Effectiveness of COVID-19 vaccines against SARS-CoV-2 variants of concern: a systematic review and meta-analysis

A retrospective survey on the effectiveness of vaccines administered to individuals in China with regard to inactivated COVID-19 vaccines, Ad5-nCoV and/or aerosolized Ad5-nCoV

We administered a questionnaire to participants who received different vaccination regimens to evaluate the effectiveness of Ad5-vectored COVID-19 vaccines. The results showed that administration of intramuscular Ad5-nCoV provided 21.32% more protection against SARS-CoV-2 infection than that of the inactivated COVID-19 vaccine in people who had received only one type of COVID-19 vaccine. Furthermore, aerosolized Ad5-nCoV exhibited good protection, whether it was administered as a homologous booster to people vaccinated with the intramuscular Ad5-nCoV or as a heterologous booster to people vaccinated with inactivated COVID-19 vaccines. Our research indicates that Ad5-nCoV is an effective booster. This finding supports the future selection of COVID-19 immunization strategies.

Efficacy of the COVID-19 vaccination in patients with asymptomatic or mild illness during the Omicron epidemic in Guangzhou: a multi-centre retrospective cohort study

BACKGROUND

Despite the widespread administration of coronavirus disease 2019 (COVID-19) vaccines, the impact on patients with asymptomatic to mild illness remains unclear. Here, we aimed to assess the efficacy of various vaccine doses and types on the duration of isolation duration and discharge rates, the viral shedding duration, and negative rates in asymptomatic to mild COVID-19 patients.

METHODS

We included adult patients at the Fangcang isolation centres in Pazhou or Yongning between November and December 2022. We analysed data on basic demographics, admission details, laboratory indicators and vaccination information.

RESULTS

A total of 6560 infected patients were included (3584 from Pazhou and 2976 from Yongning). Of these, 90.6% received inactivated vaccines, 3.66% received recombinant SARS-CoV-2 spike protein subunit vaccines and 0.91% received adenovirus vaccines. Among the 6173 vaccinated individuals, 71.9% received a booster dose. By day 9, the isolation rate reached 50% among vaccinated patients. On day 7.5, the positive rate among vaccinated individuals reached 50%.

CONCLUSIONS

Full vaccination was effective, with heterologous vaccines showing greater efficacy than inactivated vaccines alone. However, there was no significant difference in the vaccine protective effect 12 months after vaccination.

COVID-19 mutations: An overview

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) belongs to the genus Beta coronavirus and the family of Coronaviridae. It is a positive-sense, non-segmented single-strand RNA virus. Four common types of human coronaviruses circulate globally, particularly in the fall and winter seasons. They are responsible for 10%-30% of all mild upper respiratory tract infections in adults. These are 229E, NL63 of the Alfacoronaviridae family, OC43, and HKU1 of the Betacoronaviridae family. However, there are three highly pathogenic human coronaviruses: SARS-CoV-2, Middle East respiratory syndrome coronavirus, and the latest pandemic caused by the SARS-CoV-2 infection. All viruses, including SARS-CoV-2, have the inherent tendency to evolve. SARS-CoV-2 is still evolving in humans. Additionally, due to the development of herd immunity, prior infection, use of medication, vaccination, and antibodies, the viruses are facing immune pressure. During the replication process and due to immune pressure, the virus may undergo mutations. Several SARS-CoV-2 variants, including the variants of concern (VOCs), such as B.1.1.7 (Alpha), B.1.351 (Beta), B.1.617/B.1.617.2 (Delta), P.1 (Gamma), and B.1.1.529 (Omicron) have been reported from various parts of the world. These VOCs contain several important mutations; some of them are on the spike proteins. These mutations may lead to enhanced infectivity, transmissibility, and decreased neutralization efficacy by monoclonal antibodies, convalescent sera, or vaccines. Mutations may also lead to a failure of detection by molecular diagnostic tests, leading to a delayed diagnosis, increased community spread, and delayed treatment. We searched PubMed, EMBASE, Covariant, the Stanford variant Database, and the CINAHL from December 2019 to February 2023 using the following search terms: VOC, SARS-CoV-2, Omicron, mutations in SARS-CoV-2, etc. This review discusses the various mutations and their impact on infectivity, transmissibility, and neutralization efficacy.

Estimate the number of lives saved by a SARS-CoV-2 vaccination campaign in six states in the United States with a simple model

Objectives

Vaccination and the emergence of the highly transmissible Omicron variant changed the fate of the COVID-19 pandemic. It is very challenging to estimate the number of lives saved by vaccination given the multiple doses of vaccination, the time-varying nature of transmissibility, the waning of immunity, and the presence of immune evasion.

Methods

We established a S-SV-E-I-T-D-R model to simulate the number of lives saved by vaccination in six states in the United States (U.S.) from March 5, 2020, to March 23, 2023. The cumulative number of deaths were estimated under three vaccination scenarios based on two assumptions. Additionally, immune evasion by the Omicron and loss of protection afforded by vaccination or infection were considered.

Results

The number of deaths averted by COVID-19 vaccinations (including three doses) ranged from 0.154-0.295% of the total population across six states. The number of deaths averted by the third dose ranged from 0.008-0.017% of the total population.

Conclusions

Our estimate of death averted by COVID-19 vaccination in the U.S. was largely in line with an official estimate (at a level of 0.15-0.20% of the total population). We found that the additional contribution of the third dose was small but significant.

A spike-based mRNA vaccine that induces durable and broad protection against porcine deltacoronavirus in piglets

Coronaviruses (CoVs) are important pathogens for humans and other vertebrates, causing severe respiratory and intestinal infections that have become a threat to public health because of the potential for interspecies transmission between animals and humans. Therefore, the development of safe, effective vaccines remains a top priority for the control of CoV infection. The unique immunological characteristics of vaccines featuring messenger RNA (mRNA) present an advantageous tool for coronavirus vaccine development. Here, we designed two lipid nanoparticle (LNP)-encapsulated mRNA (mRNA-LNP) vaccines: one encoding full-length spike (S) protein and the other encoding the spike ectodomain (Se) from porcine deltacoronavirus (PDCoV). Fourteen days after primary immunization, both mRNA vaccines induced high levels of immunoglobulin G and neutralizing antibodies in mice, with the S vaccine showing better performance than the Se vaccine. Passive immune protection of the S mRNA vaccine in suckling piglets was confirmed by the induction of robust PDCoV-specific humoral and cellular immune responses. The S mRNA vaccine also showed better protective effects than the inactivated vaccine. Our results suggest that the novel PDCoV-S mRNA-LNP vaccine may have the potential to combat PDCoV infection.

IMPORTANCE

As an emerging porcine enteropathogenic coronavirus, porcine deltacoronavirus (PDCoV) has the potential for cross-species transmission, attracting extensive attention. Messenger RNA (mRNA) vaccines are a promising option for combating emerging and re-emerging infectious diseases, as evidenced by the demonstrated efficacy of the COVID-19 mRNA vaccine. Here, we first demonstrated that PDCoV-S mRNA-lipid nanoparticle (LNP) vaccines could induce potent humoral and cellular immune responses in mice. An evaluation of passive immune protection of S mRNA vaccines in suckling piglets confirmed that the protective effect of mRNA vaccine was better than that of inactivated vaccine. This study suggests that the PDCoV-S mRNA-LNP vaccine may serve as a potential and novel vaccine candidate for combating PDCoV infection.

Impact of mesalazine on the response to COVID-19 vaccination in patients with inflammatory bowel disease: Results of a prospective multicentre study of GETECCU (VACOVEII study)

OBJECTIVE

The recommendations of the Spanish Ministry of Health on vaccination in risk groups include mesalazine among the treatments with a possible negative effect on its effectiveness. However, this is not the recommendation of most experts. Our objective was to evaluate the effect of mesalazine on the humoral response to the SARS-CoV-2 vaccine in patients with inflammatory bowel disease (IBD).

METHODS

VACOVEII is a Spanish, prospective, multicenter study promoted by GETECCU, which evaluates the effectiveness of the SARS-CoV-2 vaccine in patients with IBD. This study includes IBD patients who have recieved the full vaccination schedule and without previous COVID-19 infection. Seroconversion was set at 260BAU/mL (centralized determination) and was assessed 6 months after full vaccination. In this subanalysis of the study, we compare the effectiveness of the vaccine between patients treated with mesalazine and patients without treatment.

RESULTS

A total of 124 patients without immunosuppressive therapy were included, of which 32 did not receive any treatment and 92 received only mesalazine. Six months after full vaccination, no significant differences are observed in the mean concentrations of IgG anti-S between both groups. In the multivariate analysis, antibody titers were independently associated with the use of mRNA vaccines and with SARS-CoV-2 infection.

CONCLUSION

Mesalazine does not have a negative effect on the response to SARS-CoV-2 vaccines in IBD patients.

Estimating vaccine effectiveness against COVID-19 using cause-specific sick leave as an indicator: a nationwide population-based cohort study, Norway, July 2021 - December 2022

BACKGROUND

Due to changes in testing policy and increased use of rapid tests, other indicators for SARS-CoV-2 infections are needed to monitor vaccine effectiveness (VE). We aimed to estimate VE against COVID-19 sick leave (> 3 days, certified by a medical professional) among employed individuals (25-64-years-old) in Norway.

METHODS

We performed a nationwide cohort study by collating data from the Emergency preparedness register for COVID-19. We used adjusted Cox proportional hazard models with vaccine status as a time-varying covariate and presented results as adjusted hazard ratios (aHRs) with corresponding 95% confidence intervals. Separate models were run against sick leave and against SARS-CoV-2 infections during the Delta period (June-December 2021), and against sick leave during the Omicron period (January-December 2022) when SARS-CoV-2 PCR-testing was replaced by rapid self-tests and infections were underreported.

RESULTS

We included 2,236,419 individuals during the Delta period, of whom 73,776 (3.3%) had a reported infection and 54,334 (2.4%) were registered with sick leave. Of the 2,206,952 included individuals in the Omicron period, 300,140 (13.6%) were registered with sick leave. During the Delta period, 55% (26,611) of individuals who had registered sick leave also had a positive test, compared to 32% (96,445) during the Omicron period. The VE against sick leave during the Delta period followed a similar waning pattern to that against SARS-CoV-2 infections. After the second and third dose, the lowest aHRs were estimated for 2-7 days after vaccination for both sick leave (0.25; 95%CI 0.24-0.26 and 0.26; 95% CI 0.24-0.29) and infection ( 0.16; 95% CI 0.15-0.17 and 0.18; 95% CI 0.16-0.19) respectively. During the Omicron period, aHRs for sick leave were higher than during the Delta period, but the lowest aHRs were still found in 2-7 weeks after receiving the second (0.61; 95% CI 0.59-0.64) or third dose (0.63; 95% CI 0.62-0.64).

CONCLUSION

Our results showed that sick leave could be a relevant indicator for VE in the surveillance of COVID-19 and a finding that may be important in the surveillance of other respiratory infection.

Relative Effectiveness of the NVX-CoV2373 Vaccine Compared With the BNT162b2 Vaccine in Adolescents

This retrospective matched cohort study evaluated the efficacy of 2 doses of NVX-CoV2373 compared with that of BNT162b2 vaccines in preventing severe acute respiratory syndrome coronavirus 2 infection in adolescents. We analyzed 13-week risk differences and ratios between these 2 vaccines. The study included 465 NVX-CoV2373 and 465 BNT162b2 recipients. Throughout the follow-up period, 4.1% of NVX-CoV2373 recipients and 2.8% of BNT162b2 recipients contracted the severe acute respiratory syndrome coronavirus 2 infection. The incidence risk ratio for NVX-CoV2373 compared with that for BNT162b2 was calculated at 1.46 (95% CI 0.68-3.22; P = 0.296). While our findings suggest noninferiority between the 2 vaccines, further research is needed to comprehensively assess their effectiveness in real-world settings. Our study highlights the critical need for vigilant vaccine surveillance and monitoring efforts to ensure informed decision-making and public health protection.

Telemedical management of symptomatic COVID-19 outpatients

Background

COVID-19 remains a challenge to individual health and healthcare resources worldwide. Telemedical surveillance might minimise hospitalisation and direct patient-physician contacts. Yet, randomised clinical trials evaluating telemedical management of COVID-19 patients are lacking.

Methods

COVID-SMART is a randomised, open-label, controlled clinical trial investigating whether telemedicine reduces the primary end-point of hospitalisation or any unscheduled utilisation of an emergency medical service within 30 days of follow-up. Key secondary end-points included mortality and primary end-point components. We enrolled acutely infected SARS-CoV-2 patients suitable for outpatient care. All presented with ≥1 risk factor for an adverse COVID-19 course. Patients were randomised 1:1 into a control group receiving standard of care and an intervention group receiving smartphone-based assessment of oxygen saturation, heart rate and electrocardiogram, and telemedical counselling via a 24/7 emergency hotline.

Results

Of 607 enrolled patients (mean±sd age 46.7±13.5 years), 304 were randomised into the intervention and 303 into the control group. The primary end-point occurred in 6.9% (n=21) of the intervention and in 9.6% (n=29) of the control group (hazard ratio (HR) 0.72, 95% confidence interval (CI) 0.41-1.26; p=0.24). No deaths occurred during follow-up. Fewer intervention group participants utilised outpatient-based emergency medical services (HR 0.43, 95% CI 0.20-0.90; p=0.03).

Conclusions

COVID-SMART is the first randomised clinical trial assessing the benefit of telemedicine in an acute respiratory infectious disease. Whereas telemedical management did not reduce the primary end-point of hospitalisation, fewer intervention group patients used outpatient-based emergency services, suggesting a potential benefit for less-acutely infected individuals.

Efficacy and effectiveness of COVID-19 vaccines in Africa: A systematic review

BACKGROUND

Data on COVID-19 vaccine effectiveness to support regional vaccine policy and practice are limited in Africa. Thus, this review aimed to evaluate the efficacy and effectiveness of COVID-19 vaccines administered in Africa.

METHODS

We systematically searched peer-reviewed randomized controlled trials (RCTs), prospective and retrospective cohort studies, and case-control studies that reported on VE in Africa. We carried out a risk of bias assessment, and the findings of this review were synthesized and presented in a narrative form, including tables and figures. The synthesis was focused on COVID-19 VE against various levels of the disease condition and outcomes (infection, hospitalization or critical, and death), time points, and variants of concern.

RESULTS

A total of 13 studies, with a total sample size of 913,285 participants, were included in this review. The majority (8/13) of studies were from South Africa and 38.5% (5/13) were randomized clinical trials. The studies reported that a full dose of Pfizer-BioNTech vaccine had a VE of 100% against COVID-19 infection by Beta (B.1.351) and Delta variants and 96.7% against hospitalization by Delta variant. The Johnson and Johnson vaccine had VE ranging from 38.1%-62.0% against hospitalization and 51.9%- 86% against critical disease by Beta (B 1.351) variant. The Oxford-AstraZeneca vaccine had a VE of 89.4% against hospitalization by the Omicron variant but was not effective against the B.1.351 variant (10.4%). The Sinopharm vaccine had a VE of 67% against infection and 46% against hospitalization by Delta variant.

CONCLUSIONS

COVID-19 vaccines administered in Africa were effective in preventing infections, hospitalization, and death. These review findings underscore the need for concerted efforts of all stakeholders to enhance the access and availability of COVID-19 vaccines and reinforce public awareness to reach the high-risk, unvaccinated group of the African population.

Effectiveness of BNT162b2 Vaccine for Preventing COVID-19-Related Hospitalizations: A Test-Negative Case-Control Study

It is important to understand real-world BNT162b2 COVID-19 vaccine effectiveness (VE), especially among racial and ethnic minority groups. We performed a test-negative case-control study to measure BNT162b2 COVID-19 VE in the prevention of COVID-19-associated acute respiratory illness (ARI) hospitalizations at two Atlanta hospitals from May 2021-January 2023 and adjusted for potential confounders by multivariate analysis. Among 5139 eligible adults with ARI, 2763 (53.8%) were enrolled, and 1571 (64.5%) were included in the BNT162b2 analysis. The median age was 58 years (IQR, 44-68), 889 (56.6%) were female, 1034 (65.8%) were African American, 359 (22.9%) were White, 56 (3.6%) were Hispanic ethnicity, 645 (41.1%) were SARS-CoV-2-positive, 412 (26.2%) were vaccinated with a primary series, and 273 (17.4%) had received ≥1 booster of BNT162b2. The overall adjusted VE of the BNT162b2 primary series was 58.5% (95% CI 46.0, 68.1), while the adjusted VE of ≥1 booster was 78.9% (95% CI 70.0, 85.1). The adjusted overall VE of primary series for African American/Black individuals was 64.0% (95% CI 49.9, 74.1) and 82.7% (95% CI 71.9, 89.4) in those who received ≥1 booster. When analysis was limited to the period of Omicron predominance, overall VE of the primary series decreased with widened confidence intervals (24.5%, 95% CI -4.5, 45.4%), while VE of ≥1 booster was maintained at 60.9% (95% CI 42.0, 73.6). BNT162b2 primary series and booster vaccination provided protection against COVID-19-associated ARI hospitalization among a predominantly African American population.

Assessing the dynamics and impact of COVID-19 vaccination on disease spread: A data-driven approach

The COVID-19 pandemic has significantly impacted global health, social, and economic situations since its emergence in December 2019. The primary focus of this study is to propose a distinct vaccination policy and assess its impact on controlling COVID-19 transmission in Malaysia using a Bayesian data-driven approach, concentrating on the year 2021. We employ a compartmental Susceptible-Exposed-Infected-Recovered-Vaccinated (SEIRV) model, incorporating a time-varying transmission rate and a data-driven method for its estimation through an Exploratory Data Analysis (EDA) approach. While no vaccine guarantees total immunity against the disease, and vaccine immunity wanes over time, it is critical to include and accurately estimate vaccine efficacy, as well as a constant vaccine immunity decay or wane factor, to better simulate the dynamics of vaccine-induced protection over time. Based on the distribution and effectiveness of vaccines, we integrated a data-driven estimation of vaccine efficacy, calculated at 75% for Malaysia, underscoring the model's realism and relevance to the specific context of the country. The Bayesian inference framework is used to assimilate various data sources and account for underlying uncertainties in model parameters. The model is fitted to real-world data from Malaysia to analyze disease spread trends and evaluate the effectiveness of our proposed vaccination policy. Our findings reveal that this distinct vaccination policy, which emphasizes an accelerated vaccination rate during the initial stages of the program, is highly effective in mitigating the spread of COVID-19 and substantially reducing the pandemic peak and new infections. The study found that vaccinating 57-66% of the population (as opposed to 76% in the real data) with a better vaccination policy such as proposed here is able to significantly reduce the number of new infections and ultimately reduce the costs associated with new infections. The study contributes to the development of a robust and informative representation of COVID-19 transmission and vaccination, offering valuable insights for policymakers on the potential benefits and limitations of different vaccination policies, particularly highlighting the importance of a well-planned and efficient vaccination rollout strategy. While the methodology used in this study is specifically applied to national data from Malaysia, its successful application to local regions within Malaysia, such as Selangor and Johor, indicates its adaptability and potential for broader application. This demonstrates the model's adaptability for policy assessment and improvement across various demographic and epidemiological landscapes, implying its usefulness for similar datasets from various geographical regions.

Protective face mask: an effective weapon against SARS-CoV-2 with controlled environmental pollution

Masks are face coverings that give protection from infectious agents, airborne pathogens, bacteria, viruses, surgical fog, dust, and other chemical hazards by acting as a barrier between the wearer and the environment. In the COVID-19 pandemic, this major personal protective equipment's became essential part of our daily life. The aim of this review is to analyze and discuss the different types of masks with their pros and cons, manufacturing procedures, evaluation criteria, and application with some of the sterilization process for reuse and smart mask. The review used a thorough examination of the literature to analyze the preventive effects of surgical, N95, smart mask, and potential environmental damage from those masks. Several studies and evidence were also examined to understand the efficiency of different mask on different environment. N95 respirators are capable of filtering out non-oil-based 95% air-born particles, and surgical masks act as a protective barrier between the wearer and the environment. The application of spoon bond and melt blown techniques in the fabrication process of those masks improves their protective nature and makes them lightweight and comfortable. But the high demand and low supply forced users to reuse and extend their use after sterilizations, even though those masks are recommended to be used once. Universal masking in the SARS-COV-2 pandemic increased the chance of environmental pollution, so the application of smart masks became essential because of their high protection power and self-sterilizing and reusing capabilities.

Effective expression and characterization of the receptor binding domains in SARS-CoV-2 Spike proteins from original strain and variants of concern using Bombyx mori nucleopolyhedrovirus in silkworm

A new coronavirus, known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is responsible for the global pandemic of COVID-19 in 2020. Through structural analysis, it was found that several amino acid residues in the human angiotensin-converting enzyme-2 (hACE2) receptor directly interact with those in the receptor binding domain (RBD) of the spike glycoprotein (S-protein). Various cell lines, including HEK293, HeLa cells, and the baculovirus expression vector system (BEVS) with the insect cell line Sf9, have been utilized to produce the RBD. In this study, we investigated the use of Bombyx mori nucleopolyhedrovirus (BmNPV) and BEVS. For efficient production of a highly pure recombinant RBD protein, we designed it with two tags (His tag and STREP tag) at the C-terminus and a solubilizing tag (SUMO) at the N-terminus. After expressing the protein using BmNPV and silkworm and purifying it with a HisTrap excel column, the eluted protein was digested with SUMO protease and further purified using a Strep-Tactin Superflow column. As a result, we obtained the RBD as a monomer with a yield of 2.6 mg/10 mL serum (equivalent to 30 silkworms). The RBD showed an affinity for the hACE2 receptor. Additionally, the RBDs from the Alpha, Beta, Gamma, Delta, and Omicron variants were expressed and purified using the same protocol. It was found that the RBD from the Alpha, Beta, Gamma, and Delta variants could be obtained with yields of 1.4-2.6 mg/10 mL serum and had an affinity to the hACE2 receptor.

COVID-19 vaccine hesitancy prevalence in Mexico: A systematic review and metanalysis

Background

Vaccine hesitancy (VH) is a recognized threat to public health that undermines efforts to mitigate disease burden. This study aims to gather available evidence regarding COVID-19 VH in Mexico, estimate the prevalence of VH, and its determinants to inform policymaking in this country.

Methods

Following PRISMA guidelines, a systematic review of the MEDLINE literature, articles that estimated the prevalence of COVID-19 VH in Mexico were included in the analysis to obtain a pooled estimate. We used a binomial-normal model for meta-analysis of proportions (i.e., generalized linear mixed model) to perform the metanalysis. We then performed a narrative review of COVID-19 VH in Mexican subpopulations.

Results

Seven studies met inclusion criteria. We estimated a pooled prevalence of COVID-19 VH of 16 % (95 % CI: 11-23 %) in Mexico. We found an association between VH and demographic characteristics, intrinsic vaccine factors, and beliefs. Subgroup analyses from specific studies suggested that patients with clinical conditions such as breast cancer or rheumatologic diseases had a higher prevalence of VH.

Conclusions

VH is a highly complex and dynamic phenomenon in Mexico. Characterizing and understanding COVID-19 vaccine hesitancy in the Mexican population helps target future policy interventions to mitigate the spread and impact of infectious diseases. The implications of VH differ among groups that may be at higher risk of severe disease, underscoring the importance of prompt research among these groups as well as targeted interventions to address VH.

The COVID-19 Vaccine Hesitancy Among Healthcare Workers: An Exploration of Hesitancy Reasons and Suggestions to Improve Vaccination Rates

Objective

Vaccine hesitancy among healthcare workers (HCWs) represents a significant challenge and threat in pandemics. This study aims to identify the predictive factors influencing COVID-19 vaccine hesitancy among HCWs and offer strategies to increase the COVID-19 vaccination rate in healthcare settings.

Materials and Methods

This study constitutes the qualitative portion (second part) of a mixed-methods doctoral thesis employing an explanatory design. It was conducted in two distinct pandemic hospitals and involved 23 vaccine-hesitant HCWs. To conduct the interviews, the researchers developed a semi-structured interview form based on the Health Belief Model (HBM).

Results

Upon analyzing the in-depth interviews, we identified six primary reasons for vaccine hesitancy and four different sub-reasons that reinforce vaccine hesitancy. We also collected four key suggestions from vaccine-hesitant HCWs that could potentially persuade them to receive the COVID-19 vaccine.

Conclusion

This study's findings, which encompass the identification of reasons for COVID-19 vaccine hesitancy, clarification of underlying factors contributing to hesitancy towards the COVID-19 vaccines, and gathering suggestions from HCWs on how to persuade them to get vaccinated, hold significant value for guiding vaccination campaigns during potential future pandemics.

BBIBP-CorV vaccine effectiveness against COVID-19 in patients aged 60 years and older during the Delta-dominant period in the Federation of Bosnia and Herzegovina, a test-negative case-control study

COVID-19 vaccine uptake in the Federation of Bosnia and Herzegovina (FBiH) accelerated in the second half of 2021, with greater vaccine availability. In this study, we estimated the vaccine effectiveness (VE) of complete primary series BBIBP-CorV vaccine against COVID-19 in patients aged 60 years and older, during the Delta-dominant period, using a test-negative case-control design. Surveillance sites were 11 primary health care centers (PHC) collecting patient data from October 1, 2021, to January 4, 2022, retrospectively according to a common protocol. In total, we included 1711 participants in the analysis: 933 cases and 778 controls. Of the 933 cases, 508 (54.4 %) had mild and 425 (45.6 %) had moderate to severe disease presentation. We observed no effectiveness against mild COVID-19. Overall vaccine effectiveness was 65.0 % (95 %CI: 40.1-79.5) against moderate to severe COVID-19. In time since vaccination analysis, VE was 78.7 % (95 % CI: 54.8-89.9) in patients who received their last dose < 90 days before onset; 66.0 % (95 % CI: -0.5-88.5) in those 90-119 days before onset; 42.1 % (95 % CI: -88.6-82.3) in those 120-149 days before onset and 45.0 % (95 % CI: -94.0-84.4) in those ≥ 150 days before onset. In our study, two doses of BBIBP-CorV provided considerable protection against moderate to severe COVID-19 in older adults, highest within 3 months after second dose, during the Delta-dominant period. Point estimates declined thereafter, suggesting a need for additional doses.

COVID-19 Variants and Vaccine Development

Coronavirus disease 2019 (COVID-19), the global pandemic caused by severe acute respiratory syndrome 2 virus (SARS-CoV-2) infection, has caused millions of infections and fatalities worldwide. Extensive SARS-CoV-2 research has been conducted to develop therapeutic drugs and prophylactic vaccines, and even though some drugs have been approved to treat SARS-CoV-2 infection, treatment efficacy remains limited. Therefore, preventive vaccination has been implemented on a global scale and represents the primary approach to combat the COVID-19 pandemic. Approved vaccines vary in composition, although vaccine design has been based on either the key viral structural (spike) protein or viral components carrying this protein. Therefore, mutations of the virus, particularly mutations in the S protein, severely compromise the effectiveness of current vaccines and the ability to control COVID-19 infection. This review begins by describing the SARS-CoV-2 viral composition, the mechanism of infection, the role of angiotensin-converting enzyme 2, the host defence responses against infection and the most common vaccine designs. Next, this review summarizes the common mutations of SARS-CoV-2 and how these mutations change viral properties, confer immune escape and influence vaccine efficacy. Finally, this review discusses global strategies that have been employed to mitigate the decreases in vaccine efficacy encountered against new variants.

Vaccine effectiveness against emerging COVID-19 variants using digital health data

BACKGROUND

Participatory surveillance of self-reported symptoms and vaccination status can be used to supplement traditional public health surveillance and provide insights into vaccine effectiveness and changes in the symptoms produced by an infectious disease. The University of Maryland COVID Trends and Impact Survey provides an example of participatory surveillance that leveraged Facebook's active user base to provide self-reported symptom and vaccination data in near real-time.

METHODS

Here, we develop a methodology for identifying changes in vaccine effectiveness and COVID-19 symptomatology using the University of Maryland COVID Trends and Impact Survey data from three middle-income countries (Guatemala, Mexico, and South Africa). We implement conditional logistic regression to develop estimates of vaccine effectiveness conditioned on the prevalence of various definitions of self-reported COVID-like illness in lieu of confirmed diagnostic test results.

RESULTS

We highlight a reduction in vaccine effectiveness during Omicron-dominated waves of infections when compared to periods dominated by the Delta variant (median change across COVID-like illness definitions: -0.40, IQR[-0.45, -0.35]. Further, we identify a shift in COVID-19 symptomatology towards upper respiratory type symptoms (i.e., cough and sore throat) during Omicron periods of infections. Stratifying COVID-like illness by the National Institutes of Health's (NIH) description of mild and severe COVID-19 symptoms reveals a similar level of vaccine protection across different levels of COVID-19 severity during the Omicron period.

CONCLUSIONS

Participatory surveillance data alongside methodologies described in this study are particularly useful for resource-constrained settings where diagnostic testing results may be delayed or limited.

Effectiveness of BNT162b2 Vaccine Against Symptomatic SARS-CoV-2 Infection in Children Aged 5-11 Years in Japan During Omicron Variant Predominate Periods

BACKGROUND

Although the effectiveness of BNT162b2 messenger RNA vaccines against the Omicron variant has been reported in several countries, data are limited in children living in Asian countries. Therefore, this study aimed to estimate the effectiveness of the pediatric primary two-dose monovalent mRNA vaccine series in preventing symptomatic novel coronavirus disease 2019 (COVID-19) in Japan.

METHODS

We conducted a test-negative case-control study (262 test-positive cases and 259 test-negative controls) in patients aged 5-11 years who presented with COVID-19-like symptoms during the Omicron BA.2- and BA.5-predominant periods. Vaccination status, demographic data, underlying medical conditions, lifestyle, personal protective health behaviors, living environment, and PCR test results were obtained using parent-administered questionnaires and clinical records. Vaccine effectiveness (VE) against symptomatic COVID-19 was calculated using a multivariate logistic regression analysis.

RESULTS

Of the test-positive cases and test-negative controls, 9.2% (n = 24) and 12.7% (n = 33) received two vaccine doses, respectively. Having siblings and a BA.5-dominant period were significantly associated with symptomatic COVID-19. After adjusting for age, siblings, study period, and duration after the last vaccination, the overall VE of two-dose vaccination was 50.0% (95% confidence interval [CI], 5-74%). VE was 72% (95% CI, 24-89%) within 3 months after the two-dose vaccination, while it decreased to 24% (95% CI, -80% to 68%) after 3 months.

CONCLUSION

Two BNT162b messenger RNA vaccine doses provided moderate protection against symptomatic COVID-19 during the Omicron variant period. A time-dependent decrease in VE was noted after the second dose; thus, a booster dose 3 months after the second dose is warranted.

Immunogenicity, Effectiveness, and Safety of COVID-19 Vaccines among Patients with Immune-Mediated Dermatological Diseases: A Systematic Review and Meta-analysis

Immunocompromised individuals, primarily attributable to using immunosuppressants, face heightened COVID-19 risks. Despite the proven efficacy of COVID-19 vaccines, their impact on patients with immune-mediated dermatological diseases remains unclear. This study aims to thoroughly examine vaccine immunogenicity, effectiveness, and safety in immune-mediated dermatological disease patients. Clinical studies in adults that compared vaccinated immune-mediated dermatological disease patients with vaccinated healthy controls or unvaccinated immune-mediated dermatological disease patients in terms of vaccine immunogenicity, COVID-19 infection, adverse events, or exacerbation of immune-mediated dermatological diseases were searched via electronic databases. Seventeen studies (1,348,690 participants) were included. Seroconversion rates between immune-mediated dermatological disease patients and healthy controls were not different. However, among individuals aged ≤55 years, immune-mediated dermatological disease patients had lower mean anti-SARS-CoV-2 IgG levels. Immunosuppressed immune-mediated dermatological disease patients also had lower titres and were less likely to achieve T-cell response. In terms of safety, the risk of adverse events was higher in atopic dermatitis patients, but those with psoriasis had a reduced risk. Additionally, immunosuppressed patients had fewer adverse events. Vaccinated immune-mediated dermatological disease patients had a lower risk of COVID-19 infection than unvaccinated patients but a higher risk than healthy controls; however, disease exacerbation may be induced. In conclusion, immune-mediated dermatological diseases showed a reduced vaccine response in our meta-analysis, yet vaccination remained effective against COVID-19 infection and well tolerated.

Indirect vaccine effectiveness in an outbreak of Alpha B.1.1.7 variant in a California state Prison, May 2021

Incarcerated populations experienced high rates of SARS-CoV-2 infection and death during early phases of the COVID-19 pandemic. To evaluate vaccine effectiveness in the carceral context, we investigated the first outbreak of COVID-19 in a California state prison following widespread rollout of vaccines to residents in early 2021. We identified a cohort of 733 state prison residents presumed to be exposed between May 14 and June 22, 2021. 46.9 % (n = 344) were vaccinated, primarily with two doses of mRNA-1273 (n = 332, 93.6 %). In total, 92 PCR-positive cases were identified, of which 14 (14.5 %) occurred among mRNA-1273 vaccinated residents. No cases required hospitalization. All nine isolates collected belonged to the Alpha (B.1.1.7) variant. We used Cox proportional hazard regression to estimate vaccine effectiveness for at least one dose of any vaccine at the start of the outbreak. Vaccine effectiveness was 86 % (95 % CI: 75 %-97 %) against PCR-confirmed infection, with similar results for symptomatic infection. Higher rates of building-level vaccine uptake were associated with a lower overall rate of PCR-confirmed infection and symptomatic infection among unvaccinated residents. Among unvaccinated residents who lived in shared cells at the time of presumed exposure, exposure to a vaccinated cellmate was associated with a 38% (95% CI: 0.37, 1.04) lower hazard rate of PCR-confirmed infection over the study period. In this outbreak involving the Alpha SARS-CoV-2 variant, vaccination conferred direct and possibly indirect protection against SARS-CoV-2 infection and symptomatic COVID-19. Our results support the importance of vaccine uptake in mitigating outbreaks and severe disease in the prison setting and the consideration of community vaccination levels in policy and infection response.

Clinical outcomes and risk factors for SARS-CoV-2 breakthrough cases following vaccination with BNT162b2, CoronaVac, or ChAdOx1-S: A retrospective cohort study in Malaysia

Background

The SARS-CoV-2 pandemic drove global vaccination. However, breakthrough infections raised concerns about vaccine performance, leading the World Health Organization (WHO) to recommend investigations thereof. This study aimed to evaluate the clinical outcomes (time to breakthrough infection, intensive care unit [ICU] admission, and in-hospital mortality) of hospitalised patients with SARS-CoV-2 breakthrough infection. This was the primary outcome and the risk factors associated with its severity were the secondary outcomes.

Methods

This retrospective cohort study at a multispecialty tertiary hospital in Selangor, Malaysia included 200 fully adult vaccinated patients, with confirmed SARS-CoV-2 infection, admitted from September 2021 to February 2022. Participants were selected by simple random sampling. Infection severity was categorised as CAT 2-3 (mild-moderate) and 4-5 (severe-critical).

Results

The time to breakthrough infection was significantly longer for BNT162B2 recipients (128.47 ± 46.21 days) compared to CoronaVac (94.09 ± 48.71 days; P = 0.001) and ChAdOx1-S recipients (90.80 ± 37.59 days; P = 0.019). No significant associations were found between SARS-CoV-2-related ICU admission, mortality, and the vaccines. Multivariable analysis identified vaccine type, variant of concern, ethnicity, and hypertension as significant predictors of severity. BNT162b2 and ChAdOx1-S recipients had significantly (81 % and 74 %, respectively) lower odds of CAT 4-5 infection compared to CoronaVac recipients. Indian patients had a significantly (83 %) lower chance of CAT 4-5 infection compared to Malay patients. Patients with breakthrough infections during the Omicron period had a significantly (58 %) lower risk of CAT 4-5 compared to those in the Delta period. The CAT 4-5 risk was significantly (nearly threefold) higher in hypertensive patients.

Conclusion

The results support the Malaysian Ministry of Health's recommended booster three months after primary vaccination and the WHO's recommended heterologous booster following CoronaVac. Certain ethnic groups, hypertensive patients, and viral variants may require attention in future pandemics.

Lessons we learned during the past four challenging years in the COVID-19 era: pharmacotherapy, long COVID complications, and vaccine development

About four years have passed since the detection of the first cases of COVID-19 in China. During this lethal pandemic, millions of people have lost their lives around the world. Since the first waves of COVID-19 infection, various pharmacotherapeutic agents have been examined in the management of COVID-19. Despite all these efforts in pharmacotherapy, drug repurposing, and design and development of new drugs, multiple organ involvement and various complications occurred during COVID-19. Some of these complications became chronic and long-lasting which led to the "long COVID" syndrome appearance. Therefore, the best way to eradicate this pandemic is prophylaxis through mass vaccination. In this regard, various vaccine platforms including inactivated vaccines, nucleic acid-based vaccines (mRNA and DNA vaccines), adenovirus-vectored vaccines, and protein-based subunit vaccines have been designed and developed to prevent or reduce COVID-19 infection, hospitalization, and mortality rates. In this focused review, at first, the most commonly reported clinical presentations of COVID-19 during these four years have been summarized. In addition, different therapeutic regimens and their latest status in COVID-19 management have been listed. Furthermore, the "long COVID" and related signs, symptoms, and complications have been mentioned. At the end, the effectiveness of available COVID-19 vaccines with different platforms against early SARS-CoV-2 variants and currently circulating variants of interest (VOI) and the necessity of booster vaccine shots have been summarized and discussed in more detail.

Real life experience on the use of Remdesivir in patients admitted to COVID-19 in two referral Italian hospital: a propensity score matched analysis

Remdesivir (RDV) was the first Food and Drug Administration (FDA)-approved medication for COVID-19, with discordant data on efficacy in reducing mortality risk and disease progression. In the context of a dynamic and rapidly changing pandemic landscape, the utilization of real-world evidence is of utmost importance. The objective of this study is to evaluate the impact of RDV on patients who have been admitted to two university referral hospitals in Italy due to COVID-19. All patients older than 18 years and hospitalized at two different universities (Bari and Palermo) were enrolled in this study. To minimize the effect of potential confounders, we used propensity score matching with one case (Remdesivir) and one control that never experienced this kind of intervention during hospitalization. Mortality was the primary outcome of our investigation, and it was recorded using death certificates and/or medical records. Severe COVID-19 was defined as admission to the intensive care unit or a qSOFAscore ≥ 2 or CURB65scores ≥ 3. After using propensity score matching, 365 patients taking Remdesivir and 365 controls were included. No significant differences emerged between the two groups in terms of mean age and percentage of females, while patients taking Remdesivir were less frequently active smokers (p < 0.0001). Moreover, the patients taking Remdesivir were less frequently vaccinated against COVID-19. All the other clinical, radiological, and pharmacological parameters were balanced between the two groups. The use of Remdesivir in our cohort was associated with a significantly lower risk of mortality during the follow-up period (HR 0.56; 95% CI 0.37-0.86; p = 0.007). Moreover, RDV was associated with a significantly lower incidence of non-invasive ventilation (OR 0.27; 95% CI 0.20-0.36). Furthermore, in the 365 patients taking Remdesivir, we observed two cases of mild renal failure requiring a reduction in the dosage of Remdesivir and two cases in which the physicians decided to interrupt Remdesivir for bradycardia and for QT elongation. Our study suggests that the use of Remdesivir in hospitalized COVID-19 patients is a safe therapy associated with improved clinical outcomes, including halving of mortality and with a reduction of around 75% of the risk of invasive ventilation. In a constantly changing COVID-19 scenario, ongoing research is necessary to tailor treatment decisions based on the latest scientific evidence and optimize patient outcomes.

Natural Killer Cells Do Not Attenuate a Mouse-Adapted SARS-CoV-2-Induced Disease in Rag2-/- Mice

This study investigates the roles of T, B, and Natural Killer (NK) cells in the pathogenesis of severe COVID-19, utilizing mouse-adapted SARS-CoV-2-MA30 (MA30). To evaluate this MA30 mouse model, we characterized MA30-infected C57BL/6 mice (B6) and compared them with SARS-CoV-2-WA1 (an original SARS-CoV-2 strain) infected K18-human ACE2 (K18-hACE2) mice. We found that the infected B6 mice developed severe peribronchial inflammation and rapid severe pulmonary edema, but less lung interstitial inflammation than the infected K18-hACE2 mice. These pathological findings recapitulate some pathological changes seen in severe COVID-19 patients. Using this MA30-infected mouse model, we further demonstrate that T and/or B cells are essential in mounting an effective immune response against SARS-CoV-2. This was evident as Rag2-/- showed heightened vulnerability to infection and inhibited viral clearance. Conversely, the depletion of NK cells did not significantly alter the disease course in Rag2-/- mice, underscoring the minimal role of NK cells in the acute phase of MA30-induced disease. Together, our results indicate that T and/or B cells, but not NK cells, mitigate MA30-induced disease in mice and the infected mouse model can be used for dissecting the pathogenesis and immunology of severe COVID-19.

Estimating All-Cause Deaths Averted in the First Two Years of the COVID-19 Vaccination Campaign in Italy

Comparing deaths averted by vaccination campaigns is a crucial public health endeavour. Excess all-cause deaths better reflect the impact of the pandemic than COVID-19 deaths. We used a seasonal autoregressive integrated moving average with exogenous factors model to regress daily all-cause deaths on annual trend, seasonality, and environmental temperature in three Italian regions (Lombardy, Marche and Sicily) from 2015 to 2019. The model was used to forecast excess deaths during the vaccinal period (December 2020-October 2022). We used the prevented fraction to estimate excess deaths observed during the vaccinal campaigns, those which would have occurred without vaccination, and those averted by the campaigns. At the end of the vaccinal period, the Lombardy region proceeded with a more intensive COVID-19 vaccination campaign than other regions (on average, 1.82 doses per resident, versus 1.67 and 1.56 in Marche and Sicily, respectively). A higher prevented fraction of all-cause deaths was consistently found in Lombardy (65% avoided deaths, as opposed to 60% and 58% in Marche and Sicily). Nevertheless, because of a lower excess mortality rate found in Lombardy compared to Marche and Sicily (12, 24 and 23 per 10,000 person-years, respectively), a lower rate of averted deaths was observed (22 avoided deaths per 10,000 person-years, versus 36 and 32 in Marche and Sicily). In Lombardy, early and full implementation of adult COVID-19 vaccination was associated with the largest reduction in all-cause deaths compared to Marche and Sicily.

Long COVID and its association with neurodegenerative diseases: pathogenesis, neuroimaging, and treatment

Corona Virus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has presented unprecedented challenges to the world. Changes after acute COVID-19 have had a significant impact on patients with neurodegenerative diseases. This study aims to explore the mechanism of neurodegenerative diseases by examining the main pathways of central nervous system infection of SARS-CoV-2. Research has indicated that chronic inflammation and abnormal immune response are the primary factors leading to neuronal damage and long-term consequences of COVID-19. In some COVID-19 patients, the concurrent inflammatory response leads to increased release of pro-inflammatory cytokines, which may significantly impact the prognosis. Molecular imaging can accurately assess the severity of neurodegenerative diseases in patients with COVID-19 after the acute phase. Furthermore, the use of FDG-PET is advocated to quantify the relationship between neuroinflammation and psychiatric and cognitive symptoms in patients who have recovered from COVID-19. Future development should focus on aggressive post-infection control of inflammation and the development of targeted therapies that target ACE2 receptors, ERK1/2, and Ca2+.

The prevalence of Human Immunodeficiency Virus infection among voluntary blood donors in mainland China: A systematic review and meta-analysis

Human immunodeficiency virus (HIV) infection through transfusion has been an imperative challenge for blood safety. Despite the implementation of screening strategies, there was still the residual risk of transfusion-transmitted HIV. Considering that the prevalence of HIV infection in blood donors is significant for evaluating blood safety and potential risks to the population, meta-analysis was applied to investigate the HIV prevalence among voluntary blood donors during the past 27 years to characterize the epidemiology and related risk factors of HIV in blood donors. The literature concerning the HIV screening reactive rate and prevalence in Chinese voluntary blood donors was collected through the systematic searching of four electronic databases. After integrating data, following the Preferred Reporting of Items for Systematic Reviews and Meta-Analyses guidelines, data manipulation and statistical analyses were conducted by Stata 12.0. The results indicated that overall HIV prevalence was 0.0178% (95% confidence interval [CI], 0.0169%-0.0187%) with a remarkable rise, which varied from 2000 (0.0034%) to 2015 (0.027%). The HIV window period infection rate was 0.0475‱ (95% CI, 0.0304‱-0.0646‱). Importantly, subgroup analysis revealed the heterogeneity in gender, occupations, education and donation frequency. With the effective control of HIV transmission through blood, HIV prevalence declined in China to some extent in recent years, and the characteristics of HIV epidemic in some provinces have drastically changed. However, remaining relatively high HIV prevalence and overall increased trend of HIV prevalence since the 21th century demonstrates the potential residual risk of blood transfusion, and the whole society is supposed to pay close attention to HIV infection.

Risk of SARS-CoV-2 breakthrough infection following NVX-CoV2373 and BNT162b2 vaccinations in Korean Adults: A population-based observational study

South Korea experienced a low prevalence of SARS-CoV-2 until the emergence of the omicron in early 2022, triggering a major community epidemic. To evaluate effectiveness of NVX-CoV2373 and BNT162b2 vaccines in Korean population, we conducted an observational study utilizing individual-level case data on laboratory-confirmed SARS-CoV-2 infection, along with vaccination record. A total of 47,078 recipients of NVX-CoV2373 vaccine and 7,561 recipients of BNT162b2 vaccine were eligible for the study. Thirty days post-second doses, COVID-19 rates were 7.9% (595 out of 7561) of NVX-CoV2373 recipients and 8.6 % (647 out of 7561) of BNT162b2 recipients experienced COVID-19. NVX-CoV2373 rates increased to 9.8 % and 11.2 % at 60 and 90 days, while BNT162b2 rates were 10.5 % and 11.3 % at the same intervals. The 22-weeks risk ratios for recipients of the NVX-CoV2373 vaccine as compared with recipients of the BNT162b2 vaccine were 1.11 (95 % CI, 0.99 to 1.25) for laboratory-confirmed SARS-CoV-2 infection. Continued monitoring is essential to evaluate the duration of protection across different vaccine platforms and schedules.

Trends in primary, booster, and updated COVID-19 vaccine readiness in the United States, January 2021-April 2023: Implications for 2023-2024 updated COVID-19 vaccines

OBJECTIVE

COVID-19 vaccines have mitigated the severity of COVID-19 and its sequelae. The emergence of new SARS-CoV-2 variants and waning immunity conferred by COVID-19 vaccination have necessitated booster and updated COVID-19 vaccines. This study examined trends in vaccine readiness-a composite measure of intention and uptake-for the primary, booster, and 2022-2023 updated (bivalent) COVID-19 vaccines among U.S. adults.

METHODS

Data from the nationally-representative U.S. Department of Health and Human Services' COVID-19 Monthly Outcome Survey from January 2021 to April 2023 were analyzed (N = 140,180). We conducted pairwise comparisons (weighted t-tests) to assess for significant between-month differences in the proportion of participants in each vaccine-readiness category (vaccine ready, wait and see, and no vaccine intention) for the following outcomes: (1) primary; (2) booster; and (3) updated COVID-19 vaccine readiness.

RESULTS

From January 2021 to April 2023, significant increases in the primary vaccine ready group were accompanied by decreases in the wait and see and no vaccine intention groups (p < 0.001). From January to September 2022, the no booster intention group notably increased (p < 0.001), whereas the booster ready group decreased (p < 0.001), and the wait and see group remained stable (p = 0.116). From October 2022 to April 2023, the no updated vaccine intention group increased (p < 0.001), the wait and see group decreased (p < 0.01), and the updated vaccine ready group remained unchanged (p = 0.357).

CONCLUSIONS

Findings show decreased vaccine readiness for the booster and 2022-2023 updated (bivalent) COVID-19 vaccines relative to the primary COVID-19 vaccines. Implications for the 2023-2024 updated COVID-19 vaccines are discussed.

COVID-19 cooling: Nanostrategies targeting cytokine storm for controlling severe and critical symptoms

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants continue to wreak havoc worldwide, the "Cytokine Storm" (CS, also known as the inflammatory storm) or Cytokine Release Syndrome has reemerged in the public consciousness. CS is a significant contributor to the deterioration of infected individuals. Therefore, CS control is of great significance for the treatment of critically ill patients and the reduction of mortality rates. With the occurrence of variants, concerns regarding the efficacy of vaccines and antiviral drugs with a broad spectrum have grown. We should make an effort to modernize treatment strategies to address the challenges posed by mutations. Thus, in addition to the requirement for additional clinical data to monitor the long-term effects of vaccines and broad-spectrum antiviral drugs, we can use CS as an entry point and therapeutic target to alleviate the severity of the disease in patients. To effectively combat the mutation, new technologies for neutralizing or controlling CS must be developed. In recent years, nanotechnology has been widely applied in the biomedical field, opening up a plethora of opportunities for CS. Here, we put forward the view of cytokine storm as a therapeutic target can be used to treat critically ill patients by expounding the relationship between coronavirus disease 2019 (COVID-19) and CS and the mechanisms associated with CS. We pay special attention to the representative strategies of nanomaterials in current neutral and CS research, as well as their potential chemical design and principles. We hope that the nanostrategies described in this review provide attractive treatment options for severe and critical COVID-19 caused by CS.

A semi-quantitative visual lateral flow immunoassay for SARS-CoV-2 antibody detection for the follow-up of immune response to vaccination or recovery

The lateral flow immunoassay (LFIA) technique is largely employed for the point-of-care detection of antibodies especially for revealing the immune response in serum. Visual LFIAs usually provide the qualitative yes/no detection of antibodies, while quantification requires some equipment, making the assay more expensive and complicated. To achieve visual semi-quantification, the alignment of several lines (made of the same antigen) along a LFIA strip has been proposed. The numbering of the reacting lines has been used to correlate with the quantity of some biomarkers in serum. Here, we designed the first semiquantitative LFIA for detecting antibodies and applied it to classify the immune response to SARS-CoV-2 raised by vaccination or natural infection. We used a recombinant spike receptor-binding domain (RBD) as the specific capture reagent to draw two test lines. The detection reagent was selected among three possible ligands that are able to bind to anti-spike human antibodies: the same RBD, staphylococcal protein A, and anti-human immunoglobulin G antibodies. The most convenient detector, adsorbed on gold nanoparticles, was chosen based on the highest correlation with an antibody titre of 171 human sera, measured by a reference serological method, and was the RBD (Spearman's rho = 0.84). Incorporated into the semiquantitative LFIA, it confirmed the ability to discriminate high- and low-titre samples and to classify them into two classes (Dunn's test, P < 0.05). The proposed approach enabled the semiquantification of the immune response to SARS-CoV-2 by the unaided eye observation, thus overcoming the requirement of costly and complicated equipment, and represents a general strategy for the development of semiquantitative serological LFIAs.

Immunogenicity of Tetravalent Protein Vaccine SCTV01E-2 against SARS-CoV-2 EG.5 Subvaraint: A Phase 2 Trial

The Omicron EG.5 lineage of SARS-CoV-2 is currently on a trajectory to become the dominant strain. This phase 2 study aims to evaluate the immunogenicity of SCTV01E-2, a tetravalent protein vaccine, with a specific emphasis on its immunogenicity against Omicron EG.5, comparing it with its progenitor vaccine, SCTV01E (NCT05933512). As of 12 September 2023, 429 participants aged ≥18 years were randomized into the groups SCTV01E (N = 215) and SCTV01E-2 (N = 214). Both vaccines showed increases in neutralizing antibody (nAb) against Omicron EG.5, with a 5.7-fold increase and a 9.0-fold increase in the SCTV01E and SCTV01E-2 groups 14 days post-vaccination, respectively. The predetermined statistical endpoints were achieved, showing that the geometric mean titer (GMT) of nAb and the seroresponse rate (SRR) against Omicron EG.5 were significantly higher in the SCTV01E-2 group than in the SCTV01E group. Additionally, SCTV01E and SCTV01E-2 induced a 5.5-fold and a 5.9-fold increase in nAb against XBB.1, respectively. Reactogenicity was generally mild and transient. No vaccine-related serious adverse events (SAEs), adverse events of special interest (AESIs), or deaths were reported. In summary, SCTV01E-2 elicited robust neutralizing responses against Omicron EG.5 and XBB.1 without raising safety concerns, highlighting its potential as a versatile COVID-19 vaccine against SARS-CoV-2 variants.

Real-world effectiveness of the inactivated COVID-19 vaccines against variant of concerns: meta-analysis

BACKGROUND

COVID-19 has killed over 6 million people worldwide, making it the worst global health disaster since the 1918 influenza pandemic. Experts have worked to establish the source, track and analyse the disease, and produce treatment and preventative guidelines. Inactivated vaccines have little evidence of efficacy compared to mRNA and adenoviral vector vaccines; however, three doses of both mRNA and inactivated vaccines appear to provide significant and lasting protection against severe disease and mortality. This study examines inactivated vaccine effectiveness data by disease status, age, gender, primary immunisation, booster doses, and SARS-CoV2 virus types.

METHODS

We conducted a quantitative epidemiological meta-analysis study to assess the vaccine effectiveness of inactivated COVID-19 vaccines. Data extraction was performed on the selected studies, and data analysis was conducted using a random-effects model to determine consolidated assessments of vaccine effectiveness. Subgroup analyses were conducted for gender, age, disease level, and vaccine status, and sensitivity analyses were conducted to assess the robustness of the results.

RESULTS

The overall effect size of inactivated COVID-19 vaccinations was statistically significant (p-value<0.05), suggesting that complete vaccination should be the primary method of vaccination. Partial vaccination was associated with lower levels of vaccine effectiveness (70.18 95% CI 57.33-83.02) than complete vaccination (79.52 95% CI 67.88-91.71)) and booster vaccination (84.22 95% CI 74.34-94.10), suggesting that it is essential to finish the recommended vaccine series and receive booster doses. Fig.-3: Partially vaccinated individuals showed a vaccine effect size of 70.18 (95% CI 57.33-83.02), indicating that the vaccine was moderately effective in preventing COVID-19 among this group. Fully vaccinated individuals showed a vaccine effect size of 79.52 (95% CI 67.88-91.71), indicating a higher level of vaccine effectiveness. Finally, booster-vaccinated individuals showed a vaccine effect size of 84.22 (95% CI 74.34-94.10), indicating the highest level of vaccine effectiveness.

CONCLUSION

Inactivated COVID-19 vaccines are highly effective in preventing COVID-19, and complete vaccination and booster vaccination are associated with higher levels of vaccine effectiveness compared to partial vaccination. These findings highlight the importance of completing the recommended vaccine series and receiving booster doses to provide greater protection against COVID-19.

B-cell and antibody responses to SARS-CoV-2: infection, vaccination, and hybrid immunity

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2019 prompted scientific, medical, and biotech communities to investigate infection- and vaccine-induced immune responses in the context of this pathogen. B-cell and antibody responses are at the center of these investigations, as neutralizing antibodies (nAbs) are an important correlate of protection (COP) from infection and the primary target of SARS-CoV-2 vaccine modalities. In addition to absolute levels, nAb longevity, neutralization breadth, immunoglobulin isotype and subtype composition, and presence at mucosal sites have become important topics for scientists and health policy makers. The recent pandemic was and still is a unique setting in which to study de novo and memory B-cell (MBC) and antibody responses in the dynamic interplay of infection- and vaccine-induced immunity. It also provided an opportunity to explore new vaccine platforms, such as mRNA or adenoviral vector vaccines, in unprecedented cohort sizes. Combined with the technological advances of recent years, this situation has provided detailed mechanistic insights into the development of B-cell and antibody responses but also revealed some unexpected findings. In this review, we summarize the key findings of the last 2.5 years regarding infection- and vaccine-induced B-cell immunity, which we believe are of significant value not only in the context of SARS-CoV-2 but also for future vaccination approaches in endemic and pandemic settings.

COVID-19 Vaccines: Where Did We Stand at the End of 2023?

Vaccine development against SARS-CoV-2 has been highly successful in slowing down the COVID-19 pandemic. A wide spectrum of approaches including vaccines based on whole viruses, protein subunits and peptides, viral vectors, and nucleic acids has been developed in parallel. For all types of COVID-19 vaccines, good safety and efficacy have been obtained in both preclinical animal studies and in clinical trials in humans. Moreover, emergency use authorization has been granted for the major types of COVID-19 vaccines. Although high safety has been demonstrated, rare cases of severe adverse events have been detected after global mass vaccinations. Emerging SARS-CoV-2 variants possessing enhanced infectivity have affected vaccine protection efficacy requiring re-design and re-engineering of novel COVID-19 vaccine candidates. Furthermore, insight is given into preparedness against emerging SARS-CoV-2 variants.

Transmission characteristics and inactivated vaccine effectiveness against transmission of the SARS-CoV-2 Omicron BA.2 variant in Shenzhen, China

We conducted a retrospective cohort study to evaluate the transmission risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron BA.2 variant and the effectiveness of inactivated COVID-19 vaccine boosters in Shenzhen during a BA.2 outbreak period from 1 February to 21 April 2022. A total of 1,248 individuals were infected with the BA.2 variant, and 7,855 close contacts were carefully investigated. The risk factors for the high secondary attack rate of SARS-CoV-2 infection were household contacts [adjusted odds ratio (aOR): 1.748; 95% confidence interval (CI): 1.448, 2.110], younger individuals aged 0-17 years (aOR: 2.730; 95% CI: 2.118, 3.518), older persons aged ≥60 years (aOR: 1.342; 95% CI: 1.135, 1.588), women (aOR: 1.442; 95% CI: 1.210, 1.718), and the subjects exposed to the post-onset index cases (aOR: 8.546; 95% CI: 6.610, 11.050), respectively. Compared with the unvaccinated and partially vaccinated individuals, a relatively low risk of secondary attack was found for the individuals who received booster vaccination (aOR: 0.871; 95% CI: 0.761, 0.997). Moreover, a high transmission risk was found for the index cases aged ≥60 years (aOR: 1.359; 95% CI: 1.132, 1.632), whereas a relatively low transmission risk was observed for the index cases who received full vaccination (aOR: 0.642; 95% CI: 0.490, 0.841) and booster vaccination (aOR: 0.676; 95% CI: 0.594, 0.770). Compared with full vaccination, booster vaccination of inactivated COVID-19 vaccine showed an effectiveness of 24.0% (95% CI: 7.0%, 37.9%) against BA.2 transmission for the adults ≥18 years and 93.7% (95% CI: 72.4%, 98.6%) for the adults ≥60 years, whereas the effectiveness was 51.0% (95% CI: 21.9%, 69.3%) for the individuals of 14 days to 179 days after booster vaccination and 51.2% (95% CI: 37.5%, 61.9%) for the non-household contacts. The estimated mean values of the generation interval, serial interval, incubation period, latent period, and viral shedding period were 2.7 days, 3.2 days, 2.4 days, 2.1 days, and 17.9 days, respectively. In summary, our results confirmed that the main transmission route of Omicron BA.2 subvariant was household contact, and booster vaccination of the inactivated vaccines was relatively effective against BA.2 subvariant transmission in older people.

COVID-19 outcome trends by vaccination status in Canada, December 2020-January 2022

Background

The coronavirus disease 2019 (COVID-19) pandemic in Canada has evolved rapidly. Since late 2020, COVID-19 vaccines have been relied on to protect against severe outcomes in the presence of circulating variants of concern (VOC).

Objective

This surveillance report provides a retrospective descriptive analysis of national trends in COVID-19 cases and severe outcomes by vaccination status, contextualizing trends against case demographics and circulating VOCs, from December 2020 to January 2022.

Methods

Case and vaccination coverage surveillance data were obtained from the National COVID-19 Case Dataset and the Canadian COVID-19 Vaccination Coverage Surveillance System for 12 of 13 provinces and territories. Descriptive analyses were produced to describe trends over time among individuals aged 12 years and older by COVID-19 outcome, vaccination status, and demographics. Age-standardized and age-stratified incidence rates and incidence rate ratios were computed for cases, hospitalizations, and deaths.

Results

From mid to late-2021, incidence rates for cases and severe outcomes were consistently lowest among those with a completed primary series and highest among those who were unvaccinated. Unvaccinated individuals were much more likely to be hospitalized or to die compared to those with a completed primary series in all variant periods. Age-specific rates of severe outcomes were consistently highest among those aged 80 years and older across all vaccination statuses.

Conclusion

Vaccination remains one of the most important public health interventions, particularly among older adults, to protect against COVID-19 severe outcomes as the pandemic evolves. Routine monitoring of COVID-19 outcomes by vaccination status can identify changes in COVID-19 epidemiology and inform public health action and policy.

Risk of severe COVID-19 in unvaccinated patients during the period from wild-type to Omicron variant: real-world evidence from Japan

BACKGROUND

Many studies have reported that the Omicron variant is less pathogenic than the Delta variant and the wild-type. Epidemiological evidence regarding the risk of severe COVID-19 from the wild-type to the Omicron variant has been lacking.

METHODS

Study participants were COVID-19 patients aged 18 and older without previous COVID-19 infection who were notified to the Nara Prefecture Chuwa Public Health Center from January 2020 to March 2023, during the periods from the wild-type to the Omicron variant. The outcome variable was severe COVID-19 (i.e., ICU admission or COVID-19-related death). The explanatory variable was SARS-CoV-2 variant type or the number of COVID-19 vaccinations. Covariates included gender, age, risk factors for aggravation, and the number of general hospital beds per population. The generalized estimating equations of negative binomial regression models were used to estimate the adjusted incidence proportion (AIP) with 95% confidence interval (CI) for severe COVID-19.

RESULTS

Among 77,044 patients included in the analysis, 14,556 (18.9%) were unvaccinated and 520 (0.7%) developed severe COVID-19. Among unvaccinated patients, the risk of severe COVID-19 increased in the Alpha/Delta variants and decreased in the Omicron variant compared to the wild-type (AIP [95% CI] was 1.55 [1.06-2.27] in Alpha/Delta and 0.25 [0.15-0.40] in Omicron), but differed by age. Especially in patients aged ≥80, there was no significant difference in the risk of severe COVID-19 between the wild-type and the Omicron variant (AIP [95% CI] = 0.59 [0.27-1.29]). Regarding the preventive effect of vaccines, among all study participants, the number of vaccinations was significantly associated with the prevention of severe COVID-19, regardless of variant type. After stratified analyses by age, patients aged ≥80 remained a significant association for all variant types. On the other hand, the number of vaccinations had no association in Omicron BA.5 of patients aged 18-64.

CONCLUSIONS

Patients aged ≥80 had less reduction in risk of severe COVID-19 during the Omicron variant period, and a greater preventive effect of vaccines against severe COVID-19, compared to younger people. Our findings suggest that booster vaccination is effective and necessary for older people, especially aged ≥80.

Vaccinating against a Novel Pathogen: A Critical Review of COVID-19 Vaccine Effectiveness Evidence

We study the experience with COVID-19 vaccination of an initially naïve population, which can inform planning for vaccination against the next novel, highly transmissible pathogen. We focus on the first two pandemic years (wild strain through Delta), because after the Omicron wave in early 2022, very few people were still SARS-CoV-2-naïve. Almost all were vaccinated, infected, or often both. We review the evidence on COVID-19 vaccine effectiveness (VE) and waning effectiveness over time and the relative effectiveness of the four principal vaccines used in developed Western countries: BNT162b2 (Pfizer-BioNTech), mRNA1273 (Moderna), Ad26.CoV2.S (Johnson&Johnson), and ChAdOx1-S (AstraZeneca). As a basis for our analysis, we conducted a PRISMA-compliant review of all studies on PubMed through 15 August 2022, reporting VE against four endpoints for these four vaccines: any infection, symptomatic infection, hospitalization, and death. The mRNA vaccines (BNT162b2, mRNA1273) had high initial VE against all endpoints but protection waned after approximately six months, with BNT162b2 declining faster than mRNA1273. Both mRNA vaccines outperformed the viral vector vaccines (Ad26.CoV2.S and ChAdOx1-S). A third "booster" dose, roughly six months after the initial doses, substantially reduced symptomatic infection, hospitalization, and death. In hindsight, a third dose should be seen as part of the normal vaccination schedule. Our analysis highlights the importance of the real-time population-level surveillance needed to assess evidence for waning, and the need for rapid regulatory response to this evidence.

Effectiveness of the pre-Omicron COVID-19 vaccines against Omicron in reducing infection, hospitalization, severity, and mortality compared to Delta and other variants: A systematic review

Despite widespread mass rollout programs, the rapid spread of the SARS-CoV-2 Omicron variant called into question the effectiveness of the existing vaccines against infection, hospitalization, severity, and mortality compared to previous variants. This systematic review summarizes and compares the effectiveness of the COVID-19 vaccines, with respect to the above outcomes in adults, children, and adolescents. A comprehensive literature search was undertaken on several databases. Only 51 studies met our inclusion criteria, revealing that the protection from primary vaccination against Omicron infection is inferior to protection against Delta and Alpha infections and wanes faster over time. However, mRNA vaccine boosters were reported to reestablish effectiveness, although to a lower extent against Omicron. Nonetheless, primary vaccination was shown to preserve strong protection against Omicron-associated hospitalization, severity, and death, even months after last dose. However, boosters provide more robust and longer-lasting protection against hospitalizations due to Omicron as compared to only primary series.

Design and analysis heterogeneity in observational studies of COVID-19 booster effectiveness: A review and case study

We investigated the design and analysis of observational booster vaccine effectiveness (VE) studies by performing a scoping review of booster VE literature with a focus on study design and analytic choices. We then applied 20 different approaches, including those found in the literature, to a single dataset from Michigan Medicine. We identified 80 studies in our review, including over 150 million observations in total. We found that while protection against infection is variable and dependent on several factors including the study population and time period, both monovalent boosters and particularly the bivalent booster offer strong protection against severe COVID-19. In addition, VE analyses with a severe disease outcome (hospitalization, intensive care unit admission, or death) appear to be more robust to design and analytic choices than an infection endpoint. In terms of design choices, we found that test-negative designs and their variants may offer advantages in statistical efficiency compared to cohort designs.

Preinfection Neutralizing Antibodies, Omicron BA.5 Breakthrough Infection, and Long COVID: A Propensity Score-Matched Analysis

BACKGROUND

Data are limited on the role of preinfection humoral immunity protection against Omicron BA.5 infection and long coronavirus disease (COVID) development.

METHODS

We conducted nested case-control analysis among tertiary hospital staff in Tokyo who donated blood samples in June 2022 (1 month before Omicron BA.5 wave), approximately 6 months after receiving a third dose of COVID-19 mRNA vaccine. We measured live virus-neutralizing antibody titers against wild type and Omicron BA.5, and anti-receptor-binding domain (RBD) antibody titers at preinfection, and compared them between cases and propensity-matched controls. Among the breakthrough cases, we examined association between preinfection antibody titers and incidence of long COVID.

RESULTS

Preinfection anti-RBD and neutralizing antibody titers were lower in cases than controls. Neutralizing titers against wild type and Omicron BA.5 were 64% (95% confidence interval [CI], 42%-77%) and 72% (95% CI, 53%-83%) lower, respectively, in cases than controls. Individuals with previous Omicron BA.1/BA.2 infections were more frequent among controls than cases (10.3% vs 0.8%), and their Omicron BA.5 neutralizing titers were 12.8-fold higher than infection-naive individuals. Among cases, preinfection antibody titers were not associated with incidence of long COVID.

CONCLUSIONS

Preinfection immunogenicity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may play a role in protecting against the Omicron BA.5 infection but not preventing long COVID.

Effectiveness of COVID-19 vaccines among children and adolescents against SARS-CoV-2 variants: a meta-analysis

This systematic review and meta-analysis aimed to evaluate the effectiveness of COVID-19 vaccines among children and adolescents against SARS-CoV-2 variants. We searched PubMed, Embase, Web of Science, the Cochrane Library, and ClinicalTrials.gov for studies published on or before June 20, 2023. Studies evaluating the effectiveness of COVID-19 vaccines in children and adolescents (≤ 18 years of age) were included. Data extraction, quality assessment, and analysis were conducted following PRISMA guidelines. Ten studies were included, comprising five cohort studies (527,778 participants) and four case-control studies (1,477,422 participants). The overall vaccine effectiveness (VE) against SARS-CoV-2 variants was 68% (95% CI = 60-74%). In terms of age, the VE was higher in adolescents aged 12-18 years [69%(95% CI = 61-75%)] than in children aged 5-11 years [44%(95% CI = 1-68%)]. "Fully vaccinated" may offer greater protection than "partially vaccinated," with a VE of 71% (95%CI = 59-79%) and 66% (95%CI = 51-76%), respectively.    Conclusion: This meta-analysis presents moderate-quality evidence that the COVID-19 vaccine is effective in safeguarding children and adolescents from the SARS-CoV-2 variant. Being fully vaccinated may offer greater protection than being partially vaccinated. Nevertheless, additional high-quality controlled trials are required to verify this finding. What is Known: • The COVID-19 pandemic has led to the rapid development and deployment of vaccines worldwide. Children and adolescents are a unique population for vaccination, and the effectiveness of vaccines against SARS-CoV-2 variants in this age group is of concern. What is New: • The COVID-19 vaccine is effective in protecting children and adolescents against the SARS-CoV-2 variant. Being fully vaccinated may offer greater protection than being partially vaccinated.

Innovation-driven trend shaping COVID-19 vaccine development in China

Confronted with the Coronavirus disease 2019 (COVID-19) pandemic, China has become an asset in tackling the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission and mutation, with several innovative platforms, which provides various technical means in this persisting combat. Derived from collaborated researches, vaccines based on the spike protein of SARS-CoV-2 or inactivated whole virus are a cornerstone of the public health response to COVID-19. Herein, we outline representative vaccines in multiple routes, while the merits and plights of the existing vaccine strategies are also summarized. Likewise, new technologies may provide more potent or broader immunity and will contribute to fight against hypermutated SARS-CoV-2 variants. All in all, with the ultimate aim of delivering robust and durable protection that is resilient to emerging infectious disease, alongside the traditional routes, the discovery of innovative approach to developing effective vaccines based on virus properties remains our top priority.

M, Armas R, de Mora D, Pinos J, Olmedo A, Salas R, Jimbo-Sotomayor R, Chiluisa C, Acosta P, Sánchez X, Whittembury A. Effectiveness of COVID-19 vaccines in Ecuador: A test-negative design

Background

The COVID-19 pandemic poses a significant global health threat, characterized by high morbidity, severity, and the emergence of concerning variants. Latin America has been greatly affected, with high infection and mortality rates. Vaccination plays a crucial role in mitigating severe disease and controlling the pandemic. This study aims to assess the effectiveness of COVID-19 vaccines in preventing SARS-CoV-2 severe acute respiratory infections (SARI) in hospitalized vaccination target groups in Ecuador.

Methods

This is a test-negative design study. We used data reported through sentinel surveillance of SARI between May 2021 and March 2022 in Ecuador. Patients with case criteria of SARI and hospitalized for a minimum of 24 hours were included in the study. Cases were defined as patients with SARI with a positive RT-qPCR test for SARS-CoV-2 and controls were those with a negative result. Information on vaccination status was obtained from the national vaccination registry, a valid dose of vaccination was considered when it was administered at least 14 days prior to symptom onset. Vaccine effectiveness (VE) (1-OR/OR) was calculated using a logistic regression.

Results

A total of 1,277 patients were included in the analysis of VE. The adjusted vaccine effectiveness (aVE) in preventing hospitalization, adjusted for sex, age group, presence of one or more comorbidities, and period of the predominance of the omicron variant, was 44.5% for the partial primary schedule, 74.7% for the complete primary schedule, and 79.9% for the complete primary schedule plus booster doses. The aVE in avoiding ICU admissions was close to 80% with both the complete primary schedule and the booster doses, and in avoiding deaths, the aVE was 89% and 98%, respectively.

Conclusions

In Ecuador, COVID-19 vaccination prevents hospitalizations, ICU admissions, and deaths. The effectiveness of the vaccines improves with more doses, offering increased protection across all age groups.

Quantifying the benefits of healthy lifestyle behaviors and emotional expressivity in lowering the risk of COVID-19 infection: a national survey of Chinese population

BACKGROUND

COVID-19 is still prevalent in most countries around the world at the low level. Residents' lifestyle behaviors and emotions are critical to prevent COVID-19 and keep healthy, but there is lacking of confirmative evidence on how residents' lifestyle behaviors and emotional expressivity affected COVID-19 infection.

METHODS

Baseline study was conducted in August 2022 and follow-up study was conducted in February 2023. Baseline survey collected information on residents' basic information, as well as their lifestyle behaviors and emotions. Follow-up study was carried out to gather data on COVID-19 infection condition. Binary logistic regression was utilized to identify factors that may influence COVID-19 infection. Attributable risk (AR) was computed to determine the proportion of unhealthy lifestyle behaviors and emotional factors that could be attributed to COVID-19 infection. Sensitivity analysis was performed to test the robustness of the results.

RESULTS

A total of 5776 participants (46.57% males) were included in this study, yielding an overall COVID-19 infection rate of 54.8% (95%CI: 53.5 - 56.0%). The findings revealed that higher stress levels [aOR = 1.027 (95%CI; 1.005-1.050)] and lower frequency in wearing masks, washing hands, and keeping distance [aOR = 1.615 (95%CI; 1.087-2.401)], were positively associated with an increased likelihood of COVID-19 infection (all P < 0.05). If these associations were causal, 8.1% of COVID-19 infection would have been prevented if all participants had normal stress levels [Attributable Risk Percentage: 8.1% (95%CI: 5.9-10.3%)]. A significant interaction effect between stress and the frequency in wearing masks, washing hands, and keeping distance on COVID-19 infection was observed (β = 0.006, P < 0.001), which also was independent factor of COVID-19 infection.

CONCLUSIONS

The overall COVID-19 infection rate among residents is at a medium level. Residents' increasing stress and decreasing frequency in wearing masks and washing hands and keeping distance contribute to increasing risk of infection, residents should increase the frequency of mask-wearing, practice hand hygiene, keep safe distance from others, ensure stable emotional state, minimize psychological stress, providing evidence support for future responses to emerging infectious diseases.

A booster dose of SARS-COV-2 vaccine improves suboptimal seroconversion rates in patients with inflammatory bowel disease. Results of a prospective multicenter study of GETECCU (VACOVEII study)

BACKGROUND

The response to SARS-CoV-2 vaccination decreases in inflammatory bowel disease (IBD) patients, specially under anti-TNF treatment. However, data on medium-term effectiveness are limited, specially using new recommended seroconversion rate (>260BAU/mL). Our aim was to evaluate the 6-month>260 BAU-seroconversion rate after full vaccination and after booster-dose.

METHODS

VACOVEII is a Spanish multicenter, prospective study promoted by GETECCU. IBD patients full vaccinated against SARS-CoV-2 and without previous COVID-19 infection, treated or not with immunosuppressants, were included. The booster dose was administered 6 months after the full vaccination. Seroconversion was set at 260BAU/mL, according to most recent recommendations and was assessed 6 months after the full vaccination and 6 months after booster-dose.

RESULTS

Between October 2021 and March 2022, 313 patients were included (124 no treatment or mesalazine; 55 immunomodulators; 87 anti-TNF; 19 anti-integrin; and 28 ustekinumab). Most patients received mRNA-vaccines (86%). Six months after full vaccination, overall seroconversion rate was 44.1%, being significantly lower among patients on anti-TNF (19.5%, p<0.001) and ustekinumab (35.7%, p=0.031). The seroconversion rate after booster was 92%. Again, anti-TNF patients had a significantly lower seroconversion rate (67%, p<0.001). mRNA-vaccine improved seroconversion rate (OR 11.720 [95% CI 2.26-60.512]).

CONCLUSION

The full vaccination regimen achieves suboptimal response in IBD patients, specially among those anti-TNF or ustekinumab. The booster dose improves seroconversion rate in all patients, although it remains limited in those treated with anti-TNF. These results reinforce the need to prioritize future booster doses in patients on immunosuppressants therapy, specially under anti-TNF, and using mRNA-vaccines.

Immune escape of SARS-CoV-2 variants to therapeutic monoclonal antibodies: a system review and meta-analysis

BACKGROUND

Omicron's high transmissibility and variability present new difficulties for COVID-19 vaccination prevention and therapy. In this article, we analyzed the sensitivity of vaccine-induced antibodies as well as the effect of booster vaccinations against Omicron sublineages.

METHODS

We looked for Randomized Controlled Trials and cohort studies that reported the COVID-19 vaccines against Omicron sublineages up to 28 July 2022 through PubMed, the Cochrane Library, EMBASE, and Web of Science. Quantitative synthesis was carried out using Stata 16.0 and RevMa5.3, then the serum NT50 and antibody sensitivity to neutralize Omicron sublineages were assessed before and after booster vaccination. This study was registered with PROSPERO number CRD42022350477.

RESULTS

This meta-analysis included 2138 patients from 20 studies, and the booster vaccination against Omicron sublineages showed a significant difference compared to 2 dosage: BA.1/BA.1.1 (SMD = 0.80, 95% CI: 0.75-0.85, P = 0.00), BA.2/BA.2.12.1 (SMD = 0.77, 95% CI: 0.69-0.85, P = 0.00), BA.3 (SMD = 0.91, 95% CI: 0.83-1.0, P = 0.00), and BA.4/5 (SMD = 0.77, 95% CI: 0.60-0.94, P = 0.00). The sensitivity of vaccines-induced antibodies decreased by at least 5-folds after booster vaccination, particularly in the case of BA.4/5 which had the most notable decline in vaccine effectiveness.

CONCLUSION

After the booster vaccination, the NT50 and the neutralization ability of vaccine-induced antibodies increased, but the susceptibility of antibodies decreased compared with the control virus, which may be a clue for future Omicron sublineages prevention.