100,000 doses) (95%CI: 54.35/100,000 doses-59.99/100,000 doses), 139 rare adverse reactions (5.03/100,000 doses) (95%CI: 4.26/100,000 doses-5.94/100,000 doses), and 24 coincidental events (0.87/100,000 doses) (95%CI: 0.58/100,000 doses-1.29/100,000 doses). Most of the AEFIs were common adverse reactions that manifested mainly as fever, injection site redness and swelling, and crying. AEFIs were more likely to occur in male participants under the age of one, in summer and autumn, and during the booster immunity stage. The top three regions with the highest reported incidence rates of AEFIs were Jiaxing City (86.61/100,000 doses) (95%CI: 74.44/100,000 doses-100.77/100,000 doses), Hangzhou City (81.29/100,000 doses) (95%CI: 72.56/100,000 doses-91.07/100,000 doses), and Taizhou City (66.62/100,000 doses) (95%CI: 58.24/100,000 doses-76.21/100,000 doses).

CONCLUSIONS

Our findings provide preliminary evidence of the safety profile of the Hib vaccine at a provincial level, which adds further support for its broader implementation in other provinces. Future multi-center studies are needed to construct a comprehensive vaccine evaluation framework and make multi-criteria decisions on the feasibility of incorporating the Hib vaccine into China's NIP.

[Pneumonia and pregnancy]

Acute community-acquired pneumonia (CAP) during pregnancy is a frequently encountered and potentially severe condition. CAP incidence and ecology are unchanged during pregnancy as compared with the overall young adult population. Risk factors specifically identified in pregnant women include advanced gestational age, asthma, anemia and repeated courses of corticosteroid therapy for fetal lung maturation. The clinical presentation of CAP is not altered during pregnancy. Key points in the pregnant host encompass: (i) reduced maternal tolerance to hypoxia, due to physiological adaptations during pregnancy; (ii) heightened severity of some infections, notably viral pneumonias such as influenza, varicella or SARS-CoV-2 pneumonia; (iii) potentially deleterious fetal repercussions of infection and maternal hypoxia, with an increased risk of premature delivery and prematurity; (iv) the need for specific attention to the risk of fetal irradiation in the performance of possibly repeated radiological examinations and (v) therapeutic specificities arising from the possible embryo-fetal toxicity of certain anti-infectious agents. CAP prevention is premised on compliance with universal hygiene measures and on vaccination, which guarantees protection against severe forms of pneumonia not only in the mother (Streptococcus pneumoniae, seasonal flu, chickenpox, COVID-19), but also in the child during the first few months of life (whooping cough, RSV).

Pertussis Vaccination for Adults: An Updated Guide for Clinicians

Pertussis, or whooping cough, is a highly contagious respiratory infection caused by the Gram-negative bacterium Bordetella pertussis. Although traditionally associated with children, pertussis is increasingly prevalent among adults, particularly those with comorbidities or weakened immune systems, where it can lead to severe complications. Diagnosing pertussis in adults can be challenging due to its nonspecific symptoms, underreporting, and the limited sensitivity of available diagnostic tests. While treatment with macrolides is generally effective, it may not significantly alter the clinical course of the disease, and growing concerns about macrolide resistance are emerging. Vaccination remains the cornerstone of prevention, offering proven immunogenicity, efficacy, and safety. However, vaccination uptake remains low, partly due to limited patient awareness and insufficient prioritization by healthcare professionals. This review aims to provide clinicians with critical insights into pertussis epidemiology, vaccination strategies, and the latest guideline recommendations, empowering them to engage in meaningful discussions with adult patients and advocate for increased vaccination to combat this often-overlooked infection.

A review of safety and immunogenicity of a novel measles, mumps, rubella (MMR) vaccine

Measles, mumps, and rubella (MMR) are highly infectious viral diseases affecting young children and have high secondary attack rates. Present MMR vaccines show consistent seroconversion rates for anti-measles and anti-rubella antibodies with variable responses for anti-mumps antibodies. Most common strains for MMR vaccines, currently available in India, are the Edmonston-Zagreb measles strain, Leningrad Zagreb (L-Z) mumps strain, and the RA 27/3 rubella strain. L-Z strain of mumps virus has been found to be associated with aseptic meningitis by different studies from different parts of the world including India. Recently, a novel freeze-dried MMR vaccine developed by Zydus Lifesciences (Zyvac MMR) contains Edmonston Zagreb measles strain, Hoshino mumps strain, and RA 27/3 rubella strain. The Hoshino strain is WHO approved and was found to induce interferon gamma production. This review article aims to provide a comprehensive appraisal of the data available on the safety and immunogenicity of the novel MMR vaccine.

Vaccination of pregnant women: an overview of European policies and strategies to promote it

Maternal immunization is a valuable tool for protecting mother and unborn child from vaccine-preventable diseases. However, the implementation of strategies for vaccinating pregnant women has only recently gained traction. This work is aimed at providing an overview of European vaccination strategies and gathering evidence on interventions enhancing vaccination knowledge, attitudes, and behaviors (KAB) in pregnant women. To summarize current pregnancy vaccination strategies in Europe, we consulted literature, institutional national health system websites, and the ECDC Vaccine Scheduler. The review of evidence on interventions targeting pregnant women's vaccination KAB was performed by searching primary studies on PubMed and Web of Science. The 27 EU member states offer various vaccinations in pregnancy, but only 10 recommend all of these: tetanus, pertussis, diphtheria, influenza, and COVID-19, albeit with different administration schedules. The literature review included 7 studies, 3 from Italy and 4 from other European countries (UK, Netherlands, Greece, Poland, and Ukraine). They were conducted in various settings such as childbirth preparation courses, prenatal visits, and online platforms, and all included educational interventions providing information on vaccine safety and efficacy during pregnancy. Knowledge about vaccines and vaccine-preventable diseases, generally low in the pre-intervention period, increased post-intervention, with a rise in awareness of the risks associated with infectious diseases and the recommended vaccines, a reduction in vaccine-related misinformation, and a greater propensity to vaccinate both newborns and themselves. Furthermore, there was a significant increase in adherence to recommended vaccinations, particularly among those with higher educational levels. However, vaccine hesitancy persisted, influenced by factors such as fear of adverse events and the lack of recommendations from healthcare providers. Variations in pregnancy vaccination strategies across Europe emphasize the importance of establishing a unified framework to optimize maternal and fetal health outcomes through evidence-based policies. Educational interventions may positively impact pregnant women's KAB, therefore promoting vaccination uptake.

Immunogenicity and Safety of the Recombinant Adjuvanted Herpes Zoster Vaccine in Patients with Chronic Lymphocytic Leukemia and Multiple Myeloma

BACKGROUND/OBJECTIVES

Patients with chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) are susceptible to viral infections, including varicella-zoster virus (VZV) reactivation due to both disease-related and treatment-induced immunosuppression. The recombinant adjuvanted herpes zoster vaccine (RZV) has shown high efficacy in immunocompetent adults, but immunogenicity data in CLL and MM patients are limited. This study evaluates the immunogenicity and safety of RZV in this population.

METHODS

Patients with CLL and MM vaccinated with RZV (administered in two doses at least one month apart) were included in the study. Pre- and post-vaccination anti-VZV IgM and IgG antibody levels were measured to assess immunogenicity, and adverse events (AEs) were captured for safety evaluation.

RESULTS

Seventy-eight patients received both vaccine doses, and 71 had post-vaccination samples. Most of the patients were IgM seronegative and IgG seropositive before vaccination. Pre-vaccination IgG levels were higher in CLL patients compared to MM patients (p = 0.001), while post-vaccination IgG levels significantly increased in both CLL (p < 0.0001) and MM (p < 0.0001) patients. In actively treated CLL patients, pre-vaccination IgG levels were significantly lower than in not actively treated patients (p = 0.002). Post-vaccination IgG levels were lower in MM patients receiving antiviral prophylaxis concurrently with the vaccination (p = 0.013). AEs were reported in 49.4% of patients after the first dose and 48.7% after the second dose, mostly mild (local or low-grade systemic). One case of immune thrombocytopenia was noted.

CONCLUSIONS

RZV demonstrated strong immunogenicity and acceptable safety in CLL and MM patients, significantly boosting IgG levels, even in actively treated or heavily pretreated patients.

Physiological Response to the COVID-19 Vaccine: Insights From a Prospective, Randomized, Single-Blinded, Crossover Trial

BACKGROUND

Rapid development and implementation of vaccines constituted a crucial step in containing the COVID-19 pandemic. A comprehensive understanding of physiological responses to these vaccines is important to build trust in medicine.

OBJECTIVE

This study aims to investigate temporal dynamics before and after COVID-19 vaccination in 4 physiological parameters as well as the duration of menstrual cycle phases.

METHODS

In a prospective trial, 17,825 adults in the Netherlands wore a medical device on their wrist for up to 9 months. The device recorded their physiological signals and synchronized with a complementary smartphone app. By means of multilevel quadratic regression, we examined changes in wearable-recorded breathing rate, wrist skin temperature, heart rate, heart rate variability, and objectively assessed the duration of menstrual cycle phases in menstruating participants to assess the effects of COVID-19 vaccination.

RESULTS

The recorded physiological signals demonstrated short-term increases in breathing rate and heart rate after COVID-19 vaccination followed by a prompt rebound to baseline levels likely reflecting biological mechanisms accompanying the immune response to vaccination. No sex differences were evident in the measured physiological responses. In menstruating participants, we found a 0.8% decrease in the duration of the menstrual phase following vaccination.

CONCLUSIONS

The observed short-term changes suggest that COVID-19 vaccines are not associated with long-term biophysical issues. Taken together, our work provides valuable insights into continuous fluctuations of physiological responses to vaccination and highlights the importance of digital solutions in health care.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1186/s13063-021-05241-5.

Evaluating Factors That Influence Influenza Vaccination Uptake among Pregnant People in a Medically Underserved Area in Washington State

INTRODUCTION

Despite substantial evidence demonstrating the effectiveness of influenza vaccines, only 38.6% of the adult United States population received an influenza vaccine during the 2023-2024 flu season. Vaccination rates are typically lower among U.S. minority groups, and in 2022, pregnant persons from U.S. minority racial and ethnic groups showed a decrease in influenza vaccine coverage.

METHODS

A survey was conducted with residents of Yakima County, Washington, which is home to one of the state's largest percentages of people who identify as Hispanic or Latino/a. The objective was to evaluate the uptake of influenza vaccine among pregnant persons. Surveys were sent to a random sample of 3000 residential mailing addresses. Of the 500 respondents, 244 (52.1%) reported that they had been pregnant, with those identifying as Hispanic or Latino/a constituting 23.8% of this total. Only 62 (26.2%) reported being immunized against influenza during pregnancy. Respondents who were immunized against influenza chose to be vaccinated to protect themselves from the flu (85.5%, n = 53); because a healthcare provider recommended getting vaccinated (85.5%, n = 53); to protect the baby from the flu (82.3%, n = 51); because it was available for free or low cost (62.9%, n = 39); and because vaccination was convenient (54.8%, n = 34). Qualitative evaluation identified that participants who were not vaccinated against influenza during pregnancy believed the vaccination was not needed, was not recommended by a healthcare provider, was difficult to access, they were against vaccination in general, or they were concerned about the safety and ingredients of the vaccine.

CONCLUSION

Barriers to vaccination identified in this study included vaccine distrust, lack of awareness, and concerns about vaccine efficacy and safety. Healthcare providers can help address these concerns by providing education and recommendations about the importance of influenza vaccination during pregnancy.

Health Promotion and Chronic Disease Prevention at the Workplace

The concept of workplace safety and health has focused largely on preventing accidents and on minimizing hazardous exposures. However, because workers spend a substantial part of their waking hours at the workplace, the potential to influence the health of a large proportion of the world's population through the workplace is enormous. The opportunities to carry out health promotion and chronic disease prevention activities at the workplace are countless, including (a) health screening; (b) tobacco cessation activities; (c) the promotion of healthy food choices and weight loss; (d) active breaks with physical exercise in terms of microexercise, enhancement of infrastructure to stimulate physical activity, and organization of work tasks to facilitate incidental physical activity; and (e) routine vaccinations. This review discusses the key factors necessary to implement health promotion and chronic disease prevention programs at the workplace (SWOLE model) and discusses the different foci and possibilities with respect to the differing nature of work for the blue- versus white-collar workforce.

2023 clinical practice guidelines on autism spectrum disorder in children and adolescents in Singapore

Introduction

Autism is a neurodevelopmental condition that is increasing in prevalence worldwide. There has been an exponential increase in autism-related research since 2010, when the first Singapore Clinical Practice Guidelines (CPG) on autism was published. Understanding of autism has since evolved to adopt a lifespan approach beyond that of a childhood condition. The aim of this CPG was to provide an updated set of recommendations for children and adolescents to aid clinical practice for professionals.

Method

A multidisciplinary workgroup that comprised representatives from various sectors worked on this CPG. Clinical questions were organised into 10 different sections, each with its own subgroup of members. Seventeen existing international guidelines were evaluated using the Appraisal of Guidelines for REsearch & Evaluation II (AGREE-II) framework, of which 4 met criteria to act as references. Literature review across multiple databases was conducted between January 2011 to 2023; Grading of Recommendations, Assessment, Development and Evaluation (GRADE-like) methodology was used to synthesise evidence. Recommendation statements were derived, following Delphi-style consensus surveys among the workgroup. The draft guidelines underwent external review and public consultation before being formalised.

Results

Recommendation and good practice statements pertaining to care of children and adolescents on the autism spectrum across 10 different sections were developed. Evidence matrices complement these recommendations and detail relevant evidence behind each recommendation statement.

Conclusion

It is intended for these guidelines to promote effective management and healthcare services for children and adolescents on the autism spectrum, by reinforcing good and evidence-based clinical practice within our national context.

Do vaccines cause epilepsy? Review of cases in the National Vaccine Injury Compensation Program

OBJECTIVE

The National Childhood Vaccine Injury Act of 1986 created the National Vaccine Injury Compensation Program (VICP), a no-fault alternative to the traditional tort system. Since 1988, the total compensation paid exceeds $5 billion. Although epilepsy is one of the leading reasons for filing a claim, there has been no review of the process and validity of the legal outcomes given current medical information. The objectives were to review the evolution of the VICP program in regard to vaccine-related epilepsy and assess the rationale behind decisions made by the court.

METHODS

Publicly available cases involving epilepsy claims in the VICP were searched through Westlaw and the US Court of Federal Claims websites. All published reports were reviewed for petitioner's theories supporting vaccine-induced epilepsy, respondent's counterarguments, the final decision regarding compensation, and the rationale underlying these decisions. The primary goal was to determine which factors went into decisions regarding whether vaccines caused epilepsy.

RESULTS

Since the first epilepsy case in 1989, there have been many changes in the program, including the removal of residual seizure disorder as a vaccine-related injury, publication of the Althen prongs, release of the acellular form of pertussis, and recognition that in genetic conditions the underlying genetic abnormality rather than the immunization causes epilepsy. We identified 532 unique cases with epilepsy: 105 with infantile spasms and 427 with epilepsy without infantile spasms. The petitioners' experts often espoused outdated, erroneous causation theories that lacked an acceptable medical or scientific foundation and were frequently criticized by the court.

SIGNIFICANCE

Despite the lack of epidemiological or mechanistic evidence indicating that childhood vaccines covered by the VICP result in or aggravate epilepsy, these cases continue to be adjudicated. After 35 years of intense litigation, it is time to reconsider whether epilepsy should continue to be a compensable vaccine-induced injury.

Institutional trust is a distinct construct related to vaccine hesitancy and refusal

BACKGROUND

Vaccine hesitancy is driven by a heterogeneous and changing set of psychological, social and historical phenomena, requiring multidisciplinary approaches to its study and intervention. Past research has brought to light instances of both interpersonal and institutional trust playing an important role in vaccine uptake. However, no comprehensive study to date has specifically assessed the relative importance of these two categories of trust as they relate to vaccine behaviors and attitudes.

METHODS

In this paper, we examine the relationship between interpersonal and institutional trust and four measures related to COVID-19 vaccine hesitancy and one measure related to general vaccine hesitancy. We hypothesize that, across measures, individuals with vaccine hesitant attitudes and behaviors have lower trust-especially in institutions-than those who are not hesitant. We test this hypothesis in a sample of 1541 Canadians.

RESULTS

A deficit in both interpersonal and institutional trust was associated with higher levels of vaccine hesitant attitudes and behaviors. However, institutional trust was significantly lower than interpersonal trust in those with high hesitancy scores, suggesting that the two types of trust can be thought of as distinct constructs in the context of vaccine hesitancy.

CONCLUSIONS

Based on our findings, we suggest that diminished institutional trust plays a crucial role in vaccine hesitancy. We propose that this may contribute to a tendency to instead place trust in interpersonally propagated belief systems, which may be more strongly misaligned with mainstream evidence and thus support vaccine hesitancy attitudes. We offer strategies rooted in these observations for creating public health messages designed to enhance vaccine uptake.

Efficacy and safety of the recombinant zoster vaccine: A systematic review and meta-analysis

In this systematic review with meta-analysis, the efficacy, effectiveness, and safety of the new GSK recombinant zoster vaccine (RZV) were assessed.Twenty three publications reporting on 14 studies were selected, including 2 pivotal RCTs in older immunocompetent adults (ZOE-50 and ZOE-70), 4 RCTs on immunocompromised patients (haematopoietic stem cell transplantation (HSCT), haematological malignancies, solid tumour, and renal transplantation), and 8 observational studies. Vaccine efficacy of RZV against herpes zoster (HZ) and postherpetic neuralgia (PHN) was very high in immunocompetent older adults (respectively 94% and 91.2% in adults ≥50 years and 91.3% and 88.8% in adults ≥70 years). However, the number needed to vaccinate (NNV) was relatively high (between 32 and 36 for HZ and between 261 and 335 for PHN). Slow waning of the vaccine efficacy has been described after a median follow-up of 10 years after vaccination. In patients after HSCT, vaccine efficacy of RZV against HZ was lower compared to immunocompetent adults (68.2%), while vaccine efficacy of RZV against PHN was similar (89.3%). Higher incidences of HZ and PHN in patients after HSCT resulted in higher absolute reduction of cases and lower NNV (respectively 10 and 115). Observational studies confirmed a good vaccine effectiveness, albeit lower than in RCTs (ranging between 70% and 85%). No safety signal was identified neither in RCTs with immunocompetent or immunocompromised adults nor in observational studies and post-marketing surveillance. Increased reactogenicity after RZV vaccination, limited in extent and duration, did not result in low second dose compliance.

Conclusion

Although vaccine efficacy in RCTs and effectiveness in the real world has been reported to be good, it needs to be stressed that high numbers of immunocompetent adults need to be vaccinated to prevent HZ and PHN. Due to higher incidence, more acceptable NNVs were calculated in immunocompromised adults after HSCT.

Human Papillomavirus Vaccines

Human papillomavirus (HPV) vaccines are highly effective in preventing the transmission of HPV and thus downstream HPV-related lower genital tract neoplasias. First introduced in 2006, the HPV vaccine has demonstrated clinical efficacy in both men and women. Several commercially available vaccines now exist, but only one is available in the United States. Both prelicensure and postlicensure studies demonstrate robust safety profiles. HPV vaccines should be made available to everyone between the ages of 9 and 26 years of age. Newer vaccination recommendations in expanded populations rely on patient-provider shared decision making. Currently, available HPV vaccines offer little therapeutic benefit. Recent research has identified several new DNA vaccines and delivery modifications with early demonstrated success at eliminating prevalent HPV infections and precancerous lesions. Despite the success of the HPV vaccine, vaccination hesitancy and disinformation continue to threaten our ability to eliminate these deadly cancers. Informational, behavioral, and environmental interventions have mixed success in increasing vaccination rates, but several strategies do exist to increase rates of vaccination.

High coverage and timeliness of vaccination of children under 6 years of age in Risaralda, Colombia

This study determined the coverage and timeliness of immunization in children <6 y from Risaralda, Colombia. A retrospective cross-sectional study evaluated data from a vaccination coverage and timeliness verification survey conducted in 2019, including 2457 children <6 y from Risaralda, Colombia. Variables included demographics, a record of vaccinations included in the Colombian Vaccination Plan, and date of immunization. Vaccination was defined as timely until 29 d after the day established by the plan. Coverage was over 95% for all vaccinations, except the boosters of diphtheria/pertussis/tetanus (DTP) and oral polio at 18 months (91.0%), influenza (85.6%), and yellow fever (49.2%). Most surveyed children demonstrated very high timeliness of vaccination, with values close to, or over, 90%, although there were exceptions for pentavalent (DTP+Haemophilus influenzae type B+hepatitis B) and polio vaccines at 6 months (79.4%), influenza (85.6%), and yellow fever (49.2%). Before the COVID-19 pandemic, Colombian Vaccination Plan demonstrated high coverage and timeliness of vaccination of children <6 y of age; however, timeliness for the third dose of DTP-Hib-HBV and polio showed opportunities for improvement.

An Overview of Selected Bacterial Infections in Cancer, Their Virulence Factors, and Some Aspects of Infection Management

In cancer development and its clinical course, bacteria can be involved in etiology and secondary infection. Regarding etiology, various epidemiological studies have revealed that Helicobacter pylori can directly impact gastric carcinogenesis. The Helicobacter pylori-associated virulence factor cytotoxin-associated gene A perhaps plays an important role through different mechanisms such as aberrant DNA methylation, activation of nuclear factor kappa B, and modulation of the Wnt/β-catenin signaling pathway. Many other bacteria, including Salmonella and Pseudomonas, can also affect Wnt/β-catenin signaling. Although Helicobacter pylori is involved in both gastric adenocarcinoma and mucosa-associated lymphoid tissue lymphoma, its role in the latter disease is more complicated. Among other bacterial species, Chlamydia is linked with a diverse range of diseases including cancers of different sites. The cellular organizations of Chlamydia are highly complex. Interestingly, Escherichia coli is believed to be associated with colon cancer development. Microorganisms such as Escherichia coli and Pseudomonas aeruginosa are frequently isolated from secondary infections in cancer patients. In these patients, the common sites of infection are the respiratory, gastrointestinal, and urinary tracts. There is an alarming rise in infections with multidrug-resistant bacteria and the scarcity of suitable antimicrobial agents adversely influences prognosis. Therefore, effective implementation of antimicrobial stewardship strategies is important in cancer patients.

Influences of sociodemographic characteristics and parental HPV vaccination hesitancy on HPV vaccination coverage in five US states

BACKGROUND

In the United States (US), half of new human papillomavirus (HPV) infections occur among young people aged 15-24 years. Despite the effectiveness of HPV vaccination in protecting against HPV-associated cancers, its coverage among adolescents remains suboptimal. This study examined the association of sociodemographic characteristics and HPV vaccination hesitancy with HPV vaccination coverage in five US states with disproportionately low adolescent coverage rates compared to the national average.

METHODS

Responses to an online Qualtrics survey from 926 parents of children aged 9-17 years in Arkansas, Mississippi, Missouri, Tennessee, and Southern Illinois in July 2021 were analyzed using multivariate logistic regression to estimate the association of sociodemographic characteristics and HPV vaccination hesitancy with HPV vaccination coverage.

RESULTS

Of the parents, 78 % were female, 76 % were non-Hispanic White, 61.9 % lived in rural areas, 22 % were classified as HPV vaccine hesitant, and 42 % had vaccinated their oldest child between the ages of 9-17 years against HPV. Children of vaccine hesitant parents were less likely to have received any doses of the HPV vaccine than children of non-vaccine hesitant parents (AOR: 0.17, 95 % CI:0.11-0.27). Male children were less likely to have initiated the HPV vaccine series than female children (AOR: 0.70, 95 % CI:0.50-0.97). Older children (13-17 vs 9-12 years), receiving the meningococcal conjugate or most recent seasonal influenza vaccine were all associated with higher likelihoods of receiving any doses of the HPV vaccine (AOR: 6.01, 95 % CI:3.98-9.08; AOR: 2.24, 95 % CI:1.27-3.95; AOR: 2.41, 95 % CI:1.73-3.36, respectively).

CONCLUSIONS

Adolescent HPV vaccination coverage remains low in our targeted states. Children's age, sex, and parental vaccine hesitancy were significantly associated with likelihood of HPV vaccination. These findings offer the opportunity for targeted interventions among parents in regions with low vaccine uptake and underscore the importance of developing and implementing strategies to address parental HPV vaccination hesitancy to improve uptake in the US.

Association of periconceptional or pregnancy exposure of HPV vaccination and adverse pregnancy outcomes: a systematic review and meta-analysis with trial sequential analysis

Objective: To evaluate whether periconceptional or pregnancy exposure of human papillomavirus (HPV) vaccination would increase the risk of adverse pregnancy outcomes. Methods: The PubMed, Web of Science, Embase, the Cochrane Library of clinical trials were searched from inception to March 2023. We computed relative risk (RR) and 95% confidence intervals (CIs) and prediction intervals (PIs) regarding the association between HPV vaccination in periconceptional period or during pregnancy and the risks of adverse pregnancy outcomes by using R software Version 4.1.2 and STATA Version 12.0. A trial sequential analysis (TSA) was performed with TSA v0.9.5.10 Beta software. Results: Four randomized controlled trials (RCTs) and eight cohort studies were included in this meta-analysis. Analysis of RCTs showed that HPV vaccination in periconceptional period or during pregnancy did not increase the risks of spontaneous abortion (RR = 1.152, 95% CI: 0.909-1.460, 95% PI: 0.442-3.000), birth defects (RR = 1.171, 95% CI: 0.802-1.709, 95% PI: 0.320-4.342), stillbirth (RR = 1.053, 95% CI: 0.616-1.800, 95% PI: 0.318-3.540), preterm birth (RR = 0.940, 95% CI: 0.670-1.318) and ectopic pregnancy (RR = 0.807, 95% CI: 0.353-1.842, 95% PI: 0.128-5.335). In cohort studies, periconceptional or pregnancy exposures of HPV vaccine were not associated with the increased risk of spontaneous abortion (RR = 0.987, 95% CI: 0.854-1.140, 95% PI: 0.652-1.493), birth defects (RR = 0.960, 95% CI: 0.697-1.322, 95% PI: 0.371-2.480), stillbirth (RR = 1.033, 95% CI: 0.651-1.639, 95% PI: 0.052-21.064), small size for gestational age (SGA) (RR = 0.971, 95% CI: 0.873-1.081, 95% PI: 0.657-1.462) and preterm birth (RR = 0.977, 95% CI: 0.874-1.092, 95% PI: 0.651-1.444). Conclusion: HPV vaccine exposures in periconceptional period or during pregnancy did not increase the risks of adverse pregnancy outcomes, including spontaneous abortion, birth defects, stillbirth, SGA, preterm birth and ectopic pregnancy. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023399777.

Defensive information processing and nonadherence to health-protective behaviors

PLAIN LANGUAGE SUMMARY

In this issue of Cancer, Clarke et al. measure defensive information processing (DIP) to avoid fecal immunochemical testing for colorectal cancer. DIP is a way of reducing the negative psychological effects of threats such as cancer and may influence health-protective behaviors such as the completion of recommended cancer screening. This editorial complements Clarke et al.'s study with a discussion of interventions for decreasing DIP around cancer screening and other health-protective recommendations.

Barriers and facilitators of vaccine hesitancy for COVID-19, influenza, and pertussis during pregnancy and in mothers of infants under two years: An umbrella review

BACKGROUND

Vaccination during pregnancy has been repeatedly demonstrated to be safe and effective in protecting against infection and associated harms for the mother, developing baby, and subsequent infant. However, maternal vaccination uptake remains low compared to the general population.

OBJECTIVES

An umbrella review to explore the barriers and facilitators to Influenza, Pertussis and COVID-19 vaccination during pregnancy and within 2 years after childbirth, and to inform interventions to encourage uptake (PROSPERO registration number: CRD42022327624).

METHODS

Ten databases were searched for systematic reviews published between 2009 and April 2022 exploring the predictors of vaccination or effectiveness of interventions to improve vaccination for Pertussis, Influenza, or COVD-19. Both pregnant women and mothers of infants under two years were included. Barriers and facilitators were organised using the WHO model of determinants of vaccine hesitancy through narrative synthesis, the Joanna Briggs Institute checklist assessed review quality, and the degree of overlap of primary studies was calculated.

RESULTS

19 reviews were included. Considerable overlap was found especially for intervention reviews, and the quality of the included reviews and their primary studies varied. Sociodemographic factors were specifically researched in the context of COVID-19, exerting a small but consistent effect on vaccination. Concerns around the safety of vaccination particularly for the developing baby were a main barrier. While key facilitators included recommendation from a healthcare professional, previous vaccination, knowledge around vaccination, and communication with and support from social groups. Intervention reviews indicated multi-component interventions involving human interaction to be most effective.

CONCLUSION

The main barriers and facilitators for Influenza, Pertussis and COVID-19 vaccination have been identified and constitute the foundation for policy development at the international level. Ethnicity, socioeconomic status, concerns about vaccine safety and side effects, and lack of healthcare professionals' recommendations, are the most relevant factors of vaccine hesitancy. Adapting educational interventions to specific populations, person-to-person interaction, healthcare professionals' involvement, and interpersonal support are important strategies to improve uptake.

Modern Approaches in Immunoprophylaxis of Infectious Diseases During Pregnancy

Every year more countries recommend vaccination for pregnant women. Nowadays, the spectrum of vaccines that can be used during pregnancy is expanding. Experts of the Union of Pediatricians of Russia have completely updated the section about the pregnant women immunoprophylaxis within updating clinical guidelines on normal pregnancy management. This section is presented in the following article.

Safety of Vaccination within First Year of Life-The Experience of One General Medicine Center

Vaccines represent an important preventive strategy in paediatric populations, but the rate of vaccination has been constantly declining in the last decade. Concerns about vaccines' safety represent one of the main causes of vaccine hesitancy among parents. The aim of this study was the analysis of the immediate adverse reactions induced by vaccines included in the national program of immunization for the first year of life. Method: Eighty-one children born between 1st of January 2018 and 31st of March 2019 were included. The vaccination refusal rate, and incidence and severity of adverse effects induced by three mandatory vaccines (Hexavalent, Prevenar 13 and MMR) were analyzed. The level of parents' education and the sources of information that were consulted in order to understand the adverse effects were also analyzed. Results and conclusions: The rate of adverse events was lower than 30% of the total number of doses, and most of them were mild. The incidence and severity of vaccine-induced adverse effects were correlated with prematurity. The vaccine hesitancy rate was lower than the national one, possibly due to a high level of education and good information provided by doctors that might have led to parents' concerns regarding vaccination being answered.

Barriers and facilitators to vaccination for COVID-19, pertussis, and influenza during pregnancy: Protocol for an umbrella review

Pregnant women are particularly vulnerable to infection. Furthermore, infection from pertussis, influenza and COVID-19 increases the likelihood of adverse consequences to the mother and developing baby such as stillbirth, ICU admission, and pre-term caesarean birth. Increased rates of transmission and risk of adverse consequences from infection justifies the provision of national maternal vaccination programmes. Additionally, maternal vaccination helps protect the infant until they are able to receive their own vaccinations; a time when they are most at risk of mortality from influenza and pertussis. Vaccination during pregnancy has been repeatedly demonstrated as safe and effective in reducing harm, although rates of uptake remain low compared to the general population. The current protocol describes the methodology for an umbrella review aiming to explore the barriers and facilitators of vaccination during pregnancy for pertussis, influenza, and COVID-19. Systematic reviews that investigate the barriers and facilitators of at least one of either pertussis, influenza, or COVID-19 will be included in this review. Multiple databases will be searched, and included reviews assessed for quality (using the Joanna Briggs Institute (JBI) quality assessment for systematic reviews) and degree of overlap of included primary studies. Included reviews will be analysed according to the WHO SAGE model of determinants of vaccine hesitancy and separated by whether these explore influenza and pertussis, or COVID-19. The outcomes of this review will help inform the development of interventions to increase uptake of vaccination during pregnancy, and on whether interventions need to be tailored depending on the infectious disease. The key findings will identify the specific barriers and facilitators of vaccination hesitancy by considering contextual influences (e.g. sociodemographic variables), individual/social group influences (e.g. trust in the institutions), and vaccine-specific issues (e.g. safety and recommendations).

Ocular Inflammatory Reactions following an Inactivated SARS-CoV-2 Vaccine: A Four Case Series

PURPOSE

To report a four-case series of ocular adverse events post an inactivated COVID-19 vaccination in China.

METHODS

The four patients exhibited ocular inflammatory reactions on the same day after receiving an inactivated SARS-CoV-2 vaccine.

RESULTS

All patients underwent detailed ophthalmic examinations, with the medical diagnosis of Vogt-Koyanagi-Harada, Ponser-Schlossman, secondary post-inflammatory glaucoma, and iridocyclitis, respectively. No patients had any other underlying medical conditions causing the ocular complications. The ocular inflammatory reactions of these four patients were resolved with the administration of oral or topical corticosteroids.

CONCLUSION

Our cases remind the ophthalmologist that adverse ocular events may happen after the administration of SARS-CoV-2 vaccine. Since the ocular complications could be resolved with the corticosteroid treatment, the events were considered to be inflammatory reactions caused by the SARS-CoV-2 vaccine.

Safety of measles and pertussis-containing vaccines in children with autism spectrum disorders

OBJECTIVES

To determine whether children aged 4-7 years with a diagnosis of autism spectrum disorders (ASD) were at increased risk of fever, febrile seizures, or emergency department (ED) visits following measles- or pertussis-containing vaccines compared with children without ASD.

METHODS

The study included children born between 1995-2012, aged 4-7 years at vaccination, and members of six healthcare delivery systems within Vaccine Safety Datalink. We conducted self-controlled risk interval analyses comparing rates of outcomes in risk and control intervals within each group defined by ASD status, and then compared outcome rates between children with and without ASD, in risk and control intervals, by estimating difference-in-differences using logistic regressions.

RESULTS

The study included 14,947 children with ASD and 1,650,041 children without ASD. After measles- or pertussis-containing vaccination, there were no differences in association between children with and without ASD for fever (ratio of rate ratio for measles-containing vaccine = 1.07, 95% CI 0.58-1.96; for pertussis-containing vaccine = 1.16, 95% CI 0.63-2.15) or ED visits (ratio of rate ratio for measles-containing vaccine = 1.11, 95% CI 0.80-1.54; for pertussis-containing vaccine = 0.87, 95% CI 0.59-1.28). Febrile seizures were rare. Pertussis-containing vaccines were associated with small increased risk of febrile seizures in children without ASD.

CONCLUSION

Children with ASD were not at increased risk for fever or ED visits compared with children without ASD following measles- or pertussis-containing vaccines. These results may provide further reassurance that these vaccines are safe for all children, including those with ASD.

Neuralgic Amyotrophy with Concomitant Hereditary Neuropathy with Liability to Pressure Palsy as a Cause of Dropped Shoulder in a Child after Human Papillomavirus Vaccination: A Case Report

Hereditary neuropathy with liability to pressure palsy (HNPP) makes nerves increasingly susceptible to mechanical pressure at entrapment sites. Neuralgic amyotrophy (NA) can cause sudden regional weakness following events to which the patient is immunologically predisposed, such as vaccination. However, NA related to human papilloma virus (HPV) vaccination is seldom reported. We describe the case of a child with NA as the cause of a dropped shoulder following the administration of the HPV vaccine. Underlying asymptomatic HNPP was confirmed in this patient based on the electrodiagnostic findings and genetic analysis. We speculate that HPV vaccination elicited an immune-mediated inflammatory response, resulting in NA. Our patient with pre-existing HNPP might be vulnerable to the occurrence of an immune-mediated NA, which caused the dropped shoulder.

Death after the Administration of COVID-19 Vaccines Approved by EMA: Has a Causal Relationship Been Demonstrated?

More than eight billion doses of COVID-19 vaccines have been administered globally so far and 44.29% of people are fully vaccinated. Pre-authorization clinical trials were carried out and the safety of vaccines is still continuously monitored through post-commercialization surveillance. However, some people are afraid of vaccine side effects, claiming they could lead to death, and hesitate to get vaccinated. Herein, a literature review of COVID-19-vaccine-related deaths has been carried out according to the PRISMA standards to understand if there is a causal relationship between vaccination and death and to highlight the real extent of such events. There have been 55 cases of death after COVID-19 vaccination reported and a causal relationship has been excluded in 17 cases. In the remaining cases, the causal link between the vaccine and the death was not specified (8) or considered possible (15), probable (1), or very probable/demonstrated (14). The causes of deaths among these cases were: vaccine-induced immune thrombotic thrombocytopenia (VITT) (32), myocarditis (3), ADEM (1), myocardial infarction (1), and rhabdomyolysis (1). In such cases, the demonstration of a causal relationship is not obvious, and more studies, especially with post-mortem investigations, are needed to deepen understanding of the possible pathophysiological mechanisms of fatal vaccine side effects. In any event, given the scarcity of fatal cases, the benefits of vaccination outweigh the risks and the scientific community needs to be cohesive in asserting that vaccination is fundamental to containing the spread of SARS-CoV-2.

Maternal HPV Infection: Effects on Pregnancy Outcome

The human papilloma virus (HPV) infection, caused by a ubiquitous virus typically transmitted through the direct contact of infected organs, either through the skin or mucosa, is the most common sexually transmitted infection, placing young women at a high risk of contracting it. Although the vast majority of cases spontaneously clear within 1-2 years, persistent HPV infection remains a serious concern, as it has repeatedly been linked to the development of multiple malignancies, including cervical, anogenital, and oropharyngeal cancers. Additionally, more recent data suggest a harmful effect of HPV infection on pregnancy. As the maternal hormonal environment and immune system undergo significant changes during pregnancy, the persistence of HPV is arguably favored. Various studies have reported an increased risk of adverse pregnancy outcomes among HPV-positive women, with the clinical impact encompassing a range of conditions, including preterm birth, miscarriage, pregnancy-induced hypertensive disorders (PIHD), intrauterine growth restriction (IUGR), low birth weight, the premature rupture of membranes (PROM), and fetal death. Therefore, understanding the mechanisms employed by HPV that negatively impact pregnancy and assessing potential approaches to counteract them would be of interest in the quest to optimize pregnancy outcomes and improve child survival and health.

The impact of COVID-19 in pregnancy: Part II. Vaccination to pregnant women

Effective strategies are urgently needed to decrease the risk of untoward outcomes of pregnant women with severe acute respiratory syndrome coronavirus 2 (coronavirus disease 2019 [COVID-19]) infection. Pregnant women are a vulnerable population to infectious disease pandemics with dramatically increased infectious diseases-related serious complications, such as the need of hospitalizations, the need of admission to intensive care unit, and the final disease-related death compared with those nonpregnant counterparts or those pregnant women without infection. Several studies have shown that vaccinations in pregnancy are a safe and highly effective strategy, not only for pregnant women but also for fetus and/or newborn because of the passive transplacental transfer of antibodies to the offspring. Active and passive prevention of infectious diseases is approved as effective strategies for women who attempt to become pregnant or during pregnancy. Despite the large and proven scientific evidence, pregnant women still puzzle over whether they should get vaccinated. The question therefore arises: Why are pregnant women so reluctant to receive vaccination? The explanation is more likely in the way that the benefits of vaccination have been communicated "confusedly." In fact, like virtually all clinical trials, all the COVID-19 vaccine trials have excluded pregnant and lactating women from participating, contributing to uncertainty of safety and efficacy in COVID-19 vaccines that have been well prepared and available for the general adult population worldwide. Moreover, messenger RNA vaccine is a relatively brand-new vaccine, and experience with this type of vaccine is still scarce. It is hard to overcome this innovation deadlock. The knowledge and awareness of pregnant women who are at risk, and full information on the knowledge of vaccines and related preventable diseases in pregnant women may avoid hesitancy and increase vaccine acceptance. The current review is a part two addressing the impact of COVID-19 on pregnant women. We focus on the up-to-date information about the application of vaccination on pregnant women, especially during this COVID-19 pandemic.

Update on Influenza Vaccines: Needs and Progress

Influenza is an annual seasonal epidemic, and occasionally pandemic, respiratory disease that causes considerable morbidity and mortality worldwide. Despite the widespread availability of safe and effective vaccines since the 1950s, this virus continues to pose a significant public health threat. Variable and often weak vaccine effectiveness, antigenic drift and shift, and vaccine hesitancy are some of the obstacles that must be overcome to control this disease. In this article, we briefly review current influenza vaccines, address safety concerns and the need for newer influenza vaccines of higher efficacy, and discuss efforts to create broadly protective, universal influenza vaccines.