Does smoking have an impact on the immunological response to COVID-19 vaccines? Evidence from the VASCO study and need for further studies

Lifestyle and Biochemical Parameters That May Hamper Immune Responses in Pediatric Patients After Immunization with the BNT162b2 mRNA COVID-19 Vaccine

BACKGROUND

The aim of this study was to evaluate whether increased body mass index (BMI) and biochemical and lifestyle parameters linked to obesity and smoke exposure disrupt immune responses of children and adolescents following vaccination with the mRNA BNT162b2 vaccine.

METHODS

A prospective, single-center, cohort study was conducted. Participants were assigned to receive two doses of the mRNA vaccine. Anti-SARS-CoV-2 IgG and neutralizing antibodies (AB) were measured before vaccination (T0) and 14 days after the second dose (T1). BMI and biochemical parameters were evaluated at T0. A questionnaire on lifestyle characteristics was filled in.

RESULTS

IgG optical density (OD) ratio at T1 was lower in the overweight-obese group regardless of COVID-19 disease positive history [p = 0.028 for the seronegative group, p = 0.032 for the seropositive group]. Neutralizing AB were lower in overweight-obese participants in the seronegative group at T1 [p = 0.008]. HDL, fasting glucose/insulin ratio (FGIR), C-reactive protein (CRP), HBA1c, uric acid, and smoke exposure were significantly correlated with BMI [p = 0.006, p < 0.001, p < 0.001, p = 0.006, p = 0.009, p < 0.001, respectively]. The main biochemical parameters that were inversely correlated with IgG and neutralizing AB titers at T1 were uric acid [p = 0.018, p = 0.002], FGIR [p = 0.001, p = 0.008] and HBA1C [p = 0.027, p = 0.038], while smoke exposure negatively affected the humoral immune responses at T0 in the convalescent group [p = 0.004, p = 0.005].

CONCLUSIONS

Current data suggests that uric acid, insulin resistance (IR), and smoke exposure could adversely affect the immune responses in overweight-obese vaccinated children, highlighting the need for actions to enhance the protection of this particular subgroup.

Examination of diet quality and alcohol on serum IgG levels after first and second COVID-19 vaccines

RATIONALE

The change of IgG of COVID-19 vaccine was thought to be an effect of diet quality or daily habits.

AIMS AND OBJECTIVES

This study aimed to correlate diet quality and healthy living factors with serum IgG response in the blood.

METHODS

Participants were selected from volunteers who had their first vaccination and did not have COVID-19 disease (Male = 21 Female = 40). Serum IgG levels were measured on average (avg) 28 days after the COVID-19 vaccine. Information was obtained directly from the participants by questionnaire method (Food consumption record, frequency of food consumption, Diet Quality Index [(DQI], etc.).

RESULTS

A significant difference was observed in the IgG levels of the second measurement of age (young/middle) and gender (male/female) (p < 0.05). A significant difference was found in the first measurement of serum IgG levels and IgG avgs of those with medium diet quality and those who did not drink alcohol (p < 0.05). When the IgG2/1 ratio was examined between alcohol users and nonalcohol, a significant increase was observed about two times in non-alcohol users (p = 0.039). There is a positive significant moderate strength relationship between the second measurements of IgG and anthropometric measurements and the first, second, and avg measurements of IgG with DQI. It was found that there was a negative significant medium-strength relationship between individuals' amount of alcohol consumption and IgG avg (r = -0.535, p = 0.009).

CONCLUSIONS

Medium diet quality has been seen to affect antibody levels positively. At the same time, it is thought that alcohol use negatively affects serum IgG antibody response in the long term. Other than that, there was shown to be a correlation between IgG levels and DQI.

Does Tobacco Smoking Affect Vaccine-Induced Immune Response? A Systematic Review and Meta-Analysis

Background. Causing approximately 8 million deaths each year, tobacco smoking represents a significant public health concern. Evidence shows that smoking significantly impairs antibody production and immune cell activity following vaccination. Objectives. This review aims to provide a comprehensive overview of the literature regarding how smoking reduces the effectiveness of active immunization by affecting vaccine-induced immune response. Methods. This study was performed according to the PRISMA guidelines, and the protocol was registered on the PROSPERO platform (ID: CRD42024582638). PubMed, Scopus and Web of Science were consulted as bibliographic and citation databases. Studies published in Italian and English and that aimed to investigate the effects of exposure to active and passive tobacco smoking on vaccine-induced immune response were included. Results. Thirty-four studies were selected. Overall, a decrease in antibody levels and avidity and in immune cell production were observed in individuals exposed to smoke. The meta-analysis showed a weighted mean difference between smokers and non-smokers equal to 0.65 (95% CI: 0.10-1.19, p = 0.02) for vaccinations against COVID-19, influenza, pneumococcus, HBV, HPV, tetanus, pertussis, polio, haemophilus influenzae type b, measles-mumps-rubella, and recurrent urinary tract infections. Conclusions. Smoking cessation campaigns should be considered in order to increase the effectiveness of vaccination programs. Furthermore, the opportunity to adopt different vaccine dosing schemes for smokers and non-smokers, especially in acute epidemics, should be considered.

How does geographical diversity shape vaccine efficacy?

Vaccination is a cornerstone of public health, saving millions of lives each year by preventing a variety of infectious diseases. Yet, despite global vaccination efforts, emerging research highlights significant geographical disparities in vaccine efficacy and immunogenicity. These variations underscore the critical interplay between immunological factors and environmental, genetic, and nutritional elements across different populations. Our review article aimed to explore the multifactorial reasons behind geographical variations in vaccine efficacy. Also, this study has shown how important host factors like age, obesity, gender, and genetic diversity, especially within the major histocompatibility complex, are in determining how well a vaccine works. Nutritional status, namely deficiencies in micronutrients such as vitamins and zinc, and lifestyle factors including stress, sleep, alcohol consumption, and physical activity are also shown to have profound effects on vaccine-induced immunity. Importantly, our paper also brought to light the influence of microbial and ecological factors, such as the gut microbiome and environmental pollutants, on the immune system's response to vaccination. The findings emphasize the importance of tailoring vaccination strategies to accommodate the unique immunological landscapes shaped by geographical and societal factors. This tailored approach could enhance vaccine efficacy, reduce disparities in vaccine response, and ultimately contribute to the global fight against infectious diseases.

Heterologous and homologous COVID-19 mRNA vaccination schemes for induction of basic immunity show similar immunogenicity regarding long-term spike-specific cellular immunity in healthcare workers

Healthcare workers (HCWs) are recommended to receive at least three spike-antigen exposures to generate basic immunity and to mediate herd protection of vulnerable patients. So far, less attention has been put on the cellular immune response induced by homologous (three BTN162b2mRNA doses) or heterologous (mRNA-1273 as third dose building on two BTN162bmRNA doses) and the immunological impact of breakthrough infections (BTIs). Therefore, in 356 vaccinated HCWs with or without BTIs the Anti-SARS-CoV-2-Spike-IgG concentrations and avidities and B- and T-cell-reactivity against SARS-CoV-2-Spike-S1- and Nucleocapsid-antigens were assessed with Interferon-gamma-ELISpot and by flow-cytometry. HCWs who had hybrid immunity due to BTIs exhibited strong T-cell-reactivity against the Spike-S1-antigen. A lasso regression model revealed a significant reduction in T-cell immune responses among smokers (p < 0.0001), with less significant impact observed for age, sex, heterologous vaccination, body-mass-index, Anti-Nucleocapsid T-cell reactivity, days since last COVID-19-immunization, and Anti-SARS-CoV-2-Spike-IgG. Although subgroup analysis revealed higher Anti-SARS-CoV-2-Spike-IgG after heterologous vaccination, similar cellular reactivity and percentages of Spike-reactive T- and B-cells were found between homologous and heterologous vaccination. Anti-SARS-CoV-2-Spike-IgG concentrations and avidity significantly correlated with activated T-cells. CD4 + and CD8 + responses correlated with each other. A strong long-term cellular immune response should be considered as baseline for recommendations of booster doses in HCWs with prioritization of smokers. HCWs presented significant T-cellular reactivity towards Spike-S1-antigen with particularly strong responses in hybrid immunized HCWs who had BTIs. HCWs without BTI presented similar percentages of Spike-specific B- and T-cells between homologous or heterologous vaccination indicating similar immunogenicity for both mRNA vaccines, BNT162b2mRNA and mRNA-1273.

Occult Serologically Confirmed Cases of SARS-CoV-2 Coronavirus among the General Population in the Era of the Fourth Vaccination

Background: Asymptomatic SARS-CoV-2 infection can significantly increase the spread of the COVID-19 pandemic. We aimed to investigate the epidemiological and clinical predictors of occult serologically confirmed SARS-CoV-2 cases among the general population during the fourth vaccination era in Israel. Methods: We conducted a cross-sectional study among individuals aged ≥18 years who had not been tested for COVID-19 in the preceding 5 months. Occult serologically confirmed cases were based on the presence of anti-N IgG antibodies. Potential risk factors were examined. Multivariable regression analysis identified independent predictors of subclinical SARS-CoV-2 infection. Results: This study included 504 participants. The prevalence of occult serologically confirmed SARS-CoV-2 was 12.5%. Chronic disease was found to be an independent predictor for the absence of occult disease (aOR) 0.4 [95% (CI): 0.18-0.87], p-value = 0.02). No significant differences were observed in age, sex, marital status, number of children, vaccination status, or exposure to COVID-19 infection between participants with and without SARS-CoV-2 sub-infection. Conclusions: We found a lower prevalence of occult serologically confirmed SARS-CoV-2 cases, compared to previous reports, and a negative correlation between chronic disease and occult SARS-CoV-2. Continued research, surveillance, and intervention strategies are needed to optimize long-term health outcomes and provide valuable insights for public health policymakers and clinicians.

The Protection Level of S-RBD SARS-CoV-2 Immunoglobulin G Antibodies Using the Chemiluminescent Immunoassay Compared to the Surrogate Virus Neutralization Test Method

COVID-19 infection in high-risk populations is fatal and has a poor prognosis, necessitating a test to determine the protectiveness of immune response. Antibody testing is necessary to determine the body's immune response to COVID-19 infection and also vaccination strategies. Among the various methods available, the chemiluminescent immunoassay (CLIA) test is more widely used and accessible to determine antibody levels. This study aimed to determine the protection level of S-RBD SARS-CoV-2 IgG using CLIA compared to the Surrogate Virus Neutralization Test (SVNT). The population of this study comprised all healthcare professionals who experienced S-RBD SARS-CoV-2 IgG antibody level examinations. S-RBD SARS-CoV-2 IgG antibody levels were examined using CLIA and SVNT. The cut-off was determined using a receiver operating characteristic (ROC) curve, and area under the curve (AUC) measurements were evaluated. The result showed a strong positive correlation between S-RBD SARS-CoV-2 IgG CLIA and SVNT, with a value of r = 0.933 and p < 0.001. The value ≥ 37.29 BAU/mL was determined as the cut-off based on SVNT 30% inhibition level with sensitivity, specificity, and positive and negative predictive values of 96.5%, 90.9%, 96.5%, and 90.9%, respectively. A titer of antibodies greater than or equal to 37.29 BAU/mL with CLIA showed the presence of protective antibodies compared to SVNT.

Reported COVID-19 vaccines side effects among Algerian athletes: a comparison between inactivated virus, adenoviral vector, and mRNA COVID-19 vaccines

OBJECTIVES

Many types of COVID19 vaccines are administered globally, yet there is not much evidence regarding their side effects among athletes. This study evaluated the selfreported postvaccination side effects of inactivated virus, adenoviral vector, and mRNA COVID19 vaccines among Algerian athletes.

METHODS

A cross-sectional survey-based study was carried out in Algeria between March 01 and 4 April 2022. The study used a validated questionnaire with twenty-five multiple-choice items covering the participants' anamnestic characteristics, post-vaccination side effects (their onset and duration), post-vaccination medical care, and risk factors.

RESULTS

A total of 273 athletes completed the survey. Overall, (54.6%) of the athletes reported at least one local side effect, while (46.9%) reported at least one systemic side effect. These side effects were more prevalent among the adenoviral vector group compared to the inactivated virus and mRNA groups. The most common local side effect was injection site pain (29.9%), while Fever (30.8%) was the most prevalent systemic side effect. The age group of 31-40 years, allergy, previous infection with COVID-19, and the first dose of vaccines were associated with an increased risk of side effects for all groups of COVID-19 vaccines. Logistic regression analysis further revealed that compared to males, the incidence of reported side effects was significantly higher in females (odd ratio (OR) = 1.16; P = 0.015*) only for the adenoviral vector vaccine group. In addition, a significantly higher percentage of athletes group of high dynamic/moderate static or high dynamic /high static components suffered from post-vaccination side effects compared to the group of athletes with high dynamic/low static components (OR = 14.68 and 14.71; P < 0.001, respectively).

CONCLUSIONS

The adenoviral vector vaccines have the highest rate of side effects, followed by the inactivated virus and mRNA COVID-19 vaccines. COVID‑19 vaccines were well-tolerated among Algerian athletes and there were no reports of serious side effects. Nevertheless, further long-term follow-up study with a larger sample size of athletes (from different types and sports categories) is warranted to establish the long-term safety of the COVID-19 vaccine.

Vaccinomics and adversomics: key elements for a personalized vaccinology

Vaccines are one of the most important and effective tools in the prevention of infectious diseases and research about all the aspects of vaccinology are essential to increase the number of available vaccines more and more safe and effective. Despite the unquestionable value of vaccinations, vaccine hesitancy has spread worldwide compromising the success of vaccinations. Currently, the main purpose of vaccination campaigns is the immunization of whole populations with the same vaccine formulations and schedules for all individuals. A personalized vaccinology approach could improve modern vaccinology counteracting vaccine hesitancy and giving great benefits for human health. This ambitious purpose would be possible by facing and deepening the areas of vaccinomics and adversomics, two innovative areas of study investigating the role of a series of variables able to influence the immune response to vaccinations and the development of serious side effects, respectively. We reviewed the recent scientific knowledge about these innovative sciences focusing on genetic and non-genetic basis involved in the individual response to vaccines in terms of both immune response and side effects.

Patients with Hashimoto's thyroiditis present higher immune response to COVID-19 mRNA vaccine compared to normal individuals

AIM

To evaluate the response (titers of anti-COVID-19 antibodies) to COVID-19 mRNA vaccine of patients with Hashimoto's thyroiditis and normal individuals.

PATIENTS AND METHODS

Twenty-four patients with Hashimoto's thyroiditis and 51 normal individuals were studied after the third dose of the vaccine.

RESULTS

Patients with Hashimoto's thyroiditis showed significantly higher immune response after the third dose of the COVID-19 mRNA vaccine compared with normal individuals (p = 0.020). After elimination of the four smokers with Hashimoto's thyroiditis, the immune response between the remaining 20 non-smoking patients compared with the response of the 23 non-smoking normal individuals was not different (p = 0.564). There was a significant positive correlation of the anti-COVID-19 antibodies with BMI (p = 0.029) but not with waist circumference in the patients with Hashimoto's thyroiditis (p = 0.054). Similar correlations were not found in normal individuals. Waist circumference could be considered as representative of visceral adipose tissue. In obese normal individuals (BMI ≥ 30), anti-COVID-19 antibodies were not different from those in lean normal individuals (BMI < 25). In obese patients with Hashimoto's thyroiditis, anti-COVID-19 antibodies were significantly higher compared to those in lean patients (p = 0.013). Median anti-COVID-19 antibody titer in obese patients with Hashimoto's thyroiditis was also significantly higher compared to that in obese normal individuals (p = 0.009).

CONCLUSIONS

Patients with Hashimoto's thyroiditis show significantly higher immune response after the third dose of the COVID-19 mRNA vaccine compared with normal individuals. Obese patients with Hashimoto's thyroiditis show additionally a significantly higher immune response compared with lean patients.

Evaluation of SARS-CoV-2 Antibody Levels in Pharmacists and Pharmacy Staff Following CoronaVac Vaccination

Objectives

The aim of this study was to determine the seropositivity rate of pharmacists and pharmacy staff after the administration of two doses of the CoronaVac-SinoVac vaccine and to assess changes in their antibody levels according to sociodemographic characteristics.

Materials and Methods

This descriptive study was conducted between June 04, 2021 and September 30, 2021 in pharmacies located in Istanbul, Türkiye. The results of self-initiated immunoglobulin (Ig) G testing of the pharmacists and pharmacy staff, conducted at diagnostic laboratories contracted by the Istanbul Chamber of Pharmacists, were obtained using an online data collection tool. IgG measurements taken from 15 days up to 120 days after the two vaccine doses were included in the study. Participants were asked whether they smoked, had any chronic diseases (hypertension, chronic obstructive pulmonary disease, asthma, diabetes, etc.), or took any medications. Subgroup analyses were performed for each method used to measure antibody levels.

Results

The study included 329 pharmacists/pharmacy staff (298 pharmacists and 31 pharmacy staff). The mean age of the participants was 49.7 ± 13.7 years, and 71.4% were female. The antibody positivity of the 329 participants was 94.9% following the two doses. The positivity rate was 95.4% in participants under 65 years of age, whereas it was 91.8% in those aged 65 years and over. There was no significant difference in the mean age between those with positive and negative antibody results (p > 0.05). Although antibody levels were lower older people, smokers, and those with chronic diseases, this difference was not statistically significant (p > 0.05).

Conclusion

Seropositivity developed following the administration of two doses of CoronaVac-Sinovac vaccines. IgG antibody levels were lower in older adults, smokers, and those with chronic diseases, although not to a statistically significant extent. Further studies are needed to better understand the reasons for the different immunological responses to COVID-19.

Long-term course of neutralising antibodies against SARS-CoV-2 in vaccinated and unvaccinated staff and residents in a Swiss nursing home: a cohort study 2021-2022

BACKGROUND

Given their high-risk resident population, nursing homes were critical institutions in the COVID-19 pandemic, calling for continued monitoring and vaccine administration to healthcare workers and residents. Here, we studied long-term severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunity in vaccinated and unvaccinated healthcare workers and residents of a nursing home in Switzerland between February 2021 and June 2022.

METHODS

Our study comprised 45 participants, of which 39 were healthcare workers and six were residents. All participants were offered a maximum of three mRNA vaccine doses (Pfizer/BioNTech, BNT162b2) in December 2020, January 2021, and November/December 2021. Thirty-five participants received three vaccinations, seven either one or two, and three remained unvaccinated. We collected four blood samples: one in March 2021 and three during follow-ups in November 2021, February 2022, and June 2022. We performed a multifactorial serological SARS-CoV-2 assay (ABCORA) for immunoglobulin G, A, and M responses to spike (receptor-binding domain, S1, and S2) and nucleocapsid (N) proteins. Furthermore, we assessed predicted neutralisation activity based on signal over cutoff in ABCORA. We collected epidemiological data from participants via a standardised questionnaire.

RESULTS

Thirty-two (71%) of the 45 participants showed hybrid immunity from combined vaccination and previous infection; 10 (22%) had only vaccine-induced immunity; and three (7%) had only post-infection immunity. Participants with hybrid immunity showed the highest predicted neutralisation activity at the end of the study period (median Sum S1 = 273), and unvaccinated participants showed the lowest (median Sum S1 = 41). Amongst participants who reported a SARS-CoV-2 infection, median Sum S1 levels increased with the number of vaccinations (p = 0.077). The healthcare worker group showed a significant time-dependent decrease in median Sum S1 after base immunisation (93% decrease, p = 0.0005) and the booster dose (26% decrease, p = 0.010). Predicted neutralisation activity was lower amongst residents (adjusted ratio of means [AM] = 0.7, 95% confidence interval [CI] = 0.3-1.0) and amongst smokers (AM = 0.5, 95% CI 0.3-0.8). Activity increased with the number of vaccinations (booster: AM = 3.6, 95% CI 1.5-8.8; no booster: AM = 2.3, 95% CI 0.9-2.5). Positive SARS-CoV-2 infection status tended to confer higher predicted neutralisation levels (AM = 1.5, 95% CI 0.9-2.5).

CONCLUSIONS

Our study of the long-term serological course of SARS-CoV-2 in a nursing home showed that the first SARS-CoV-2 booster vaccine was essential for maintaining antiviral antibody levels. Hybrid immunity sustained SARS-CoV-2 immunity at the highest level. In critical settings such as nursing homes, monitoring the SARS-CoV-2 immune status may guide booster vaccinations.

Genome-wide association studies of response and side effects to the BNT162b2 vaccine in Italian healthcare workers: Increased antibody levels and side effects in carriers of the HLA-A*03:01 allele

The remarkable variability of response to vaccines against SARS-CoV-2 is apparent. The present study aims to estimate the extent to which the host genetic background contributes to this variability in terms of immune response and side effects following the administration of the BNT162b2 vaccine. We carried out a genome wide association study (GWAS) by genotyping 873 Italian healthcare workers who underwent anti-SARS-CoV-2 vaccination with the BNT162b2 vaccine and for whom information about anti-SARS-CoV-2 spike antibodies titers and vaccine side effects were available. The GWAS revealed a significant association between the HLA locus and the anti-SARS-CoV-2 Spike antibodies level at 2 months following the first dose of vaccine (SNP: rs1737060; p = 9.80 × 10-11 ). In particular, we observed a positive association between the antibody levels and the presence of the HLA-A*03:01 allele. The same allele was found associated with a 2-2.4-fold increased risk of experiencing specific side effects such as fever, chills and myalgia and a 1.5-1.8-fold increased risk of joint pain, nausea, fatigue, headache and asthenia, independently of age and sex. This study confirms that the heterogeneity in the immune response to the BNT162b2 vaccine and in its side effects are at least partially influenced by genetic variants. This information, integrated with individual biological and lifestyle-related correlates, could be of use in the definition of algorithms aimed at the identification of subjects in which the administration of additional vaccine doses would be particularly beneficial to maintain immunity against the virus.

Do alternative tobacco products induce less adverse respiratory risk than cigarettes?

RATIONALE

Due to the relatively short existence of alternative tobacco products, gaps exist in our current understanding of their long-term respiratory health effects. We therefore undertook the first-ever side-by-side comparison of the impact of chronic inhalation of aerosols emitted from electronic cigarettes (EC) and heated tobacco products (HTP), and combustible cigarettes (CC) smoke.

OBJECTIVES

To evaluate the potential differential effects of alternative tobacco products on lung inflammatory responses and efficacy of vaccination in comparison to CC.

METHODS

Mice were exposed to emissions from EC, HTP, CC, or air for 8 weeks. BAL and lung tissue were analyzed for markers of inflammation, lung damage, and oxidative stress. Another group was exposed for 12 weeks and vaccinated and challenged with a bacterial respiratory infection. Antibody titers in BAL and sera and pulmonary bacterial clearance were assessed.

MAIN RESULTS

EC- and HTP-aerosols significantly augmented lung immune cell infiltrates equivalent to that achieved following CC-exposure. HTP and CC significantly increased neutrophil numbers compared to EC. All products augmented numbers of B cells, T cells, and pro-inflammatory IL17A+ T cells in the lungs. Decreased lung antioxidant activity and lung epithelial and endothelial damage was induced by all products. EC and HTP differentially augmented inflammatory cytokines/chemokines in the BAL. Generation of immunity following vaccination was impaired by EC and HTP but to a lesser extent than CC, with a CC > HTP > EC hierarchy of suppression of pulmonary bacterial clearance.

CONCLUSIONS

HTP and EC-aerosols induced a proinflammatory pulmonary microenvironment, lung damage, and suppressed efficacy of vaccination.

A Systematic Evaluation of the SARS-CoV-2 Vaccine-Induced Anti-S-RBD-Ig Response in a Population of Health Care Workers

In the wake of the COVID-19 pandemic, the novel class of mRNA vaccines has been granted first-time approval for active immunization against SARS-CoV-2 alongside the already established viral vector-based vaccines. In this prospective single-center study, we set out to determine the vaccine-induced humoral immune response in a population of 1512 health care employees after the second and third vaccination, respectively. Anti-SARS-CoV-2 receptor-binding domain (RBD) and nucleocapsid antigen antibody concentrations were assessed using commercially available immunoassays. We could show that, in particular, young study subjects aged below 30 years, as well as those with a prior SARS-CoV-2 infection, developed significantly higher antibody concentrations. Our data further suggest that being in physically close contact with formerly SARS-CoV-2-positive people positively affects the post-vaccination response. Surprisingly, study subjects with a BMI > 30 produced the highest anti-S-RBD Ig antibody levels if they had recently received their third vaccination. Also, heterologous dual vaccine regimens consisting of a BNT162b2 and ChAdOx1 n-CoV-19, a homologous triple combination of BNT162b2, and an application of mRNA-1273 as the third vaccine, were most efficient at eliciting a humoral immune response. Our study substantiates existing evidence, but beyond that, scrutinizes the impact of vaccine agents and their respective combinations, as well as different time intervals on humoral immunogenicity.

The Effect of Smoking on Inactivated and mRNA Vaccine Responses Applied to Prevent COVİD-19 in Multiple Sclerosis

Introduction

Coronavirus disease 2019 (COVID-19) is the biggest health challenge of recent times. Studies so far reveal that vaccination is the only way to prevent this pandemic. There may be factors that decrease or increase vaccine effectiveness. In multiple sclerosis (MS), some of these factors may cause changes in the effectiveness of the vaccine, depending on the nature of the disease and disease-modifying treatments (DMT). In this study, we aimed to investigate the relationship between antibody titer and smoking in non-treated and DMT-treated MS patients who received inactivated vaccine (Sinovac) and messenger RNA BNT162b2 (BioNTech) mRNA vaccines.

Method

Vaccine antibody responses were measured between 4-12 weeks after two doses of inactivated vaccine and mRNA vaccines. Patients were separated into 6 groups as: patients with MS without treatment PwMS w/o T, ocrelizumab, fingolimod, interferons (interferon beta-1a and interferon beta-1b), dimethyl fumarate, and teriflunomide. Antibody titers of smokers and non-smokers were compared for both vaccines and for each group.

Results

The study included 798 patients. In the mRNA vaccine group, smokers (n=148; 2982±326 AU/mL) had lower antibody titers compared to the non-smokers (n=244; 5903±545 AU/mL) in total (p=0.020). In the inactivated vaccine group, no significant difference was detected between smokers (n=136; 383±51 AU/mL) and non-smokers (n=270; 388±49 AU/mL) in total (p=0.149). In both vaccine groups, patients receiving ocrelizumab and fingolimod had lower antibody titers than those receiving other DMTs or PwMS w/o T. In untreated MS patients, antibody levels in smokers were lower than in non-smokers in the mRNA vaccine group. No difference was found between antibody levels of smokers and non-smokers in any of the inactivated vaccine groups.

Conclusion

Ocrelizumab and fingolimod have lower antibody levels than PwMS w/o T or other DMTs in both mRNA and inactivated vaccine groups. Smoking decreases antibody levels in the mRNA vaccine group, while it has no effect in the inactivated vaccine group.

Assessment of immunoglobin G (spike and nucleocapsid protein) response to COVID-19 vaccination in Palestine

INTRODUCTION

Many countries have begun immunization programs and established protocols to combat pandemics caused by the SARS-CoV-2 virus. Six months after vaccination, the antibody titers produced by the immunization begin to decline, and individuals whose first immunization (either one or two doses) did not provide adequate protection may require a booster dose.

METHODS

A quantitative cross-sectional survey of 18-year-olds and older was undertaken in the West Bank from June 15 to June 27, 2022. Each participant had 5 mL of blood drawn to be tested for IgG-S, IgG-N, and blood group.

RESULTS

All participants had positive IgG-S results; IgG-S values ranged between 77 and 40,000 AU/ml, with a mean value of 1254 AU/ml. The value of IgG-N ranged from 0 to 139.3 U/ml for all participants, with a mean value of 22.4 U/ml. 64 (37.2%) of the participants demonstrated positive IgG-N screening results, with mean values of 51.2 U/ml. Female participants' mean IgG concentration was higher than male participants. Furthermore, the results revealed that smokers had lower levels of vaccine-induced antibodies than nonsmokers. High significance was found in the time from the last vaccine till the blood sample test (T = 3.848, P < .001), and the group between 6 and 9 months was found to have higher mean values than the 9-months group (M = 15952).

CONCLUSIONS

Participants vaccinated with a higher number of vaccines tend to have higher IgG-S. To elevate total antibodies, booster doses are essential. Additional researchers are needed to examine the positive correlation between IgG-S and IgG-N.

Predictors of long-term neutralizing antibody titers following COVID-19 vaccination by three vaccine types: the BOOST study

As concerns related to the COVID-19 pandemic continue, it is critical to understand the impact of vaccination type on neutralizing antibody response durability as well as to identify individual difference factors related to decline in neutralization. This was a head-to-head comparison study following 498 healthy, community volunteers who received the BNT162b2 (n = 287), mRNA-1273 (n = 149), and Ad26.COV2.S (n = 62). Participants completed questionnaires and underwent blood draws prior to vaccination, 1 month, and 6 months after the vaccination series, and neutralizing antibody (nAB) titers at 1- and 6-months post vaccination were quantified using a high-throughput pseudovirus assay. Over 6 months of follow-up, nABs declined in recipients of BNT162b2 and mRNA-1273, while nABs in recipients of Ad26.COV2.S showed a significant increase. At the 6-month time point, nABs to Ad26.COV2.S were significantly higher than nABs to BNT162b2 and equivalent to mRNA-1273. Irrespective of follow-up timing, being older was associated with lower nAB for participants who received BNT162b2 and Ad26.COV2.S but not for those who received mRNA-1273. A higher baseline BMI was associated with a lower nAB for Ad26.COV2.S recipients but not for recipients of other vaccines. Women and non-smokers showed higher nAB compared to men and current smokers, respectively. The durability of neutralizing antibody responses differed by vaccine type and several sociodemographic factors that predicted response. These findings may inform booster recommendations in the future.

Anti-tumor necrosis factor therapy is associated with attenuated humoral response to SARS-COV-2 vaccines in patients with inflammatory bowel disease

BACKGROUND

Immunosuppressive therapy used in the treatment of inflammatory bowel disease (IBD) is known to reduce vaccine immunogenicity.

AIMS

This study aimed to 1) predict the humoral response elicited by SARS-CoV-2 vaccination in IBD patients based on their ongoing treatment and other relevant patient and vaccine characteristics and 2) assess the humoral response to a booster dose of mRNA vaccine.

METHODS

We conducted a prospective study in adult IBD patients. Anti-spike (S) IgG antibodies were measured after initial vaccination and again after one booster dose. A multiple linear regression model was created to predict anti-S antibody titer following initial complete vaccination in different therapeutic groups (no immunosuppression, anti-TNF, immunomodulators and combination therapy). A two-tailed Wilcoxon test for two dependent groups was performed to compare anti-S values before and after the booster dose.

RESULTS

Our study included 198 IBD patients. The multiple linear regression identified anti-TNF and combination therapy (versus no immunosuppression), current smoking, viral vector (versus mRNA) vaccine and interval between vaccination and anti-S measurement as statistically significant predictors of the log anti-S antibody levels (p < 0.001). No statistically significant differences were found between no immunosuppression and immunomodulators (p = 0.349) and between anti-TNF and combination therapy (p = 0.997). Statistically significant differences for anti-S antibody titer before and after the booster dose of mRNA SARS-CoV-2 vaccine were found, both for non-anti-TNF and anti-TNF groups.

CONCLUSIONS

Anti-TNF treatment (either alone or in combination therapy) is associated with lower anti-S antibody levels. Booster mRNA doses seem to increase anti-S both in non-anti-TNF and anti-TNF treated patients. Special attention should be paid to this group of patients when planning vaccination schemes.

Humoral and Cellular Response and Associated Variables Nine Months following BNT162b2 Vaccination in Healthcare Workers

In this study, we aimed to illustrate the trajectory of humoral and cellular immunity nine months after primary vaccination with the BNT162b2 mRNA vaccine among 189 healthcare workers (HCWs). Additionally, we endeavored to identify correlations between immunity parameters and a number of common variables and comorbidities. A total of 189 healthcare workers (HCWs), vaccinated against COVID-19, were finally included in the study. All of the subjects had received two doses of the BNT162b2 vaccine; had undergone antibody tests one, four and nine months post-vaccination; and had completed a medical questionnaire. Further samples taken at nine months were tested for cellular immunity. No participants had evidence of COVID-19 infection pre- or post-vaccination. An anti-S1 receptor binding domain (RBD) antibody assay was used to assess humoral response, and cellular immunity was estimated with an INF-γ release assay (IGRA). Statistical analysis was performed using STATA. We report a statistically significant antibody drop over time. Being above the age of 40 or a smoker reduces the rise of antibodies by 37% and 28%, respectively. More than half of the participants did not demonstrate T-cell activation at nine months. Female gender and antibody levels at four months predispose detection of cellular immunity at nine months post-immunization. This study furthers the qualitative, quantitative, and temporal understanding of the immune response to the BNT162b2 mRNA vaccine and the effect of correlated factors.

Factors associated with receipt of COVID-19 vaccination and SARS-CoV-2 seropositivity among healthcare workers in Albania (February 2021-June 2022): secondary analysis of a prospective cohort study

Background

Healthcare workers (HCWs) have been disproportionally affected by COVID-19. We investigated factors associated with two- and three-dose COVID-19 vaccine uptake and SARS-CoV-2 seropositivity among 1504 HCWs enrolled (19 February-7 May 2021) in a prospective COVID-19 vaccine effectiveness cohort in Albania through a secondary analysis.

Methods

We collected sociodemographic, occupational, health, prior SARS-CoV-2 infection, and COVID-19 vaccination data from all HCWs at enrollment. Vaccination status was assessed weekly through June 2022. A serum sample was collected from all participants at enrollment and tested for anti-spike SARS-CoV-2 antibodies. We analyzed HCWs characteristics and outcomes using multivariable logistic regression.

Findings

By 11 June 2022, 1337 (88.9%) HCWs had received two COVID-19 vaccine doses, of whom 255 (19.1%) received a booster. Factors significantly associated with receiving three doses (adjusted odds ratio (aOR), 95% CIs) were being ≥35 years (35-44 years: 1.76 (1.05-2.97); 45-54 years: 3.11 (1.92-5.05); ≥55 years: 3.38 (2.04-5.59)) and vaccinated against influenza (1.78; 1.20-2.64). Booster dose receipt was lower among females (0.58; 0.41-0.81), previously infected (0.67; 0.48-0.93), nurses and midwives (0.31; 0.22-0.45), and support staff (0.19; 0.11-0.32). Overall 1076 (72%) were SARS-CoV-2 seropositive at enrollment. Nurses and midwifes (1.45; 1.05-2.02), support staff (1.57; 1.03-2.41), and HCWs performing aerosol-generating procedures (AGPs) (1.40; 1.01-1.94) had higher odds of being seropositive, while smokers had reduced odds (0.55; 0.40-0.75).

Interpretation

In a large cohort of Albanian HCWs, COVID-19 vaccine booster dose uptake was very low, particularly among younger, female, and non-physician HCWs, despite evidence demonstrating the added benefit of boosters in preventing infection and severe disease. Reasons behind these disparities should be explored to develop targeted strategies in order to promote uptake in this critical population. SARS-CoV-2 seroprevalence was higher among non-physicians and HCWs performing APGs. A better understanding of the factors contributing to these differences is needed to inform interventions that could reduce infections in the future.

Funding

This study was funded by the Task Force for Global Health (US Centers for Disease Control (CDC) cooperative agreement # NU51IP000873) and the World Health Organization, Regional Office for Europe.

Humoral responses to the CoronoVac vaccine in healthcare workers

BACKGROUND

This study aimed to assess the immunoglobulin G (IgG) antibody response rate in emergency department (ED) healthcare workers (HCWs) and potential adverse effects after CoronaVac vaccination.

METHODS

All included HCWs were grouped based on the previous history of coronavirus disease 2019 (COVID-19) and the number of vaccinations. Furthermore, the IgG antibody response was evaluated based on the sex and smoking status of HCWs. Those with a cut-off index of ≥1.00 after vaccination with CoronaVac were considered to have had COVID-19 and had an adequate humoral response.

RESULTS

Among 224 ED HCWs, 18% experienced the adverse effects of CoronaVac vaccine, the most prevalent being pain in the injection site. The IgG antibody response rate was 20% after the first dose of vaccine, while the response rate increased to 90% after the second dose. Female HCWs had higher IgG response rates compared with male HCWs (53.8 [15.9-147.0] vs 31.2 [4.5-124.0]). Non-smokers had higher IgG response rate compared with smokers (49.0 [11.5-160.5] vs 23.1 [7.4-98.5]).

CONCLUSION

A single dose of CoronaVac does not produce a sufficient antibody response; hence, two doses are recommended. Men have a lower IgG response compared with women. Smokers had a lower IgG response rate compared with non-smokers. Therefore, it may be necessary to carefully assess the humoral responses of men and smokers when implementing a community vaccination program.

Escalating spread of SARS-CoV-2 infection after school reopening among students in hotspot districts of Oromia Region in Ethiopia: Longitudinal study

BACKGROUND

COVID-19 pandemic caused by extended variants of SARS-CoV-2 has infected more than 350 million people, resulting in over 5.5 million deaths globally. However, the actual burden of the pandemic in Africa, particularly among children, remains largely unknown. We aimed to assess the seroepidemiological changes of SARS-CoV-2 infection after school reopening among school children in Oromia, Ethiopia.

METHODS

A prospective cohort study involving students aged 10 years and older were used. A serological survey was performed twice, at school reopening in December 2020 and four months later in April 2021. Participants were selected from 60 schools located in 15 COVID-19 hotspot districts in Oromia Region. Serology tests were performed by Elecsys anti-SARS-CoV-2 nucleocapsid assay. Data were collected using CSentry CSProData Entry 7.2.1 and exported to STATA version 14.2 for data cleaning and analysis.

RESULTS

A total of 1884 students were recruited at baseline, and 1271 completed the follow-up. SARS-CoV-2 seroprevalence almost doubled in four months from 25.7% at baseline to 46.3% in the second round, with a corresponding seroincidence of 1910 per 100,000 person-week. Seroincidence was found to be higher among secondary school students (grade 9-12) compared to primary school students (grade 4-8) (RR = 1.6, 95% CI 1.21-2.22) and among those with large family size (> = 5) than those with a family size of <3 (RR = 2.1, 95% CI 1.09-4.17). The increase in SARS-CoV-2 seroprevalence among the students corresponded with Ethiopia's second wave of the COVID-19 outbreak.

CONCLUSION

SARS-CoV-2 seroprevalence among students in hotspot districts of the Oromia Region was high even at baseline and almost doubled within four months of school recommencement. The high seroincidence coincided with the second wave of the COVID-19 outbreak in Ethiopia, indicating a possible contribution to school opening for the new outbreak wave.

Risk of Repeated Adverse Effects following Booster Dose of mRNA COVID-19 Vaccine: Results from the MOSAICO Study

The successful deployment of safe and effective vaccines against coronavirus disease 2019 (COVID-19) has been crucial in reducing the global disease burden. Owing to the need for vaccination series over time, continuous observational studies are needed to estimate the COVID-19 vaccine response in real-world conditions. In particular, the detection, assessment, and understanding of adverse effects following immunization (AEFI) with a COVID-19 vaccine are crucial to better address vaccination strategies. Therefore, this study aimed to investigate the risk of repeated AEFI post-administration of a booster dose of mRNA COVID-19 vaccine in a sample of healthcare workers (HCWs) in an Italian teaching hospital. The data on any local and systemic AEFI were studied in multivariate Poisson regression analyses to model the association between the incidence of each postvaccination symptom and its prior reporting after the administration of the previous doses. Overall, compared with the primary vaccination series, the majority of post-third dose AEFI were less reported. The results from multivariable models showed that the likelihood of reporting an AEFI after the third dose was higher in those who experienced the same postvaccination symptom after the second dose (all AEFI except for itch at injection site) and, although not significant for all AEFI, after the first dose. Any associations with age, gender, smoking habits, previous SARS-CoV-2 infection and other characteristics, as well as the health impact of AEFI were also assessed. Taken together, the results from this research support reframe AEFI symptoms as signals of a robust postvaccination reaction as well as of common vaccine response, and they add important data to inform booster vaccination strategies in HCWs and, extensively, in the adult population.

Towards a Future of Personalized Vaccinology: Study on Individual Variables Influencing the Antibody Response to the COVID-19 Vaccine

The COVID-19 pandemic has hugely impacted many different aspects of human health, and vaccination is one of the most effective weapons to manage it. However, many different factors, such as age, gender, comorbidities and lifestyles, play a role in the response to infections and vaccines. We carried out this study to evaluate the potential role played by some individual factors in the production of anti-COVID-19 antibodies in the light of personalized and future vaccinology. We conducted an observational study consisting of a retrospective phase, exploiting previous data about anti-COVID-19 antibody responses, with a prospective phase to investigate individual variables through the use of a questionnaire. The antibody response after the COVID-19 vaccination was inversely related to old age, increased BMI and the number of smoking years, while a positive correlation was found with moderate alcohol consumption and especially with circulating levels of vitamin D, as clearly shown by the multivariate regression analysis. Our study showed that a number of variables are involved in the COVID-19 vaccine antibody response. These findings are very important and can be considered in the light of a future and personalized vaccinology.

The prevalence of SARS-CoV-2 antibodies within the community of a private tertiary university in the Philippines: A serial cross sectional study

The COVID-19 pandemic has caused a public health emergency in all sectors of society, including universities and other academic institutions. This study determined the seroprevalence of SARS-CoV-2 antibodies among administrators, faculty, staff, and students of a private tertiary academic institution in the Philippines over a 7 month period. It employed a serial cross-sectional method using qualitative and quantitative COVID-19 antibody test kits. A total of 1,318 participants were tested, showing 47.80% of the study population yielding IgG antibodies to SARS-CoV-2 virus. A general increase in seroprevalence was observed from June to December 2021, which coincided with the vaccine roll-out of the country. All brands yielded positive antibody formation, with mRNA vaccines having higher levels than other types of vaccines. A decreasing trend in IgG reactivity was found in vaccinated individuals after 1 to 6 months of completion of the 2 doses of the COVID-19 vaccine. Where possible, IgG and T-cell reactivity and/or neutralizing capacity against SAR-CoV-2 need to be monitored regardless of vaccine brand. Together with uptake of COVID-19 vaccines and boosters, other public health interventions such as wearing of masks and regular testing need to be continued for better protection. Effective communication is also needed to inform risks associated with activities across different settings. Investments in long-term measures such as air filtration and ventilation systems, and wastewater surveillance need to be made.

Humoral and cellular immune response after severe acute respiratory syndrome coronavirus 2 messenger ribonucleic acid vaccination in heart transplant recipients: An observational study in France

INTRODUCTION

Heart transplant (HT) recipients have a high risk of developing severe COVID-19. Immunoglobulin G antibodies are considered to provide protective immunity and T-cell activity is thought to confer protection from severe disease. However, data on T-cell response to mRNA vaccination in a context of HT remains limited.

METHODS

In 96 HT patients, a IFN-γ release assay and an anti-Spike antibody test were used to evaluate the ability of SARS-CoV-2 mRNA vaccines to generate cellular and humoral immune response. Blood samples were collected few weeks to 7 months after vaccination. Multiple fractional polynomial and LASSO regression models were used to define predictors of T-cell response.

RESULTS

Three to five months after vaccination, three doses of vaccine induced a positive SARS-CoV-2 T-cell response in 47% of recipients and a positive humoral response in 83% of recipients, 11.1% of patients remained negative for both T and B cell responses. Three doses were necessary to reach high IgG response levels (>590 BAU/mL), which were obtained in a third of patients. Immunity was greatly amplified in the group who had three vaccine doses plus COVID-19 infection.

CONCLUSION

Our study revealed that T and B immunity decreases over time, leading us to suggest the interest of a booster vaccination at 5 months after the third dose. Moreover, a close follow-up of immune response following vaccination is needed to ensure ongoing immune protection. We also found that significant predictors of higher cellular response were infection and active smoking, regardless of immunosuppressive treatment with mycophenolate mofetil (MMF).

Third BNT162b2 Vaccine Booster Dose against SARS-CoV-2-Induced Antibody Response among Healthcare Workers

This study assessed humoral response to the third BNT162b2 dose among healthcare workers (HCW). This prospective cohort study of HCW tested for anti-spike antibodies (LIAISON SARS-CoV-2 S1/S2 IgG assay) at 1, 3, 6, 9, and 12 months after receiving the second BNT162b2 vaccine dose (tests 1, 2, 3, 4, and 5, respectively). A third (booster) vaccination dose was introduced before test 4. Linear regression model was used to determine the humoral response following vaccine doses. For each serology test, changes in log-transformed antibody concentrations over time, adjusted for age, sex, underlying diseases, steroid treatment, and smoking were described using the general linear mix model. Serology tests were performed at 3, 6, 9, and 12 months after the second vaccine dose in 1113, 1058, 986, and 939 participants, respectively. The third dose was received by 964 participants before the 9-month tests, 797 of whom participated in the 9- and 12-month serology tests. A significant inverse correlation was noted between time from third dose and antibody concentrations (Spearman correlation −0.395; p < 0.001). Age (p < 0.0001; CI 95% −0.005−−0.004), heart disease (p < 0.0001; CI 95% −0.177−−0.052), immunodeficiency (p < 0.0001; CI 95% 0.251−−0.106), and smoking (p < 0.0001; CI 95% −0.122−−0.040) were significantly associated with decreased antibody concentrations. Female sex (p = 0.03; CI 95% 0.013−0.066) was associated with increased antibody concentrations. The third booster dose had a better effect on immunogenicity, with higher antibody concentrations among tested HCW. Heart disease, smoking, and other known risk factors were associated with decreased antibody concentrations.

Determinants of Antibody Responses to SARS-CoV-2 Vaccines: Population-Based Longitudinal Study (COVIDENCE UK)

Antibody responses to SARS-CoV-2 vaccines vary for reasons that remain poorly understood. A range of sociodemographic, behavioural, clinical, pharmacologic and nutritional factors could explain these differences. To investigate this hypothesis, we tested for presence of combined IgG, IgA and IgM (IgGAM) anti-Spike antibodies before and after 2 doses of ChAdOx1 nCoV-19 (ChAdOx1, AstraZeneca) or BNT162b2 (Pfizer-BioNTech) in UK adults participating in a population-based longitudinal study who received their first dose of vaccine between December 2020 and July 2021. Information on sixty-six potential sociodemographic, behavioural, clinical, pharmacologic and nutritional determinants of serological response to vaccination was captured using serial online questionnaires. We used logistic regression to estimate multivariable-adjusted odds ratios (aORs) for associations between independent variables and risk of seronegativity following two vaccine doses. Additionally, percentage differences in antibody titres between groups were estimated in the sub-set of participants who were seropositive post-vaccination using linear regression. Anti-spike antibodies were undetectable in 378/9101 (4.2%) participants at a median of 8.6 weeks post second vaccine dose. Increased risk of post-vaccination seronegativity associated with administration of ChAdOx1 vs. BNT162b2 (adjusted odds ratio (aOR) 6.6, 95% CI 4.2−10.4), shorter interval between vaccine doses (aOR 1.6, 1.2−2.1, 6−10 vs. >10 weeks), poor vs. excellent general health (aOR 3.1, 1.4−7.0), immunodeficiency (aOR 6.5, 2.5−16.6) and immunosuppressant use (aOR 3.7, 2.4−5.7). Odds of seronegativity were lower for participants who were SARS-CoV-2 seropositive pre-vaccination (aOR 0.2, 0.0−0.6) and for those taking vitamin D supplements (aOR 0.7, 0.5−0.9). Serologic responses to vaccination did not associate with time of day of vaccine administration, lifestyle factors including tobacco smoking, alcohol intake and sleep, or use of anti-pyretics for management of reactive symptoms after vaccination. In a sub-set of 8727 individuals who were seropositive post-vaccination, lower antibody titres associated with administration of ChAdOx1 vs. BNT162b2 (43.4% lower, 41.8−44.8), longer duration between second vaccine dose and sampling (12.7% lower, 8.2−16.9, for 9−16 weeks vs. 2−4 weeks), shorter interval between vaccine doses (10.4% lower, 3.7−16.7, for <6 weeks vs. >10 weeks), receiving a second vaccine dose in October−December vs. April−June (47.7% lower, 11.4−69.1), older age (3.3% lower per 10-year increase in age, 2.1−4.6), and hypertension (4.1% lower, 1.1−6.9). Higher antibody titres associated with South Asian ethnicity (16.2% higher, 3.0−31.1, vs. White ethnicity) or Mixed/Multiple/Other ethnicity (11.8% higher, 2.9−21.6, vs. White ethnicity), higher body mass index (BMI; 2.9% higher, 0.2−5.7, for BMI 25−30 vs. <25 kg/m2) and pre-vaccination seropositivity for SARS-CoV-2 (105.1% higher, 94.1−116.6, for those seropositive and experienced COVID-19 symptoms vs. those who were seronegative pre-vaccination). In conclusion, we identify multiple determinants of antibody responses to SARS-CoV-2 vaccines, many of which are modifiable.

The effect of laboratory-verified smoking on SARS-CoV-2 infection: results from the Troina sero-epidemiological survey

Previous research yielded conflicting results on the association between cigarette smoking and risk of SARS-CoV-2 infection. Since the prevalence of smoking is high globally, the study of its impact on COVID-19 pandemic may have considerable implications for public health. This study is the first to investigate the association between the SARS-CoV-2 antibody sero-positivity and biochemically verified smoking status, to refine current estimates on this association. SARS-CoV-2-specific IgG and serum cotinine levels (a well-known marker of tobacco exposure) were assessed in a large sero-epidemiological survey conducted in the town of Troina (Sicily, Italy). A propensity score matching was carried out to reduce the effect of possible factors on SARS-CoV-2 infection risk among study participants. Of the 1785 subjects included in our study, one-third was classified as current smokers, based on serum cotinine levels. The overall proportion of subjects with positive serology for SARS-CoV-2 IgG was 5.4%. The prevalence of SARS-CoV-2 antibody positivity and previous COVID-19 diagnosis were reduced in smokers. This reduced prevalence persisted after adjusting for possible confounders (such as sex, age, previous infection, chronic conditions, and risk group) at regression analyses, and the point estimates based on the PS-matched models resulted consistent with those for the unmatched population. This study found a lower proportion of positive SARS-CoV-2 serology among current smokers, using direct laboratory measures of tobacco exposure and thus avoiding possible bias associated with self-reported smoking status. Results may also serve as a reference for future clinical research on potential pharmaceutical role of nicotine or nicotinic-cholinergic agonists against COVID-19.

Time-Varying Effect of Hybrid Immunity on the Risk of Breakthrough Infection after Booster Dose of mRNA COVID-19 Vaccine: The MOSAICO Study

This longitudinal observational study investigated the risk of breakthrough SARS-CoV-2 infection up to 6 months after a booster dose of an mRNA COVID-19 vaccine in infection-naïve vs. previously infected healthcare workers (HCWs), and whether this difference varied over time. A Cox proportional hazard regression model with Aalen’s additive analysis was fitted to examine the association between the risk of infections and predictor variables. Overall, we observed an incidence rate of 2.5 cases per 1000 person-days (95% confidence interval [CI] 2.0–3.0), which dropped at 0.8 per 1000 person-days (95% CI 0.3–2.0) in recipients with prior SARS-CoV-2 infection. The fitted analysis indicated an adjusted hazard ratio of 0.32 (95% CI 0.13–0.80; p-value = 0.01) for those with hybrid immunity with a slope that became steeply negative roughly starting from day 90. No difference was seen according to participants’ smoking habits. Characteristics of infected HCWs were also described. Our study quantifies the time-varying effects of vaccine-induced and hybrid immunity after the booster dose (during the Omicron variant predominance in Italy) and observed that the protection waned more rapidly in infection-naïve recipients starting from the third month. The results add important evidence that can be used to inform COVID-19 vaccination strategies.

Use of heated tobacco products, moderate alcohol drinking, and anti-SARS-CoV-2 IgG antibody titers after BNT162b2 vaccination among Japanese healthcare workers

The effect of heated tobacco products (HTPs) use and moderate alcohol drinking on immunogenicity to coronavirus disease (COVID-19) vaccines remain elusive. This study aimed to examine the association of tobacco product use and alcohol consumption with anti-SARS-CoV-2 spike IgG antibody titers after the BNT162b2 vaccine. Participants were 3433 healthcare workers receiving two vaccine doses in the 4 national centers for advanced medical and research in Japan. Smoking status and alcohol consumption were assessed via a questionnaire, and anti-SARS-CoV-2 spike IgG titers were measured with chemiluminescent enzyme immunoassay using serum collected on the median of 64 days after the second vaccination. Multilevel linear regression models were used to estimate the geometric mean titers (GMT) and the ratios of means (RoM) between groups with adjustment for covariates. Compared with never-smokers (GMT = 118), IgG antibody titers were significantly lower among HTPs users (including those who also smoked cigarettes) (GMT = 105; RoM = 0.89 [95%CI: 0.78-0.99]) and exclusive cigarettes smokers (GMT = 98; RoM = 0.81 [95%CI: 0.71-0.92]). Compared with non-drinkers of alcohol (GMT = 123), alcohol drinkers consuming <1 go/day (GMT = 113; RoM = 0.93 [95%CI: 0.88-0.98]), 1-1.9 go/day (GMT = 104; RoM = 0.85 [95%CI: 0.78-0.93]), and ≥ 2 go/day (GMT = 103; RoM = 0.84 [95%CI: 0.74-0.96]) had significantly lower antibody titers (P for trend<0.01). Spline analysis showed a large reduction of antibody until around 1 go/day of alcohol consumption, and then they gradually decreased. Results suggest that in addition to conventional cigarette smoking and heavy alcohol drinking, HTPs use and moderate alcohol drinking may be predictors of lower immunological response to COVID-19 vaccine.

SARS-CoV-2 seroprevalence in healthcare workers and risk factors

BACKGROUND

Exposure of healthcare workers (HCW) to SARS-CoV-2 is a public health concern. Not only are HCWs particularly exposed to SARS-CoV-2, but their contamination can also weaken the healthcare system.

METHODS

We analyzed exposure of French University Hospital HCWs to SARS-CoV-2 through history of positive RT-PCR test and SARS-CoV-2 seroprevalence. Potential risk factors, such as age, BMI, having children or not, working in a COVID-19 unit, or smoking were explored.

RESULTS

From May to June 2020, among the 8960 employees of the University Hospital of Nancy, a serological test was performed in 4696 HCWs. The average (SD) age was 40.4 (11.4) years, and the sample included 3926 women (83.6%). Of the 4696 HCWs, 1050 were smokers (22.4%). Among them, 2231 HCWs had a history of COVID-19 symptoms and/or flu-like syndrome (47.5%) and 238 were seropositive (5.1%). Neither gender, sex, BMI, nor having children were associated with a history of positive RT-PCR test or seropositive status. Previous work in a COVID-19 unit was associated with a history of positive RT-PCR test (p = 0.045), but not with seroprevalence (p = 0.215). As expected, history of COVID-19 clinical manifestations was more frequent in HCWs with positive serology than in HCWs with negative serology (adjusted OR = 1.9, 95%CI [1.4-2.5], p < 0.001). Less expected, smoking was associated with a reduced risk of seropositivity among HCWs (adjusted OR = 0.6, 95%CI [0.4-0.9], p = 0.019).

CONCLUSION

HCW are patently exposed to SARS-CoV-2. Care to COVID-19 patients was not associated with a higher SARS-CoV-2 seroprevalence. Smoking appears here associated to a lower seroprevalence.

Antibody Response to COVID-19 mRNA Vaccines in Oncologic and Hematologic Patients Undergoing Chemotherapy

BACKGROUND

Information on immune responses in cancer patients following mRNA COVID-19 vaccines is still insufficient, but generally, patients had impaired serological responses, especially those with hematological malignancies. We evaluated serological response to COVID-19 mRNA vaccine in cancer patients receiving chemotherapy compared with healthy controls.

METHODS

In total, 195 cancer patients and 400 randomly selected controls who had been administered a Pfizer-BioNTech or Moderna COVID-19 vaccines in two doses were compared. The threshold of positivity was 4.33 BAU/mL. Patients were receiving anticancer treatment after the first and second dose of the vaccines.

RESULTS

a TOTAL OF 169 patients (87%) had solid tumors and 26 hemolymphopoietic diseases. Seropositivity rate was lower in patients than controls (91% vs. 96%), with an age/gender-adjusted rate ratio (RR) of 0.95 (95% CL = 0.89-1.02). Positivity was found in 97% of solid cancers and in 50% of hemolymphopoietic tumors. Both advanced and adjuvant therapy seemed to slightly reduce seropositivity rates in patients when compared to controls (RR = 0.97, 95% CL = 0.89-1.06; RR = 0.94, 95% CL = 0.87-1.01).

CONCLUSIONS

the response to vaccination is similar in patients affected by solid tumors to controls. On the contrary, hemolymphopietic patients show a much lower response than controls.

Patients with Liver Cirrhosis Show High Immunogenicity upon COVID-19 Vaccination but Develop Premature Deterioration of Antibody Titers

SARS-CoV-2 infection is known to lead to severe morbidity and mortality in patients with liver cirrhosis. For this reason, vaccination of these patients against COVID-19 is widely recommended. However, data regarding immunogenicity in patients with liver cirrhosis is limited and even less is known about the kinetics of antibody response, as well as the optimal timing of booster immunization. We analyzed immunogenicity in 110 patients with liver cirrhosis after receiving two doses of the mRNA-based vaccine BNT162b2 following the standard protocol and compared these results to a control group consisting of 80 healthcare workers. One hundred and six patients with liver cirrhosis (96%) developed antibodies against SARS-CoV-2, compared to 79 (99%) in the control group (p = 0.400). Still, the median SARS-CoV-2 IgG titer was significantly lower in patients with liver cirrhosis compared to the control group (939 vs. 1905 BAU/mL, p = 0.0001). We also analyzed the strength of the antibody response in relation to the time between the second dose and antibody detection. Antibody titers remained relatively stable in the control group while showing a rapid and significant decrease in patients with liver cirrhosis. In conclusion, our data reveals a favorable initial outcome after vaccination with the COVID-19 vaccine BNT162b2 in cirrhotic patients but show a rapid deterioration of the antibody response after time, thereby giving a strong hint towards the importance of early booster immunization for this group of patients.

The Effect of Smoking on Humoral Response to COVID-19 Vaccines: A Systematic Review of Epidemiological Studies

While the role of active smoking on response to vaccines is yet to be fully understood, some real-world studies have outlined a possible link between smoking and humoral response to COVID-19 vaccines. Thus, the present rapid systematic review aimed at summarizing the current epidemiological evidence on this association. Following PRISMA and WHO guidelines on rapid systematic reviews, we systematically reviewed published literature on this topic and discussed the findings according to the aim of analysing smoking and its impact on humoral response to COVID-19 postvaccination antibody titres. The search strategy yielded a total of 23 articles. The sample size amongst the studies ranged between 74 and 3475 participants (median, 360), with the proportion of smokers being between 4.2% and 40.8% (median, 26.0%). The studies included in this review analysis investigated the dynamics of antibody response to different type of COVID-19 vaccines. In 17 out of 23 studies, current smokers showed much lower antibody titres or more rapid lowering of the vaccine-induced IgG compared with nonsmokers. This rapid systematic review indicates that active smoking negatively impacts humoral response to COVID-19 vaccines, although the pathophysiologic mechanisms for this association have not been entirely suggested. The results advocate targeted policies to promote tailored health promotion initiatives, which can increase risk perception and ensure appropriate protection measures to be taken to avoid the health consequences of COVID-19 in smokers.