Influences of Vitamin A on Vaccine Immunogenicity and Efficacy

Maternal immunization and vitamin A sufficiency impact sow primary adaptive immunity and passive protection to nursing piglets against porcine epidemic diarrhea virus infection

Porcine epidemic diarrhea virus (PEDV) causes a highly contagious enteric disease with major economic losses to swine production worldwide. Due to the immaturity of the neonatal piglet immune system and given the high virulence of PEDV, improving passive lactogenic immunity is the best approach to protect suckling piglets against the lethal infection. We tested whether oral vitamin A (VA) supplementation and PEDV exposure of gestating and lactating VA-deficient (VAD) sows would enhance their primary immune responses and boost passive lactogenic protection against the PEDV challenge of their piglets. We demonstrated that PEDV inoculation of pregnant VAD sows in the third trimester provided higher levels of lactogenic protection of piglets as demonstrated by >87% survival rates of their litters compared with <10% in mock litters and that VA supplementation to VAD sows further improved the piglets' survival rates to >98%. We observed significantly elevated PEDV IgA and IgG antibody (Ab) titers and Ab-secreting cells (ASCs) in VA-sufficient (VAS)+PEDV and VAD+VA+PEDV sows, with the latter maintaining higher Ab titers in blood prior to parturition and in blood and milk throughout lactation. The litters of VAD+VA+PEDV sows also had the highest serum PEDV-neutralizing Ab titers at piglet post-challenge days (PCD) 0 and 7, coinciding with higher PEDV IgA ASCs and Ab titers in the blood and milk of their sows, suggesting an immunomodulatory role of VA in sows. Thus, sows that delivered sufficient lactogenic immunity to their piglets provided the highest passive protection against the PEDV challenge. Maternal immunization during pregnancy (± VA) and VA sufficiency enhanced the sow primary immune responses, expression of gut-mammary gland trafficking molecules, and passive protection of their offspring. Our findings are relevant to understanding the role of VA in the Ab responses to oral attenuated vaccines that are critical for successful maternal vaccination programs against enteric infections in infants and young animals.

Nutritional Status Link with Polioseronegativity Among Children from Poliomyelitis Transmission High-Risk Area of the Democratic Republic of the Congo (DRC)

Background

Malnutrition is identified as a risk-factor for insufficient polioseroconversion in the context of a vaccine-derived polio virus (VDPV) outbreak prone region. To assess the prevalence of malnutrition and its link to poliovirus insufficient immunity, a cross-sectional household survey was conducted in the regions of Haut- Lomami and Tanganyika, DRC.

Methods

In March 2018, we included 968 healthy children aged 6 to 59 months from eight out of 27 districts. Selection of study locations within these districts was done using a stratified random sampling method, where villages were chosen based on habitat characteristics identified from satellite images. Consent was obtained verbally in the preferred language of the participant (French or Swahili) by interviewers who received specific training for this task. Furthermore, participants contributed a dried blood spot sample, collected via finger prick. To assess malnutrition, we measured height and weight, applying WHO criteria to determine rates of underweight, wasting, and stunting. The assessment of immunity to poliovirus types 1, 2, and 3 through the detection of neutralizing antibodies was carried out at the CDC in Atlanta, USA.

Results

Of the study population, we found 24.7% underweight, 54.8% stunted, and 15.4% wasted. With IC95%, underweight (OR=1.50; [1.11-2.03]), and the non-administration of vitamin A (OR=1.96; [1.52-2.54]) were significantly associated with seronegativity to polioserotype 1. Underweight (OR=1.64; [1.20-2.24]) and the non-administration of vitamin A (OR=1.55; [1.20-2.01]) were significantly associated with seronegativity to polioserotype 2. Underweight (OR=1.50; [1.11-2.03]), and the non-administration of vitamin A (OR=1.80. [1.38-2.35]) were significantly associated with seronegativity to polioserotype 3. Underweight (OR=1.68; IC95% [1.10-2.57]) and the non-administration of vitamin A (OR=1.82; IC95% [1.30-2.55]) were significantly associated with seronegativity to all polioserotypes.

Conclusion

This study reveals a significant association between underweight and polioseronegativity in children. In order to reduce vaccine failures in high-risk areas, an integrated approach by vaccination and nutrition programs should be adopted.

Prediction Model with Validation for Polioseronegativity in Malnourished Children from Poliomyelitis Transmission High-Risk Area of the Democratic Republic of the Congo (DRC)

Background

Malnutrition is identified as a risk factor for insufficient polio seroconversion in the context of a vaccine-derived poliovirus (VDPV) outbreak-prone region. In the Democratic Republic of Congo (DRC), underweight decreased from 31% (in 2001) to 26% (in 2018). Since 2004, VDPV serotype 2 outbreaks (cVDPV2) have been documented and were geographically limited around the Haut-Lomami and Tanganyika Provinces.

Methods

To develop and validate a predictive model for poliomyelitis vaccine response in malnourished infants, a cross-sectional household study was carried out in the Haut-Lomami and Tanganyika provinces. Healthy children aged 6 to 59 months (n=968) were enrolled from eight health zones (HZ) out of 27, in March 2018. We performed a bivariate and multivariate logistics analysis. Final models were selected using a stepwise Wald method, and variables were selected based on the criterion p < 0.05. The association between nutritional variables, explaining polio seronegativity for the three serotypes, was assessed using the receiver operating characteristic curve (ROC curve).

Results

Factors significantly associated with seronegativity to the three polio serotypes were underweight, non-administration of vitamin A, and the age group of 12 to 59 months. The sensitivity was 10.5%, and its specificity was 96.4% while the positive predictive values (PPV) and negative (PNV) were 62.7% and 65.3%, respectively. We found a convergence of the curves of the initial sample and two split samples. Based on the comparison of the overlapping confidence intervals of the ROC curve, we concluded that our prediction model is valid.

Conclusion

This study proposed the first tool which variables are easy to collect by any health worker in charge of vaccination or in charge of nutrition. It will bring on top, the collaboration between the Immunization and the Nutritional programs in DRC integration policy, and its replicability in other low- and middle-income countries with endemic poliovirus.

Exploring the Effects of Vitamin D and Vitamin A Levels on the Response to COVID-19 Vaccine

COVID-19 vaccines were developed at an unprecedented speed in history. The factors affecting the response to COVID-19 vaccines are not clear. Herein, the effects of vitamin D and vitamin A (retinol) levels on the response to the BNT162b2 vaccine were explored. A total of 124 vaccine recipients were recruited from the general population attending vaccination centers in Irbid, Jordan. Blood samples were collected immediately before receiving the first vaccine dose (D0) and three weeks later (D21). Baseline (D0) levels of 25-hydroxyvitamin D [25(OH)D], retinol, and SARS-CoV-2 S1 IgG antibodies were measured with ELISA. The response to the BNT162b2 vaccine was tested by measuring the levels and avidity of SARS-CoV-2 S1 IgG antibodies on D21. The participants were divided into two groups, unexposed and exposed, based on the D0 SARS-CoV-2 antibody results. No significant correlation was found between the levels of 25(OH)D or retinol and the levels, avidity, or fold increase of antibodies in both groups. Similarly, no significant difference in antibody response was found between 25(OH)D status groups, retinol status groups, or combined status groups. These findings show that the baseline vitamin D or vitamin A levels have no effect on the short-term response to a single dose of BNT162b2 vaccine.

Factors associated with pentavalent vaccine coverage among 12-23-month-old children in Afghanistan: A cross-sectional study

INTRODUCTION

This study aimed to identify the factors associated with the coverage of the third dose of pentavalent vaccine (Penta3) among children aged 12-23 months in Afghanistan.

METHODS

The data of 3,040 children aged 12-23 months were taken from the Afghanistan Health Survey 2018, including characteristics of the children and their households, household heads, and mothers/primary care givers. Adjusted odds ratios (AORs) and 95% confidence intervals (CIs) were estimated using a logistic model. Multivariable stepwise logistic regression analysis with forward-selection (Model 1) and backward-selection (Model 2) was performed using variables that showed significant differences by bivariate analysis.

RESULTS

The coverage of Penta3 among 12-23-month-old children was 82.3%. Factors associated with Penta3 coverage in the two models of multivariable analysis were 18-23 months old compared to 12-17 months old; having no diarrhea in the last two weeks compared to having diarrhea; no bipedal edema compared to having edema; taking vitamin A supplement; 1-2 children under five years in a household compared to three or more; distance from residence to the nearest health facility ≤2 hours on foot; having a radio; having a TV; educated heads of households; non-smoking of heads of households; and literacy of mothers/primary caregivers.

CONCLUSIONS

Penta3 coverage among 12-23-month-old children improved but was still lower than the target. Primary education should be provided to all children throughout the country. TV and radio are useful tools for providing health information. Mobile outreach programs and the establishment of new health facilities should be promoted to improve access to health service for all people in Afghanistan.

Factors associated with incomplete vaccination and negative antibody test results for measles, mumps, and hepatitis A among children followed in the MINA-BRAZIL cohort

Vaccination coverage has been dropping in Brazil and other countries. In addition, immune responses after vaccination may not be homogeneous, varying according to sociodemographic and clinical factors. Understanding the determinants of incomplete vaccination and negative antibody test results may contribute to the development of strategies to improve vaccination effectiveness. In this study, we aimed to investigate the frequency of vaccine adherence, factors associated with incomplete vaccination for measles, mumps, rubella (MMR) and hepatitis A, and factors associated with the seronegative test results for measles, mumps and hepatitis A at 2 years of age. This was a population-based cohort that addressed health conditions and mother/infant nutrition in Cruzeiro do Sul city, Brazil. Vaccination data were obtained from official certificates of immunization. The children underwent blood collection at the two-year-old follow-up visit; the samples were analyzed using commercially available kits to measure seropositivity for measles, mumps, and hepatitis A. We used modified Poisson regression models adjusted for covariates to identify factors associated with incomplete vaccination and negative serology after vaccination. Out of the 825 children included in the study, adherence to the vaccine was 90.6% for MMR, 76.7% for the MMRV (MMR + varicella), and 74.9% for the hepatitis A vaccine. For MMR, after the adjustment for covariates, factors associated with incomplete vaccination included: white-skinned mother; paid maternity leave; raising more than one child; lower number of antenatal consultations; and attending childcare. For hepatitis A, the factors included: white-skinned mother and not having a cohabiting partner. The factors with statistically significant association with a negative antibody test result included: receiving Bolsa Familia allowance for measles and mumps; incomplete vaccination for measles; and vitamin A deficiency for mumps. Strategies to improve the efficiency of vaccine programs are urgently needed. These include improvements in communication about vaccine safety and efficacy, and amplification of access to primary care facilities, prioritizing children exposed to the sociodemographic factors identified in this study. Additionally, sociodemographic factors and vitamin A deficiency may impact the immune responses to vaccines, leading to an increased risk of potentially severe and preventable diseases.

Vitamins, microelements and the immune system: current standpoint in the fight against coronavirus disease 2019

Coronavirus disease 2019 (COVID-19) is an acute respiratory disease associated with severe systemic inflammation. The optimal status of vitamins and microelements is considered crucial for the proper functioning of the immune system and necessary for successful recovery. Most patients with respiratory distress in COVID-19 are vitamin and microelement deficient, with vitamin D and Se deficiency being the most common. Anyway, various micronutrient supplements are widely and arbitrarily used for prevention or in the treatment of COVID-19. We aimed to summarise current knowledge about molecular and physiological mechanisms of vitamins (D, A, C, B₆, B₉ and B₁₂) and microelements (Se, Zn, Cu and Fe) involved in the immune system regulation in consideration with COVID-19 pathogenesis, as well as recent findings related to their usage and effects in the prevention and treatment of COVID-19. In the early course of the pandemic, several, mainly observational, studies reported an association of some micronutrients, such as vitamin C, D and Zn, with severity reduction and survival improvement. Still, emerging randomised controlled trials showed no effect of vitamin D on hospitalisation length and no effect of vitamin C and Zn on symptom reduction. Up to date, there is evidence neither for nor against the use of micronutrients in the treatment of COVID-19. The doses that exceed the recommended for the general population and age group should not be used, except in clinical trials. Benefits of supplementation are primarily expected in populations prone to micronutrient deficiencies, who are, as well, at a higher risk of worse outcomes in COVID-19.

Immune Impairment Associated with Vitamin A Deficiency: Insights from Clinical Studies and Animal Model Research

Vitamin A (VA) is critical for many biological processes, including embryonic development, hormone production and function, the maintenance and modulation of immunity, and the homeostasis of epithelium and mucosa. Specifically, VA affects cell integrity, cytokine production, innate immune cell activation, antigen presentation, and lymphocyte trafficking to mucosal surfaces. VA also has been reported to influence the gut microbiota composition and diversity. Consequently, VA deficiency (VAD) results in the imbalanced production of inflammatory and immunomodulatory cytokines, intestinal inflammation, weakened mucosal barrier functions, reduced reactive oxygen species (ROS) and disruption of the gut microbiome. Although VAD is primarily known to cause xerophthalmia, its role in the impairment of anti-infectious defense mechanisms is less defined. Infectious diseases lead to temporary anorexia and lower dietary intake; furthermore, they adversely affect VA status by interfering with VA absorption, utilization and excretion. Thus, there is a tri-directional relationship between VAD, immune response and infections, as VAD affects immune response and predisposes the host to infection, and infection decreases the intestinal absorption of the VA, thereby contributing to secondary VAD development. This has been demonstrated using nutritional and clinical studies, radiotracer studies and knockout animal models. An in-depth understanding of the relationship between VAD, immune response, gut microbiota and infections is critical for optimizing vaccine efficacy and the development of effective immunization programs for countries with high prevalence of VAD. Therefore, in this review, we have comprehensively summarized the existing knowledge regarding VAD impacts on immune responses to infections and post vaccination. We have detailed pathological conditions associated with clinical and subclinical VAD, gut microbiome adaptation to VAD and VAD effects on the immune responses to infection and vaccines.

Retinoid metabolism: new insights

Vitamin A (retinol) is a critical micronutrient required for the control of stem cell functions, cell differentiation, and cell metabolism in many different cell types, both during embryogenesis and in the adult organism. However, we must obtain vitamin A from food sources. Thus, the uptake and metabolism of vitamin A by intestinal epithelial cells, the storage of vitamin A in the liver, and the metabolism of vitamin A in target cells to more biologically active metabolites, such as retinoic acid (RA) and 4-oxo-RA, must be precisely regulated. Here, I will discuss the enzymes that metabolize vitamin A to RA and the cytochrome P450 Cyp26 family of enzymes that further oxidize RA. Because much progress has been made in understanding the regulation of ALDH1a2 (RALDH2) actions in the intestine, one focus of this review is on the metabolism of vitamin A in intestinal epithelial cells and dendritic cells. Another focus is on recent data that 4-oxo-RA is a ligand required for the maintenance of hematopoietic stem cell dormancy and the important role of RARβ (RARB) in these stem cells. Despite this progress, many questions remain in this research area, which links vitamin A metabolism to nutrition, immune functions, developmental biology, and nuclear receptor pharmacology.

Pestilence and famine: Continuing down the vicious cycle with COVID-19

Despite the fact that we produce enough food to feed everyone on Earth, world hunger is on the rise. On the other side of the table, the obesity crisis also weighs heavily. Malnutrition is less about food than about socioeconomic factors such as conflict, poverty, and global disasters such as climate change and the novel Coronavirus Disease 2019 (COVID-19) pandemic. Nutrition and infectious disease exist in an intricate dance. Adequate and balanced nutrition is critical for appropriate response to infection and any changes in the balance can serve as a tipping point for the next pandemic. On the other hand, pandemics, such as COVID-19, lead to greater malnutrition. Both over- and undernutrition increase severity of disease, alter vaccine effectiveness, and potentially create conditions for viral mutation and adaptation-further driving the disease and famine vicious cycle. These long-term health and socioeconomic repercussions have direct effects at individual and global levels and lead to long-term consequences. Therefore, investing in and strengthening public health, pandemic prevention, and nutrition programs become vital at a much more complex systems level.

Retinol Binding Protein, Sunlight Hours, and the Influenza Virus-Specific Immune Response

Healthy pediatric immune responses depend on adequate vitamin A and D levels. Relationships between solar ultraviolet B (UVB) radiation and vitamin D are well understood, while relationships between sunlight, vitamin A, and its serum escort, retinol binding protein (RBP), are not. A pediatric clinical study enrolled 2–8-year-old children at various times between September 2016 and March 2017, inclusive, in Memphis, Tennessee. A serum sample from each child was then assayed to examine the influence of season on vitamin levels. We found that RBP and RBP/retinol molar ratios decreased in winter months and RBP/retinol ratios correlated positively with the average daily sunlight hours per month. A food frequency questionnaire given to parents/guardians indicated a shift in dietary intake from plant-based foods to animal-based foods by children between winter and spring months. This translated to higher retinol and zinc (integral to RBP–transthyretin–retinol complexes) in the spring, perhaps explaining the seasonal influence on RBP/retinol. RBP and retinol were associated positively with IgG/IgM and IgA/IgM ratios. RBP and retinol, but not 25(OH)D, also correlated positively with influenza virus-specific antibodies. Retinol correlated negatively, while 25(OH)D correlated positively, with certain serum cytokine/chemokine levels. Significant differences in 25(OH)D, immunoglobulin ratios, and cytokines/chemokines were observed between black and white children. In sum, seasonal changes in dietary foods rich in retinol and zinc may have influenced RBP levels, which in turn influenced innate and adaptive immune responses. Results encourage routine monitoring and reporting of season, RBP, and vitamin levels in future clinical studies, as seasons may affect sunlight exposures, diet, vitamin levels, and immune protection against infectious disease.

Impact of Diet and Lifestyle on Vaccine Efficacy in Adults Aged 55 and Older: A Review

Context

Age-related declines in immune system function, including vaccine responsiveness, are well established. Dietary and lifestyle factors have been investigated in human clinical trials and observational studies for their effects on vaccine response.

Objective

The review intended to assess dietary and lifestyle factors that can modulate vaccine response in a population aged 55 years or older or in a population with an average age of 55 years or older.

Design

The research team performed a narrative review of studies occurring up until May 2021 by searching electronic PubMed databases.

Results

The review findings suggest that two factors may have clinically relevant effects on vaccine response: regular aerobic exercise and psychological environmental stressors, in particular caregiving stress, which studies have consistently found can have a positive and negative effect or association, respectively. In addition, micronutrients used in combination as well as microbiome-targeted interventions show mostly promising results. Other factors may yet be relevant but very few studies have been done.

Conclusions

Heterogeneity of study design, small sample sizes, and other challenges mean that strong conclusions remain elusive. Further study is needed as well as improvements in study design. However, there are indications that certain dietary and lifestyle factors influence vaccine effectiveness.

Hypothesis: Low Vitamin A and D Levels Worsen Clinical Outcomes When Children with Sickle Cell Disease Encounter Parvovirus B19

Human parvovirus B19 causes life-threatening anemia due to transient red cell aplasia (TRCA) in individuals with sickle cell disease (SCD). Children with SCD experiencing profound anemia during TRCA often require red blood cell transfusions and hospitalization. The prevalence of vitamin deficiencies in SCD is high and deficiencies are associated with respiratory and pain symptoms, but the effects of vitamins on acute infection with parvovirus B19 remain unclear. We performed a clinical study in which 20 SCD patients hospitalized with parvovirus B19 infections (Day 0) were monitored over a 120-day time course to query relationships between vitamins A and D and clinical outcomes. There were significant negative correlations between Day 0 vitamin levels and disease consequences (e.g., red blood cell transfusion requirements, inflammatory cytokines). There were significant positive correlations (i) between Day 0 vitamins and peak virus-specific antibodies in nasal wash, and (ii) between Day 0 virus-specific serum plus nasal wash antibodies and absolute reticulocyte counts. There was a significant negative correlation between Day 0 virus-specific serum antibodies and virus loads. To explain the results, we propose circular and complex mechanisms. Low baseline vitamin levels may weaken virus-specific immune responses to permit virus amplification and reticulocyte loss; consequent damage may further reduce vitamin levels and virus-specific immunity. While the complex benefits of vitamins are not fully understood, we propose that maintenance of replete vitamin A and D levels in children with SCD will serve as prophylaxis against parvovirus B19-induced TRCA complications.

Vaccines, Adjuvants and Key Factors for Mucosal Immune Response

Vaccines are the most effective tool to control infectious diseases, which provoke significant morbidity and mortality. Most vaccines are administered through the parenteral route and can elicit a robust systemic humoral response, but they induce a weak T-cell-mediated immunity and are poor inducers of mucosal protection. Considering that most pathogens enter the body through mucosal surfaces, a vaccine that elicits protection in the first site of contact between the host and the pathogen is promising. However, despite the advantages of mucosal vaccines as good options to confer protection on the mucosal surface, only a few mucosal vaccines are currently approved. In this review, we discuss the impact of vaccine administration in different mucosal surfaces; how appropriate adjuvants enhance the induction of protective mucosal immunity and other factors that can influence the mucosal immune response to vaccines. This article is protected by copyright. All rights reserved.

COVID-19 vaccines in patients with cancer: immunogenicity, efficacy and safety

Patients with cancer have a higher risk of severe coronavirus disease (COVID-19) and associated mortality than the general population. Owing to this increased risk, patients with cancer have been prioritized for COVID-19 vaccination globally, for both primary and booster vaccinations. However, given that these patients were not included in the pivotal clinical trials, considerable uncertainty remains regarding vaccine efficacy, and the extent of humoral and cellular immune responses in these patients, as well as the risks of vaccine-related adverse events. In this Review, we summarize the current knowledge generated in studies conducted since COVID-19 vaccines first became available. We also highlight critical points that might affect vaccine efficacy in patients with cancer in the future.

The Influence of Time of Day of Vaccination with BNT162b2 on the Adverse Drug Reactions and Efficacy of Humoral Response against SARS-CoV-2 in an Observational Study of Young Adults

An increasing body of evidence from both academic and clinical studies shows that time-of-day exposure to antigens might significantly alter and modulate the development of adaptive immune responses. Considering the immense impact of the COVID-19 pandemic on global health and the diminished efficacy of vaccination in selected populations, such as older and immunocompromised patients, it is critical to search for the most optimal conditions for mounting immune responses against SARS-CoV-2. Hence, we conducted an observational study on 435 healthy young adults vaccinated with two doses of BNT162b2 (Pfizer-BioNTech) vaccine to determine whether time-of-day of vaccination influences either the magnitude of humoral response or number of adverse drug reactions (ADR) being reported. We found no significant differences between morning and afternoon vaccination in terms of both titers of anti-Spike antibodies and frequency of ADR in the studied population. In addition, our analysis of data on the occurrence of ADR in 1324 subjects demonstrated that the second administration of vaccine in those with previous SARS-CoV-2 infection was associated with lower incidence of ADR. In aggregate, vaccination against COVID-19 with two doses of BNT162b2 mRNA vaccine is presumed to generate an equally efficient anti-Spike humoral response.

Determination Factors Associated with Immune Responses Towards First Dose Edmonston-Zagreb (EZ) Measles Vaccine in Indonesian Infants

Background:

Measles outbreaks under high coverage of measles vaccination in Indonesia is gaining a necessary evaluation of factors associated with measles-vaccine immune responses.

Objctive:

The purposes of recent study were to evaluate the association of sociodemographic and anthropometric parameters and specific immune responses towards first dose Edmonston-Zagreb (EZ) measles vaccine in Indonesian infants.

Methods:

A total of 35 infants were enrolled in this cohort study. Measles immune responses were followed up at one and six months after vaccination then analyzed for its association with sociodemographic, anthropometric, and nutritional parameters. The plaque-reduction microneutralization assay was conducted to measure the titer of measles specific IgG antibody. The level of CD4⁺ and CD8⁺ T-cells that exhibiting gamma interferon (IFN-γ) secretion were analyzed by flow cytometry. The association between variable was analyzed by linear regression. The difference immune response among variable were analyzed with Mann-Whitney test.

Results:

Vitamin A supplementation and breastfeeding were predicted as associated factor for humoral and cellular immune response after one month and six months measles vaccination among Indonesia Infants.

Conclusion:

Nutritional factor is associated with measles vaccination immune response in Indonesian infants.

Exploring the Immune-Boosting Functions of Vitamins and Minerals as Nutritional Food Bioactive Compounds: A Comprehensive Review

Food components have long been recognized to play a fundamental role in the growth and development of the human body, conferring protective functionalities against foreign matter that can be severe public health problems. Micronutrients such as vitamins and minerals are essential to the human body, and individuals must meet their daily requirements through dietary sources. Micronutrients act as immunomodulators and protect the host immune response, thus preventing immune evasion by pathogenic organisms. Several experimental investigations have been undertaken to appraise the immunomodulatory functions of vitamins and minerals. Based on these experimental findings, this review describes the immune-boosting functionalities of micronutrients and the mechanisms of action through which these functions are mediated. Deficiencies of vitamins and minerals in plasma concentrations can lead to a reduction in the performance of the immune system functioning, representing a key contributor to unfavorable immunological states. This review provides a descriptive overview of the characteristics of the immune system and the utilization of micronutrients (vitamins and minerals) in preventative strategies designed to reduce morbidity and mortality among patients suffering from immune invasions or autoimmune disorders.

Implications of Vitamins in COVID-19 Prevention and Treatment through Immunomodulatory and Anti-Oxidative Mechanisms

Since the appearance of the coronavirus disease 2019 (COVID-19) and its announcement as a global pandemic, the search for prophylactic and therapeutic options have become a priority for governments and the scientific community. The approval of several vaccines against SARS-CoV-2 is being crucial to overcome this situation, although the victory will not be achieved while the whole population worldwide is not protected against the virus. This is why alternatives should be studied in order to successfully support the immune system before and during a possible infection. An optimal inflammatory and oxidative stress status depends on an adequate diet. Poor levels of several nutrients could be related to an impaired immune response and, therefore, an increased susceptibility to infection and serious outcomes. Vitamins exert a number of anti-microbial, immunomodulatory, anti-inflammatory, and antioxidant activities, which can be of use to fight against this and several other diseases (especially vitamin D and C). Even though they cannot be considered as a definitive therapeutic option, in part owing to the lack of solid conclusions from well-designed clinical trials, currently available evidence from similar respiratory diseases may indicate that it would be rational to deeply explore the use of vitamins during this global pandemic.

Interplay of Nutrition and Psychoneuroendocrineimmune Modulation: Relevance for COVID-19 in BRICS Nations

The consequences of COVID-19 are not limited to physical health deterioration; the impact on neuropsychological well-being is also substantially reported. The inter-regulation of physical health and psychological well-being through the psychoneuroendocrineimmune (PNEI) axis has enduring consequences in susceptibility, treatment outcome as well as recuperation. The pandemic effects are upsetting the lifestyle, social interaction, and financial security; and also pose a threat through perceived fear. These consequences of COVID-19 also influence the PNEI system and wreck the prognosis. The nutritional status of individuals is also reported to have a determinative role in COVID-19 severity and convalescence. In addition to energetic demand, diet also provides precursor substances [amino acids (AAs), vitamins, etc.] for regulators of the PNEI axis such as neurotransmitters (NTs) and immunomodulators. Moreover, exaggerated immune response and recovery phase of COVID-19 demand additional nutrient intake; widening the gap of pre-existing undernourishment. Mushrooms, fresh fruits and vegetables, herbs and spices, and legumes are few of such readily available food ingredients which are rich in protein and also have medicinal benefits. BRICS nations have their influences on global development and are highly impacted by a large number of confirmed COVID-19 cases and deaths. The adequacy and access to healthcare are also low in BRICS nations as compared to the rest of the world. Attempt to combat the COVID-19 pandemic are praiseworthy in BRICS nations. However, large population sizes, high prevalence of undernourishment (PoU), and high incidence of mental health ailments in BRICS nations provide a suitable landscape for jeopardy of COVID-19. Therefore, appraising the interplay of nutrition and PNEI modulation especially in BRICS countries will provide better understanding; and will aid in combat COVID-19. It can be suggested that the monitoring will assist in designing adjunctive interventions through medical nutrition therapy and psychopsychiatric management.

Might Routine Vitamin A Monitoring in Cystic Fibrosis Patients Reduce Virus-Mediated Lung Pathology?

Cystic fibrosis (CF) is an autosomal recessive gene disorder that affects tens of thousands of patients worldwide. Individuals with CF often succumb to progressive lung disease and respiratory failure following recurrent infections with bacteria. Viral infections can also damage the lungs and heighten the CF patient's susceptibility to bacterial infections and long-term sequelae. Vitamin A is a key nutrient important for immune health and epithelial cell integrity, but there is currently no consensus as to whether vitamin A should be monitored in CF patients. Here we evaluate previous literature and present results from a CF mouse model, showing that oral vitamin A supplements significantly reduce lung lesions that would otherwise persist for 5-6 weeks post-virus exposure. Based on these results, we encourage continued research and suggest that programs for the routine monitoring and regulation of vitamin A levels may help reduce virus-induced lung pathology in CF patients.

Effect of HIV status and retinol on immunogenicity to oral cholera vaccine in adult population living in an endemic area of Lukanga Swamps, Zambia

Background

We set out to assess the impact of human immunodeficiency virus (HIV) and micronutrient deficiency as indicated by serum retinol levels on the immune responses to Oral Cholera Vaccine (Shanchol™) in a cohort of participants in Lukanga Swamps, Zambia. Cholera remains endemic in Zambia with vaccines being the only effective preventive measures. However, the effect of these vaccines on populations living with HIV has not been widely documented.

Methods

HIV testing and confirmation was done using the Alere Determine™ HIV-1/2 and Uni-Gold™ kits while vibriocidal antibody assay was applied for vaccine immunogenicity. Serum retinol analysis was assessed by Shimadzu Prominence HCT-2010 High Performance Liquid Chromatography (HPLC). The primary outcome was log transformed geometric mean titre.

Results

From 47 participants screened for HIV, 51% (24) tested positive. There was a statistically significant reduction in Ogawa geometric mean ratio (GMR) by 67% (GMR = 0.33; 95% CI: -0.15, 0.76; p-value = 0.009) attributable to HIV positivity with a non-significant reduction in Inaba GMR by about 50% due to HIV positivity. When doubling of retinol levels modelled, GMR reduction against Ogawa were non-significant but that against Inaba resulted in a significant reduction in geometric mean titer (GMT) (GMT-0.33, C.I 0.16–0.66, p-value 0.002). At 1000copies/ml viral load cut off and 350 cells/μl CD4 counts, Ogawa GMT was two times higher 11.16 (95%CI: 8.20–15.19) versus 6.06 (95%CI: 4.04–9.10) in low viremia participants, and three times higher in above threshold CD4 count participants; 24.81 (95%CI: 18.94–32.50) versus 7.07 (95%CI: 5.22–9.58).

Conclusion

Our results show that while Shanchol™ is immunogenic in both HIV+/- individuals, HIV + participants responded poorly. Viral load and CD4 count affected vaccine immunogenicity. More research is required for detailed understanding of this in order to appropriately inform policy and practice.

Is Vitamin A Supplementation Associated With Anemia in Children Under 5 Years of Age in Peru: Secondary Analysis of the "Demographic Health Survey" 2015-2018?

Vitamin A deficiency (VAD) affects 12% of Peruvians under 5 years of age. Recent studies have shown an association with hematopoiesis and iron metabolism. In Peru, 3-quarters of a million children have anemia. We aimed to identify an association between Vitamin A supplementation (VAS) and anemia in children under 5 years of age. A cross-sectional secondary analytical study from the Peruvian Demographic Survey and Family Health (DHS) was conducted. The primary outcome, anemia, was measured through hemoglobin concentration and adjusted by altitude. The DHS interviewer ensured the participant's VAS in the last 6 months through a structural healthcare card. The association was statistically significant using crude regression but disappeared when adjusted per socioeconomic level and gender. VAS was not significantly associated with a lower prevalence of anemia. Further studies are required to help identify the association between VAS and anemia.

Immunostimulant and Antidepressant Effect of Natural Compounds in the Management of Covid-19 Symptoms

In recent years, the use of natural compounds as adjuvant treatments and alternatives to traditional pharmacological therapies has become increasingly popular. These compounds have a wide range of biological effects, such as: antioxidant, anti-aging, hypocholesterolizing, hypoglycemic, antitumoral, antidepressant, anxiolytic activity, etc. Almost all of these compounds are easily available and are contained in different foods. At the end of 2019 the Coronavirus SARS-CoV-2 appeared in China and quickly spread throughout the world, causing a pandemic. The most common symptoms of this infection are dry cough, fever, dyspnea, and in severe cases bilateral interstitial pneumonia, with consequences that can lead to death. The nations, in trying to prevent the spread of infection, have imposed social distancing and lockdown measures on their citizens. This had a strong psychological-social impact, leading to phobic, anxious and depressive states. Pharmacological therapy could be accompanied by treatment with several natural compounds, such as vitamins, baicalein, zinc and essential oils. These compounds possess marked immunostimulant activity, strengthening the immune response and mitigating interactions between the virus and the host cell. They also have an antidepressant effect, acting on certain neurotransmitters.

Serum amyloid A delivers retinol to intestinal myeloid cells to promote adaptive immunity

[Figure: see text].

Sendai Virus-Vectored Vaccines That Express Envelope Glycoproteins of Respiratory Viruses

Human respiratory syncytial virus (HRSV), human metapneumovirus (HMPV), and human parainfluenza viruses (HPIVs) are leading causes of respiratory disease in young children, the elderly, and individuals of all ages with immunosuppression. Vaccination strategies against these pneumoviruses and paramyxoviruses are vast in number, yet no licensed vaccines are available. Here, we review development of Sendai virus (SeV), a versatile pediatric vaccine that can (a) serve as a Jennerian vaccine against HPIV1, (b) serve as a recombinant vaccine against HRSV, HPIV2, HPIV3, and HMPV, (c) accommodate foreign genes for viral glycoproteins in multiple intergenic positions, (d) induce durable, mucosal, B-cell, and T-cell immune responses without enhanced immunopathology, (e) protect cotton rats, African green monkeys, and chimpanzees from infection, and (f) be formulated into a vaccine cocktail. Clinical phase I safety trials of SeV have been completed in adults and 3–6-year-old children. Clinical testing of SeVRSV, an HRSV fusion (F) glycoprotein gene recombinant, has also been completed in adults. Positive results from these studies, and collaborative efforts with the National Institutes of Health and the Serum Institute of India assist advanced development of SeV-based vaccines. Prospects are now good for vaccine successes in infants and consequent protection against serious viral disease.

Dietary Intervention Impacts Immune Cell Functions and Dynamics by Inducing Metabolic Rewiring

Accumulating evidence has shown that nutrient metabolism is closely associated with the differentiation and functions of various immune cells. Cellular metabolism, including aerobic glycolysis, fatty acid oxidation, and oxidative phosphorylation, plays a key role in germinal center (GC) reaction, B-cell trafficking, and T-cell-fate decision. Furthermore, a quiescent metabolic status consolidates T-cell-dependent immunological memory. Therefore, dietary interventions such as calorie restriction, time-restricted feeding, and fasting potentially manipulate immune cell functions. For instance, intermittent fasting prevents the development of experimental autoimmune encephalomyelitis. Meanwhile, the fasting response diminishes the lymphocyte pool in gut-associated lymphoid tissue to minimize energy expenditure, leading to the attenuation of Immunoglobulin A (IgA) response. The nutritional status also influences the dynamics of several immune cell subsets. Here, we describe the current understanding of the significance of immunometabolism in the differentiation and functionality of lymphocytes and macrophages. The underlying molecular mechanisms also are discussed. These experimental observations could offer new therapeutic strategies for immunological disorders like autoimmunity.

Multiple Vaccinations and the Enigma of Vaccine Injury

A growing number of vaccines are administered at the same time or in close succession, increasing the complexity of assessing vaccine safety. Individual vaccines are assumed to have no other effect than protection against the targeted pathogen, but vaccines also have nonspecific and interactive effects, the outcomes of which can be beneficial or harmful. To date, no controlled trials and very few observational studies have determined the impact of vaccination schedules on overall health. The balance of the risks and benefits from mass vaccination therefore remains uncertain. Recent studies worryingly suggest links between multiple vaccinations and increased risks of diverse multisystem health problems, including allergies, infections, and neuropsychiatric or neurodevelopmental disorders. Here, we propose that, in susceptible persons, multiple vaccinations activate the retinoid cascade and trigger apoptotic hepatitis, leading to cholestatic liver dysfunction, in which stored vitamin A compounds (retinyl esters and retinoic acid) enter the circulation in toxic concentrations; this induces endogenous forms of hypervitaminosis A, with the severity of adverse outcomes being directly proportional to the concentration of circulating retinoids. In very low concentrations, vitamin A and its major metabolite retinoic acid contribute to immune function and to the process of immunization, whereas excess vitamin A increases the risk of adverse events, including common "side-effects" as well as chronic adverse outcomes. The increasing rates of allergy, ear infections, and neurodevelopmental disorders (NDDs) in countries with high rates of vaccination could be related to mass vaccination and to its impact on liver function and vitamin A metabolism, collectively representing endogenous manifestations of hypervitaminosis A. Further studies of health outcomes in vaccinated and unvaccinated groups are urgently needed, to increase understanding of the pathophysiology and treatment of vaccine injury, to identify the risk factors and screen for vaccine injury, to inform public health policy on potential hazards related to vaccination schedules, and to optimize the safety and benefits of vaccines.

Nuclear Receptors, Ligands and the Mammalian B Cell

Questions concerning the influences of nuclear receptors and their ligands on mammalian B cells are vast in number. Here, we briefly review the effects of nuclear receptor ligands, including estrogen and vitamins, on immunoglobulin production and protection from infectious diseases. We describe nuclear receptor interactions with the B cell genome and the potential mechanisms of gene regulation. Attention to the nuclear receptor/ligand regulation of B cell function may help optimize B cell responses, improve pathogen clearance, and prevent damaging responses toward inert- and self-antigens.

Regulation of the germinal center response by nuclear receptors and implications for autoimmune diseases

The immune system plays an essential role in protecting the host from infectious diseases and cancer. Notably, B and T lymphocytes from the adaptive arm of the immune system can co-operate to form long-lived antibody responses and are therefore the main target in vaccination approaches. Nevertheless, protective immune responses must be tightly regulated to avoid hyper-responsiveness and responses against self that can result in autoimmunity. Nuclear receptors (NRs) are perfectly adapted to rapidly alter transcriptional cellular responses to altered environmental settings. Their functional role is associated with both immune deficiencies and autoimmunity. Despite extensive linking of nuclear receptor function with specific CD4 T helper subsets, research on the functional roles and mechanisms of specific NRs in CD4 follicular T helper cells (Tfh) and germinal center (GC) B cells during the germinal center reaction is just emerging. We review recent advances in our understanding of NR regulation in specific cell types of the GC response and discuss their implications for autoimmune diseases such as systemic lupus erythematosus (SLE).

Strengthening the Immune System and Reducing Inflammation and Oxidative Stress through Diet and Nutrition: Considerations during the COVID-19 Crisis

The coronavirus-disease 2019 (COVID-19) was announced as a global pandemic by the World Health Organization. Challenges arise concerning how to optimally support the immune system in the general population, especially under self-confinement. An optimal immune response depends on an adequate diet and nutrition in order to keep infection at bay. For example, sufficient protein intake is crucial for optimal antibody production. Low micronutrient status, such as of vitamin A or zinc, has been associated with increased infection risk. Frequently, poor nutrient status is associated with inflammation and oxidative stress, which in turn can impact the immune system. Dietary constituents with especially high anti-inflammatory and antioxidant capacity include vitamin C, vitamin E, and phytochemicals such as carotenoids and polyphenols. Several of these can interact with transcription factors such as NF-kB and Nrf-2, related to anti-inflammatory and antioxidant effects, respectively. Vitamin D in particular may perturb viral cellular infection via interacting with cell entry receptors (angiotensin converting enzyme 2), ACE2. Dietary fiber, fermented by the gut microbiota into short-chain fatty acids, has also been shown to produce anti-inflammatory effects. In this review, we highlight the importance of an optimal status of relevant nutrients to effectively reduce inflammation and oxidative stress, thereby strengthening the immune system during the COVID-19 crisis.

The role of β-carotene and vitamin A in atherogenesis: Evidences from preclinical and clinical studies

Atherosclerotic cardiovascular disease (ASCVD) is the principal contributor to myocardial infarction, the leading cause of death worldwide. Epidemiological and mechanistic studies indicate that β-carotene and its vitamin A derivatives stimulate lipid catabolism in several tissues to reduce the incidence of obesity, but their roles within ASCVD are elusive. Herein, we review the mechanisms by which β-carotene and vitamin A modulate ASCVD. First, we summarize the current knowledge linking these nutrients with epidemiological studies and lipoprotein metabolism as one of the initiating factors of ASCVD. Next, we focus on different aspects of vitamin A metabolism in immune cells such as the mechanisms of carotenoid uptake and conversion to the vitamin A metabolite, retinoic acid. Lastly, we review the effects of retinoic acid on immuno-metabolism, differentiation, and function of macrophages and T cells, the two pillars of the innate and adaptive immune response in ASCVD, respectively. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.