Safety, tolerability, and immunogenicity of an inactivated SARS-CoV-2 vaccine (CoronaVac) in healthy adults aged 60 years and older: a randomised, double-blind, placebo-controlled, phase 1/2 clinical trial

Effect of Inactivated Vaccines Against SARS-CoV-2 on Immunogenicity Outcome

OBJECTIVES

The purpose of this study was to measure and examine the levels of IgG, IgM, and Spike antibody induced by inactivated vaccines, including CoronaVac and BBIBP-CorV.

METHODS

Two groups of healthy adults over 18 years old (50 participants per group), who had previously received 1 dose of either BBIBP-CorV or CoronaVac and receiving either a homologous booster of BBIBP-CorV or a heterologous booster of CoronaVac. Serum IgG, IgM, and Spike antibody levels against SARS-COV-2 were measured using magnetic particle chemiluminescence immunoassay and the ELISA method.

RESULTS

The results showed that both spike antibody and IgG/IgM antibodies elicited by a CoronaVac booster following 1 dose of BBIBP-CorV were significantly higher than those elicited by either a homologous BBIBP-CorV booster or a heterologous BBIBP-CorV booster. The Spike antibody against SARS-COV-2 induced by the heterologous CoronaVac booster reached 200.3, which is substantially greater than that induced by the homologous BBIBP-CorV booster (127.5 pg/mL). Conversely, the Spike antibody against SARS-COV-2 induced by the heterologous BBIBP-CorV booster reached 53.93 pg/mL, which is substantially greater than that induced by the homologous CoronaVac booster (9.60 pg/mL).

CONCLUSIONS

In summary, CoronaVac is immunogenic as a booster dose following 1 dose of BBIBP-CorV and is immunogenically superior to both the homologous booster and the heterologous BBIBP-CorV booster.

Evaluating the safety profile of the CoronaVac in adult and older adult populations: A phase IV prospective observational study in Brazil

This Phase IV prospective observational study aimed to evaluate the frequency of solicited and unsolicited adverse reactions within seven days following the administration of each dose of CoronaVac (14-day interval) by age group (18-59 years and ≥60 years). Participants (n = 538; 487 adults and 51 older adults) were enrolled from three public health centers in São Paulo, Brazil from May 2021 to January 2022. The study involved a two-dose vaccination regimen administered 14 days apart. Solicited and unsolicited adverse reactions (ARs) were assessed within seven days after each dose, and medically attended adverse events following immunization (AEFI) were monitored for 42 days. Safety data were collected through participant diary cards, telephone follow-ups, and on-site visits. Among adults, the most frequently reported local AR after the first and second doses was pain (256 [52.6%] and 129 [29.5%], respectively), while the most common systemic AR was headache (158 [34.5%] and 51 [11.6%], respectively). Most local and systemic solicited ARs were of Grade 1 or 2 severity, with ARs being more prevalent in adults following the first dose. One serious adverse event related to the vaccine was reported in adults, with no fatalities. Nine adult participants experienced adverse events of special interest, including five cases of COVID-19. These findings support the overall safety profile of CoronaVac in adults and older adult individuals, with adverse events being generally mild and self-limited.

Quantitative and qualitative analysis of seroconversion after one year of vaccination with inactivated SARS-CoV-2 vaccine (CoronaVac®) in healthcare workers: Cross-sectional analytical study

A descriptive study was carried out with health professionals in Sao Paulo city. Were included individuals vaccinated with 2 doses of the inactivated vaccine. Demographic, clinical and vaccination information was obtained from professionals with or without comorbidities. Two serological assays were used to identify the presence and quantity of anti-Spike IgG in serum samples. 433 healthy healthcare professionals were included and 58.9 % completed the 4 clinical stages of serological assessment. Among adults and elderly people, 25.2 % had chronic diseases (hypertension 50.5 %, diabetes 10 % and obesity 6.5 %). Most individuals have 95 % protection in the first 3 months after the second dose, and 67.68 % protection after 6 months. Total antibodies ranged from 3 to 10 on the reactivity index, and the anti-RBD IgG levels were high. CoronaVac has a 94 % seroconversion rate after 2 doses and can prevent serious cases and outbreaks of the disease, if used on a large scale.

Dynamics of SARS-CoV-2 infection over two epidemic waves in Manaus, Brazil: A serological study of seven thousand blood donors

BACKGROUND

Most longitudinal studies of COVID-19 incidence have used unlinked samples. The city of Manaus, Brazil, has a blood donation program which allows sample linkage, and was struck by two large COVID-19 epidemic waves between mid-2020 and early 2021.

METHODS

We estimated the changing force of infection, i.e. incidence in susceptible individuals. Seroconversion was inferred by a mixture model for serial values from the Abbott Architect SARS-CoV-2 nucleocapsid (N) IgG assay. We estimated the number of suspected COVID-19 hospitalizations arising from each infection over calendar time.

RESULTS

Whole blood donations between April 2020 and March 2021 were included from 6734 people, 2747 with two or more donations. The inferred criterion for seroconversion, and thus an incident infection, was a 6.07 fold increase in N IgG reactivity. The overall force of infection was 1.19 per person year (95% confidence interval 1.14-1.24) during the two main waves. The estimated number of suspected hospitalizations per infection, was approximately 4.1 times higher in the second wave than in the first.

CONCLUSIONS

Serial values from this assay can be used to infer seroconversion over time, and in Manaus show a higher number of suspected COVID-19 hospitalizations per infection in the second wave relative to the first.

Safety observation of COVID-19 inactivated vaccine in immature mice

OBJECTIVE

To investigate the safety of COVID-19 inactivated vaccine in immature mice.

METHODS

We selected 3-week-old immature BALB/c mice, continuously observed until 7 weeks old after continuous immunization with fully inactivated vaccine (initial strengthening), and sacrificed BALB/c mice at 7 weeks old, and used H&E, Masson, mast cells and Ki-67 staining to analyze the changes of heart, liver, spleen, kidney, lung and brain. In addition, RNA was extracted from important organs such as the heart, liver, spleen, kidney, lung, and brain, and to evaluate whether there was any effect after vaccination through bulk-RNA sequencing.

RESULTS

After H&E, Masson, mast cells and Ki-67 staining analyses, there are no significant differences between tissues and organs in the vaccine group and the PBS group, and RNA-Seq did not show that the vaccine had any effect on immature mice.

CONCLUSION

COVID-19 inactivated vaccine is safe in immature mice.

Is COVID-19 Vaccination Beneficial for Tumor Patients: A Cross-Sectional Investigation in China

INTRODUCTION

Tumor patients take a high risk of SARS-CoV-2 infection, high incidence of serious events, poor prognosis and high mortality in the coronavirus disease 2019 (COVID-19) epidemic, but there is still lack of supporting evidence that the COVID-19 vaccination is beneficial for tumor patients to encourage them to receive the vaccination.

METHODS

A cross-sectional study was conducted in Shantou, China and questionnaires were collected in the hospitals from February 13, 2023 to April 23, 2023. Using the receiving of COVID-19 vaccination as the primary outcome, descriptive, univariate and multivariate analyses were generated.

RESULTS

161 out of 241 patients (66.80%) had received at least one dose of COVID-19 vaccine and 61.00% patients had been infected with SARS-CoV-2. Patients with general symptoms (p = 0.013) and others (p = 0.022) had a higher proportion of nonvaccinated patients than vaccinated ones. In the multivariate analysis, age (aOR = 0.971, 95% CI = 0.946-0.997, p = 0.031), the cognition of vaccines' impact on tumor treatment (aOR = 4.475, 95% CI = 1.772-11.299, p = 0.002), time since tumor diagnosis (aOR = 4.586, 95% CI = 2.122-9.909, p < 0.001) were identified as factors of COVID-19 vaccination uptake.

CONCLUSION

COVID-19 vaccination in China offers numerous advantages for tumor patients, helping to alleviate symptoms following infection and potentially decreasing the chances of tumor metastasis and recurrence.

Safety, tolerability, and immunogenicity of PIKA-adjuvanted recombinant SARS-CoV-2 spike protein subunit vaccine in healthy adults: an open-label randomized phase I clinical trial

Purpose

This phase I study aimed to assess the safety, tolerability, and immunogenicity of the PIKA-adjuvanted recombinant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein subunit vaccine in healthy adults aged 18 years and older.

Materials and Methods

This is a phase I, open-label, dose-escalation study at three dose levels (5 µg, 10 µg, and 20 µg) of the PIKA coronavirus disease 2019 (COVID-19) vaccine administered intramuscularly. The three vaccine arms are (A) subjects who have never received any COVID-19 vaccination or have had COVID-19 infection for >6 months prior to enrolment; (B1) subjects whose COVID-19 primary vaccination series was completed with an inactivated COVID-19 vaccine; and (B2) subjects whose primary series was completed with messenger RNA COVID-19 vaccine.

Results

Subjects who reported solicited adverse events (AEs) within seven days post-vaccination ranged from 35% to 60% within each vaccine arm. Most solicited AEs were mild local pain and tenderness. Systemic solicited AEs were only reported in Arm A. In all three vaccine arms, neutralizing antibody geometric mean titers were highest at day 28 (Arms B1 and B2) or day 35 (Arm A) than at baseline for all dose levels against the Wuhan (wild original SARS-CoV-2 virus, Wuhan-Hu-1), Delta (B.1.617.2), and Omicron (B.1.1.529) variants. These were sustained at day 183. Seroconversion rates at day 35 (Arm A, 85.7%-92.9%) or day 183 (Arms B1, 90.9%-100.0%, and B2, 18.2%-36.4%) and geometric mean fold rises were highest in the 5-µg dose level against all three variants.

Conclusion

The PIKA-adjuvanted recombinant SARS-CoV-2 S protein subunit vaccine showed promising immunogenicity profile with no safety concerns. A dose-dependent immune response was observed, with slight advantages seen in low-dose (5 µg and 10 µg) groups (ClinicalTrials.gov registration number: NCT05305300).

Safety and immunogenicity of PIKA-adjuvanted recombinant SARS-CoV-2 spike protein subunit vaccine as a booster against SARS-CoV-2: a phase II, open-label, randomized, double-blinded study

Purpose

This study evaluated the safety and immunogenicity of the PIKA-adjuvanted recombinant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein subunit vaccine as a booster dose for healthy adults who had previously received two or more doses of an inactivated coronavirus disease 2019 (COVID-19) vaccine.

Materials and Methods

The study was a phase II multicenter, double-blinded, comparator-controlled, randomized trial. Participants were randomly assigned to receive either the PIKA COVID-19 vaccine booster dose or an inactivated COVID-19 vaccine (Sinovac, China). Safety was assessed based on adverse events, while immunogenicity was measured by neutralizing antibodies against SARS-CoV-2 and serum immunoglobulin G (IgG) levels. Data on safety and immunogenicity were collected in the short-term (within 14 days after the booster dose) and long-term (from 90 to 365 days after the booster dose).

Results

The PIKA-adjuvanted vaccine demonstrated a significant increase in neutralizing antibodies against the Omicron variant (geometric mean ratio [GMR]=2.0 on day 7, p-value <0.001; GMR=2.7 on day 14, p-value <0.001) and the wild type SARS-CoV-2 virus (GMR=2.3 on day 7, p-value <0.001; GMR=2.8 on day 14, p-value<0.001) in the early post-vaccination period when compared to the inactivated vaccine. Additionally, the PIKA COVID-19 vaccine showed higher seroconversion rates for neutralizing antibodies against both variants during the first 14 days post-vaccination. However, there were no significant differences in neutralizing antibody levels between the two vaccines from day 90 to day 360 post-vaccination. Serum IgG antibody levels for the PIKA COVID-19 vaccine were also higher throughout the study period. The incidence of adverse events was slightly higher in the PIKA COVID-19 group, with the most common events being pain at the injection site and headache. All adverse events were mild or moderate, with no reports of severe or life-threatening adverse events in either group.

Conclusion

The PIKA COVID-19 vaccine, when administered as a booster dose, showed promising short- and long-term immunogenicity with no emergent safety issues identified. The booster dose of the PIKA COVID-19 vaccine elicited a robust immune response against various SARS-CoV-2 variants and provided some seroprotection for up to 360 days (ClinicalTrials.gov registration number: NCT05463419).

In Silico Design of a Trans-Amplifying RNA-Based Vaccine against SARS-CoV-2 Structural Proteins

Nucleic acid-based vaccines allow scalable, rapid, and cell-free vaccine production in response to an emerging disease such as the current COVID-19 pandemic. Here, we objected to the design of a multiepitope mRNA vaccine against the structural proteins of SARS-CoV-2. Through an immunoinformatic approach, promising epitopes were predicted for the spike (S), envelope (E), membrane (M), and nucleocapsid (N) proteins. Fragments rich in overlapping epitopes were selected based on binding affinities with HLA classes I and II for the specific presentation to B and T lymphocytes. Two constructs were designed by fusing the fragments in different arrangements via GG linkers. Construct 1 showed better structural properties and interactions with toll-like receptor 2 (TLR-2), TLR-3, and TLR-4 during molecular docking and dynamic simulation. A 50S ribosomal L7/L12 adjuvant was added to its N-terminus to improve stability and immunogenicity. The final RNA sequence was used to design a trans-amplifying RNA (taRNA) vaccine in a split-vector system. It consists of two molecules: a nonreplicating RNA encoding a trans-acting replicase to amplify the second one, a trans-replicon (TR) RNA encoding the vaccine protein. Overall, the immune response simulation detected that activated B and T lymphocytes and increased memory cell formation. Macrophages and dendritic cells proliferated continuously, and IFN-γ and cytokines like IL-2 were released highly.

Emerging and reemerging infectious diseases: global trends and new strategies for their prevention and control

To adequately prepare for potential hazards caused by emerging and reemerging infectious diseases, the WHO has issued a list of high-priority pathogens that are likely to cause future outbreaks and for which research and development (R&D) efforts are dedicated, known as paramount R&D blueprints. Within R&D efforts, the goal is to obtain effective prophylactic and therapeutic approaches, which depends on a comprehensive knowledge of the etiology, epidemiology, and pathogenesis of these diseases. In this process, the accessibility of animal models is a priority bottleneck because it plays a key role in bridging the gap between in-depth understanding and control efforts for infectious diseases. Here, we reviewed preclinical animal models for high priority disease in terms of their ability to simulate human infections, including both natural susceptibility models, artificially engineered models, and surrogate models. In addition, we have thoroughly reviewed the current landscape of vaccines, antibodies, and small molecule drugs, particularly hopeful candidates in the advanced stages of these infectious diseases. More importantly, focusing on global trends and novel technologies, several aspects of the prevention and control of infectious disease were discussed in detail, including but not limited to gaps in currently available animal models and medical responses, better immune correlates of protection established in animal models and humans, further understanding of disease mechanisms, and the role of artificial intelligence in guiding or supplementing the development of animal models, vaccines, and drugs. Overall, this review described pioneering approaches and sophisticated techniques involved in the study of the epidemiology, pathogenesis, prevention, and clinical theatment of WHO high-priority pathogens and proposed potential directions. Technological advances in these aspects would consolidate the line of defense, thus ensuring a timely response to WHO high priority pathogens.

The gut microbiota modifies antibody durability and booster responses after SARS-CoV-2 vaccination

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines are pivotal in combating coronavirus disease 2019 (COVID-19); however, the declining antibody titers postvaccination pose challenges for sustained protection and herd immunity. Although gut microbiome is reported to affect the early antibody response after vaccination, its impact on the longevity of vaccine-induced antibodies remains unexplored.

METHODS

A prospective cohort study was conducted involving 44 healthy adults who received two doses of either the BNT162b2 or ChAdOx1 vaccine, followed by a BNT162b2 booster at six months. The gut microbiome was serially analyzed using 16S rRNA and shotgun sequencing, while humoral immune response was assessed using a SARS-CoV-2 spike protein immunoassay.

RESULTS

Faecalibacterium prausnitzii was associated with robust and persistent antibody responses post-BNT162b2 vaccination. In comparison, Escherichia coli was associated with a slower antibody decay following ChAdOx1 vaccination. The booster immune response was correlated with metabolic pathways involving cellular functions and aromatic amino acid synthesis.

CONCLUSIONS

The findings of this study underscored the potential interaction between the gut microbiome and the longevity/boosting effect of antibodies following vaccination against SARS-CoV-2. The identification of specific microbial associations suggests the prospect of microbiome-based strategies for enhancing vaccine efficacy.

Individuals carrying the HLA-B*15 allele exhibit favorable responses to COVID-19 vaccines but are more susceptible to Omicron BA.5.2 and XBB.1.16 infection

Background

Natural infection or vaccination have provided robust immune defense against SARS-CoV-2 invasion, nevertheless, Omicron variants still successfully cause breakthrough infection, and the underlying mechanisms are poorly understood.

Methods

Sequential blood samples were continuously collected at different time points from 252 volunteers who were received the CanSino Ad5-nCoV (n= 183) vaccine or the Sinovac CoronaVac inactivated vaccine (n= 69). The anti-SARS-CoV-2 prototype and Omicron BA.5.2 as well as XBB.1.16 variant neutralizing antibodies (Nab) in sera were detected by ELISA. Sera were also used to measure pseudo and live virus neutralization assay. The associations between the anti-prototype Nab levels and different HLA-ABC alleles were analyzed using artificial intelligence (AI)-deep learning techniques. The frequency of B cells in PBMCs was investigated by flow cytometry assay (FACs).

Results

Individuals carrying the HLA-B*15 allele manifested the highest concentrations of anti-SARS-CoV-2 prototype Nab after vax administration. Unfortunately, these volunteers are more susceptible to Omicron BA.5.2 breakthrough infection due to their sera have poorer anti-BA.5.2 Nab and lower levels of viral neutralization efficacy. FACs confirmed that a significant decrease in CD19+CD27+RBD+ memory B cells in these HLA-B*15 population compared to other cohorts. Importantly, generating lower concentrations of cross-reactive anti-XBB.1.16 Nab post-BA.5.2 infection caused HLA-B*15 individuals to be further infected by XBB.1.16 variant.

Conclusions

Individuals carrying the HLA-B*15 allele respond better to COVID-19 vax including the CanSino Ad5-nCoV and the Sinovac CoronaVac inactivated vaccines, but are more susceptible to Omicron variant infection, thus, a novel vaccine against this population is necessary for COVID-19 pandemic control in the future.

Booster Vaccination with BNT162b2 Improves Cellular and Humoral Immune Response in the Pediatric Population Immunized with CoronaVac

The SARS-CoV-2 Omicron variant and its sublineages continue to cause COVID-19-associated pediatric hospitalizations, severe disease, and death globally. BNT162b2 and CoronaVac are the main vaccines used in Chile. Much less is known about the Wuhan-Hu-1 strain-based vaccines in the pediatric population compared to adults. Given the worldwide need for booster vaccinations to stimulate the immune response against new Omicron variants of SARS-CoV-2, we characterized the humoral and cellular immune response against Omicron variant BA.1 in a pediatric cohort aged 10 to 16 years who received heterologous vaccination based on two doses of CoronaVac, two doses of CoronaVac (2x) plus one booster dose of BNT162b2 [CoronaVac(2x) + BNT162b2 (1x)], two doses of CoronaVac plus two booster doses of BNT162b2 [CoronaVac(2x) + BNT162b2 (2x)], and three doses of BNT162b2. We observed that the [CoronaVac(2x) + BNT162b2 (2x)] vaccination showed higher anti-S1 and neutralizing antibody titers and CD4 and CD8 T cell immunity specific to the Omicron variant compared to immunization with two doses of CoronaVac alone. Furthermore, from all groups tested, immunity against Omicron was highest in individuals who received three doses of BNT162b2. We conclude that booster vaccination with BNT162b2, compared to two doses of CoronaVac alone, induces a greater protective immunity.

Efficacy, immunogenicity and safety of CoronaVac® in children and adolescents aged 6 months to 17 years: a multicenter, randomized, double-blind, placebo-controlled phase III clinical trial

Safe and effective vaccines against COVID-19 for children and adolescents are needed. This international multicenter, randomized, double-blind, placebo-controlled, phase III clinical trial assessed the efficacy, immunogenicity, and safety of CoronaVac® in children and adolescents (NCT04992260). The study was carried out in Chile, South Africa, Malaysia, and the Philippines. The enrollment ran from September 10, 2021 to March 25, 2022. For efficacy assessment, the median follow-up duration from 14 days after the second dose was 169 days. A total of 11,349 subjects were enrolled. Two 3-μg injections of CoronaVac® or placebo were given 28 days apart. The primary endpoint was the efficacy of the CoronaVac®. The secondary endpoints were the immunogenicity and safety. The vaccine efficacy was 21.02% (95% CI: 1.65, 36.67). The level of neutralizing antibody in the vaccine group was significantly higher than that in the placebo group (GMT: 390.80 vs. 62.20, P <0.0001). Most adverse reactions were mild or moderate. All the severe adverse events were determined to be unrelated to the investigational products. In conclusion, in the Omicron-dominate period, a two-dose schedule of 3 μg CoronaVac® was found to be safe and immunogenic, and showed potential against symptomatic COVID-19 in healthy children and adolescents.

Obstetric outcomes of women vaccinated with the COVID-19 vaccine (≥1 dose): A single-center retrospective cohort study of pregnant Chinese women

In the context of the coronavirus disease 2019 (COVID-19) pandemic, the quickly developed COVID-19 vaccine may cause various adverse reactions, especially in special groups, such as pregnant women. However, many pregnant women have concerns regarding vaccination in terms of safety for themselves and their neonates. Therefore, we studied the obstetric outcomes of pregnant women in Zunyi, China. In this retrospective study, we examined differences between pregnant women who were vaccinated and pregnant women who were not vaccinated/vaccinated at the end of pregnancy. In addition, we collected and retrieved the literature related to the COVID-19 vaccine and pregnancy outcomes from PubMed. Among concluded women, 369 were included in the study group and 231 were included in the control group. There were no differences in the baseline characteristics, labor rate, or rates of poor pregnancy outcomes between the 2 groups. Based on the adverse reaction and obstetric outcome data of pregnant women who received the COVID-19 vaccine in China, the vaccine does not raise any safety concerns. This result is the same as that of other countries we summarized. The COVID-19 vaccine has no effect on pregnancy outcomes.

SARS-CoV-2 Vaccines: The Advantage of Mucosal Vaccine Delivery and Local Immunity

Immunity against respiratory pathogens is often short-term, and, consequently, there is an unmet need for the effective prevention of such infections. One such infectious disease is coronavirus disease 19 (COVID-19), which is caused by the novel Beta coronavirus SARS-CoV-2 that emerged around the end of 2019. The World Health Organization declared the illness a pandemic on 11 March 2020, and since then it has killed or sickened millions of people globally. The development of COVID-19 systemic vaccines, which impressively led to a significant reduction in disease severity, hospitalization, and mortality, contained the pandemic's expansion. However, these vaccines have not been able to stop the virus from spreading because of the restricted development of mucosal immunity. As a result, breakthrough infections have frequently occurred, and new strains of the virus have been emerging. Furthermore, SARS-CoV-2 will likely continue to circulate and, like the influenza virus, co-exist with humans. The upper respiratory tract and nasal cavity are the primary sites of SARS-CoV-2 infection and, thus, a mucosal/nasal vaccination to induce a mucosal response and stop the virus' transmission is warranted. In this review, we present the status of the systemic vaccines, both the approved mucosal vaccines and those under evaluation in clinical trials. Furthermore, we present our approach of a B-cell peptide-based vaccination applied by a prime-boost schedule to elicit both systemic and mucosal immunity.

The Protective Efficacy of a SARS-CoV-2 Vaccine Candidate B.1.351V against Several Variant Challenges in K18-hACE2 Mice

The emergence of SARS-CoV-2 variants of concern (VOCs) with increased transmissibility and partial resistance to neutralization by antibodies has been observed globally. There is an urgent need for an effective vaccine to combat these variants. Our study demonstrated that the B.1.351 variant inactivated vaccine candidate (B.1.351V) generated strong binding and neutralizing antibody responses in BALB/c mice against the B.1.351 virus and other SARS-CoV-2 variants after two doses within 28 days. Immunized K18-hACE2 mice also exhibited elevated levels of live virus-neutralizing antibodies against various SARS-CoV-2 viruses. Following infection with these viruses, K18-hACE2 mice displayed a stable body weight, a high survival rate, minimal virus copies in lung tissue, and no lung damage compared to the control group. These findings indicate that B.1.351V offered protection against infection with multiple SARS-CoV-2 variants in mice, providing insights for the development of a vaccine targeting SARS-CoV-2 VOCs for human use.

SARS-CoV-2 Vaccination Improves Semen Quality in Men Recovered From COVID-19: A Retrospective Cohort Study

Coronavirus disease 2019 (COVID-19) has been reported to decrease semen quality in reproductive-age men. Semen quality in vaccinated men after SARS-CoV-2 infection remains unclear. We recruited reproductive-age Chinese men scheduled for COVID-19 vaccination from December 2022 to March 2023. Among 1,639 vaccinated participants, an upward trend was found in sperm concentration (p < .001), progressive motility (p < .001), total motility (p < .001), total motile sperm count (TMSC) (p < .001), and normal morphology (p = .01) over time following COVID-19 recovery. Among men with an SARS-CoV-2 infection that lasted less than 30 days, men who received an inactivated vaccine booster had higher sperm progressive (p = .006) and total motility (p = .005) as well as TMSC (p = .008) than those without a booster vaccine, whereas no difference was found in semen parameters among men who received a recombinant protein vaccine. Similarly, an upward trend in semen quality was found among 122 men who provided semen samples before and after COVID-19. Higher risks of asthenozoospermia (odds ratio [OR] = 2.23, p < .001) and teratozoospermia (OR = 2.09, p = .03) were found among men who had an SARS-CoV-2 infection that lasted less than 30 days than among those without COVID-19. Collectively, after receiving SARS-CoV-2 vaccination, adverse but reversible semen parameters were observed in men recovering from COVID-19 over time. Recombinant protein vaccines and inactivated vaccine boosters should be recommended to all reproductive-age men.

New insights into kidney disease after COVID-19 infection and vaccination: histopathological and clinical findings

In addition to its pulmonary effects, coronavirus disease 2019 (COVID-19) has also been found to cause acute kidney injury (AKI), which has been linked to high mortality rates. In this review, we collected data from 20 clinical studies on post-COVID-19-related AKI and 97 cases of AKI associated with COVID-19 vaccination. Acute tubular injury was by far the most common finding in the kidneys of patients with COVID-19-related AKI. Among patients hospitalized for COVID-19, 34.0% developed AKI, of which 59.0%, 19.1% and 21.9% were Stages 1, 2 and 3, respectively. Though kidney disease and other adverse effects after COVID-19 vaccination overall appear rare, case reports have accumulated suggesting that COVID-19 vaccination may be associated with a risk of subsequent kidney disease. Among the patients with post-vaccination AKI, the most common pathologic findings include crescentic glomerulonephritis (29.9%), acute tubular injury (23.7%), IgA nephropathy (18.6%), antineutrophil cytoplasmic autoantibody-associated vasculitis (17.5%), minimal change disease (17.5%) and thrombotic microangiopathy (10.3%). It is important to note that crescentic glomerulonephritis appears to be more prevalent in patients who have newly diagnosed renal involvement. The proportions of patients with AKI Stages 1, 2 and 3 after COVID-19 vaccination in case reports were 30.9%, 22.7% and 46.4%, respectively. In general, clinical cases of new-onset and recurrent nephropathy with AKI after COVID-19 vaccination have a positive prognosis. In this article, we also explore the underlying pathophysiological mechanisms of AKI associated with COVID-19 infection and its vaccination by describing key renal morphological and clinical features and prognostic findings.

Genomic surveillance during the first two years of the COVID-19 pandemic - country experience and lessons learned from Türkiye

Background

Türkiye confirmed its first case of SARS-CoV-2 on March 11, 2020, coinciding with the declaration of the global COVID-19 pandemic. Subsequently, Türkiye swiftly increased testing capacity and implemented genomic sequencing in 2020. This paper describes Türkiye's journey of establishing genomic surveillance as a middle-income country with limited prior sequencing capacity and analyses sequencing data from the first two years of the pandemic. We highlight the achievements and challenges experienced and distill globally relevant lessons.

Methods

We tracked the evolution of the COVID-19 pandemic in Türkiye from December 2020 to February 2022 through a timeline and analysed epidemiological, vaccination, and testing data. To investigate the phylodynamic and phylogeographic aspects of SARS-CoV-2, we used Nextstrain to analyze 31,629 high-quality genomes sampled from seven regions nationwide.

Results

Türkiye's epidemiological curve, mirroring global trends, featured four distinct waves, each coinciding with the emergence and spread of variants of concern (VOCs). Utilizing locally manufactured kits to expand testing capacity and introducing variant-specific quantitative reverse transcription polymerase chain reaction (RT-qPCR) tests developed in partnership with a private company was a strategic advantage in Türkiye, given the scarcity and fragmented global supply chain early in the pandemic. Türkiye contributed more than 86,000 genomic sequences to global databases by February 2022, ensuring that Turkish data was reflected globally. The synergy of variant-specific RT-qPCR kits and genomic sequencing enabled cost-effective monitoring of VOCs. However, data analysis was constrained by a weak sequencing sampling strategy and fragmented data management systems, limiting the application of sequencing data to guide the public health response. Phylodynamic analysis indicated that Türkiye's geographical position as an international travel hub influenced both national and global transmission of each VOC despite travel restrictions.

Conclusion

This paper provides valuable insights into the testing and genomic surveillance systems adopted by Türkiye during the COVID-19 pandemic, proposing important lessons for countries developing national systems. The findings underscore the need for robust testing and sampling strategies, streamlined sample referral, and integrated data management with metadata linkage and data quality crucial for impactful epidemiological analysis. We recommend developing national genomic surveillance strategies to guide sustainable and integrated expansion of capacities built for COVID-19 and to optimize the effective utilization of sequencing data for public health action.

Increase in HIV reservoir and T cell immune response after CoronaVac vaccination in people living with HIV

Introduction

CoronaVac, an inactivated vaccine developed by Sinovac Life Sciences, has been widely used for protection against Coronavirus Disease 2019 (COVID-19). This study investigates its effect on the HIV reservoir and T cell repertoires in people living with HIV (PLWHs).

Methods

Blood samples were collected from fifteen PLWHs who were administered at least two doses of CoronaVac between April 2021 and February 2022. The levels of cell-associated HIV RNA (CA HIV RNA) and HIV DNA, as well as the T cell receptor (TCR) repertoire profiles, TCR clustering and TCRβ annotation, were studied.

Results

A significant increase was observed in CA HIV RNA at 2 weeks (431.5 ± 164.2 copies/106 cells, P = 0.039) and 12 weeks (330.2 ± 105.9 copies/106 cells, P = 0.019) after the second dose, when compared to the baseline (0 weeks) (73.6 ± 23.7 copies/106 cells). Various diversity indices of the TCRβ repertoire, including Shannon index, Pielou's evenness index, and Hvj Index, revealed a slight increase (P < 0.05) following CoronaVac vaccination. The proportion of overlapping TCRβ clonotypes increased from baseline (31.9 %) to 2 weeks (32.5 %) and 12 weeks (40.4 %) after the second dose. We also found that the breadth and depth of COVID-19-specific T cells increased from baseline (0.003 and 0.0035) to 12 weeks (0.0066 and 0.0058) post the second dose.

Conclusions

Our study demonstrated an initial increase in HIV reservoir and TCR repertoire diversity, as well as an expansion in the depth and breadth of COVID-19-specific T-cell clones among CoronaVac-vaccinated PLWHs. These findings provide important insights into the effects of COVID-19 vaccination in PLWHs.

Immune responses during COVID-19 breakthrough cases in vaccinated children and adolescents

Background

Vaccine effectiveness against SARS-CoV-2 infection has been somewhat limited due to the widespread dissemination of the Omicron variant, its subvariants, and the immune response dynamics of the naturally infected with the virus.

Methods

Twelve subjects between 3-17 years old (yo), vaccinated with two doses of CoronaVac®, were followed and diagnosed as breakthrough cases starting 14 days after receiving the second dose. Total IgGs against different SARS-CoV-2 proteins and the neutralizing capacity of these antibodies after infection were measured in plasma. The activation of CD4+ and CD8+ T cells was evaluated in peripheral blood mononuclear cells stimulated with peptides derived from the proteins from the wild-type (WT) virus and Omicron subvariants by flow cytometry, as well as different cytokines secretion by a Multiplex assay.

Results

2 to 8 weeks post-infection, compared to 4 weeks after 2nd dose of vaccine, there was a 146.5-fold increase in neutralizing antibody titers against Omicron and a 38.7-fold increase against WT SARS-CoV-2. Subjects showed an increase in total IgG levels against the S1, N, M, and NSP8 proteins of the WT virus. Activated CD4+ T cells showed a significant increase in response to the BA.2 subvariant (p<0.001). Finally, the secretion of IL-2 and IFN-γ cytokines showed a discreet decrease trend after infection in some subjects.

Conclusion

SARS-CoV-2 infection in the pediatric population vaccinated with an inactivated SARS-CoV-2 vaccine produced an increase in neutralizing antibodies against Omicron and increased specific IgG antibodies for different SARS-CoV-2 proteins. CD4+ T cell activation was also increased, suggesting a conserved cellular response against the Omicron subvariants, whereas Th1-type cytokine secretion tended to decrease.

Clinical Trial Registration

clinicaltrials.gov #NCT04992260.

The Equal Neutralizing Effectiveness of BNT162b2, ChAdOx1 nCoV-19, and Sputnik V Vaccines in the Palestinian Population

Since the beginning of the COVID-19 pandemic, different viral vector-based and mRNA vaccines directed against the SARS-CoV-2 "S" spike glycoprotein have been developed and have shown a good profile in terms of safety and efficacy. Nevertheless, an unbiased comparison of vaccination efficiency, including post-vaccination neutralizing activity, between the different vaccines remains largely unavailable. This study aimed to compare the efficacy of one mRNA (BNT162b2) and two non-replicating adenoviral vector vaccines (ChAdOx1 nCoV-19 and Sputnik V) in a cohort of 1120 vaccinated Palestinian individuals who received vaccines on an availability basis and which displayed a unique diversity of genetic characteristics. We assessed the level of anti-S antibodies and further determined the antibody neutralizing activity in 261 of those individuals vaccinated with BNT162b2a (121), ChAdOx1 (72) or Sputnik V (68). Our results showed no significant difference in the distribution of serum-neutralizing activity or S-antibody serum levels for the three groups of vaccines, proving equivalence in efficacy for the three vaccines under real-life conditions. In addition, none of the eight demographic parameters tested had an influence on vaccination efficacy. Regardless of the vaccine type, the vaccination campaign ultimately played a pivotal role in significantly reducing the morbidity and mortality associated with COVID-19 in Palestine.

Effect of Corticosteroid on Immunogenicity of SARS-CoV-2 Vaccines in Patients With Solid Cancer

PURPOSE

Corticosteroids are known to diminish immune response ability, which is generally used in routine premedication for chemotherapy. The intersecting of timeframe between the corticosteroid's duration of action and peak COVID-19 vaccine efficacy could impair vaccine immunogenicity. Thus, inquiring about corticosteroids affecting the efficacy of vaccines to promote effective immunity in this population is needed.

METHODS

This was a prospective longitudinal observational cohort study that enrolled patients with solid cancer classified into dexamethasone- and nondexamethasone-receiving groups. All participants were immunized with two doses of ChAdOx1 nCoV-19 or CoronaVac vaccines. This study's purpose was to compare corticosteroid's effect on immunogenicity responses to the SARS-CoV-2 S protein in patients with cancer after two doses of COVID-19 vaccine in the dexamethasone and nondexamethasone group. Secondary outcomes included the postimmunization anti-spike (S) immunoglobin G (IgG) seroconversion rate, the association of corticosteroid dosage, time duration, and immunogenicity level.

RESULTS

Among the 161 enrolled patients with solid cancer, 71 and 90 were in the dexamethasone and nondexamethasone groups, respectively. The median anti-S IgG titer after COVID-19 vaccination in the dexamethasone group was lower than that in the nondexamethasone group with a statistically significant difference (47.22 v 141.09 U/mL, P = .035). The anti-S IgG seroconversion rate was also significantly lower in the dexamethasone group than in the nondexamethasone group (93.83% v 80.95%, P = .023). The lowest median anti-SARS-CoV-2 IgG titer level at 7.89 AU/mL was observed in patients with the highest dose of steroid group (≥37 mg of dexamethasone cumulative dose throughout the course of chemotherapy [per course]) and patients who were injected with COVID-19 vaccines on the same day of receiving dexamethasone, 25.41 AU/mL.

CONCLUSION

Patients with solid cancer vaccinated against COVID-19 disease while receiving dexamethasone had lower immunogenicity responses than those who got vaccines without dexamethasone. The direct association between the immunogenicity level and steroid dosage, as well as length of duration from vaccination to dexamethasone, was observed.

Development of Anti-idiotypic Monoclonal Antibody Mimicking SARS-CoV-2 Receptor Binding Domain

Using the hybridoma technique, we developed a panel of anti-idiotypic monoclonal antibodies (aId-mAb) that mimic The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Receptor-Binding Domain (RBD) molecule against Fragment antigen-binding (Fab) of anti-SARS-CoV-2 (S1, RBD) antibodies. Investigated the in vivo and in vitro effects of these aId-mAbs we developed and examined their antigenic mimicry abilities. Among these 12 antibodies, 6 aId-mAbs (designated FY1B4, FY2A6, H9F3, E6G7, FY7E11, and FY8H3) were selected for further characterization in a series of experiments. First, competitive receptor binding assay results confirmed that six aId-mAbs could specifically bind to the ACE2 receptor in target cells and block the interaction between the RBD molecule and the ACE receptor. Moreover, we examined the immunological activities of these aId-mAbs in female BALB/c and showed that E6G7, H7E11, and H8H3 aId-mAbs induce an antibody response by mimicking RBD and stimulating the immune system. It is considered that these three aId-mAbs will be evaluated as SARS-CoV-2 vaccine candidate molecules in future studies.

Second booster dose improves antibody neutralization against BA.1, BA.5 and BQ.1.1 in individuals previously immunized with CoronaVac plus BNT162B2 booster protocol

Introduction

SARS-CoV-2 vaccines production and distribution enabled the return to normalcy worldwide, but it was not fast enough to avoid the emergence of variants capable of evading immune response induced by prior infections and vaccination. This study evaluated, against Omicron sublineages BA.1, BA.5 and BQ.1.1, the antibody response of a cohort vaccinated with a two doses CoronaVac protocol and followed by two heterologous booster doses.

Methods

To assess vaccination effectiveness, serum samples were collected from 160 individuals, in 3 different time points (9, 12 and 18 months after CoronaVac protocol). For each time point, individuals were divided into 3 subgroups, based on the number of additional doses received (No booster, 1 booster and 2 boosters), and a viral microneutralization assay was performed to evaluate neutralization titers and seroconvertion rate.

Results

The findings presented here show that, despite the first booster, at 9m time point, improved neutralization level against omicron ancestor BA.1 (133.1 to 663.3), this trend was significantly lower for BQ.1.1 and BA.5 (132.4 to 199.1, 63.2 to 100.2, respectively). However, at 18m time point, the administration of a second booster dose considerably improved the antibody neutralization, and this was observed not only against BA.1 (2361.5), but also against subvariants BQ.1.1 (726.1) and BA.5 (659.1). Additionally, our data showed that, after first booster, seroconvertion rate for BA.5 decayed over time (93.3% at 12m to 68.4% at 18m), but after the second booster, seroconvertion was completely recovered (95% at 18m).

Discussion

Our study reinforces the concerns about immunity evasion of the SARS-CoV-2 omicron subvariants, where BA.5 and BQ.1.1 were less neutralized by vaccine induced antibodies than BA.1. On the other hand, the administration of a second booster significantly enhanced antibody neutralization capacity against these subvariants. It is likely that, as new SARS-CoV-2 subvariants continue to emerge, additional immunizations will be needed over time.

Boosting the immunogenicity of the CoronaVac SARS-CoV-2 inactivated vaccine with Huoxiang Suling Shuanghua Decoction: a randomized, double-blind, placebo-controlled study

Introduction

In light of the public health burden of the COVID-19 pandemic, boosting the safety and immunogenicity of COVID-19 vaccines is of great concern. Numerous Traditional Chinese medicine (TCM) preparations have shown to beneficially modulate immunity. Based on pilot experiments in mice that showed that supplementation with Huoxiang Suling Shuanghua Decoction (HSSD) significantly enhances serum anti-RBD IgG titers after inoculation with recombinant SARS-CoV-2 S-RBD protein, we conducted this randomized, double-blind, placebo-controlled clinical trial aimed to evaluate the potential immunogenicity boosting effect of oral HSSD after a third homologous immunization with Sinovac's CoronaVac SARS-CoV-2 (CVS) inactivated vaccine.

Methods

A total of 70 participants were randomly assigned (1:1 ratio) to receive a third dose of CVS vaccination and either oral placebo or oral HSSD for 7 days. Safety aspects were assessed by recording local and systemic adverse events, and by blood and urine biochemistry and liver and kidney function tests. Main outcomes evaluated included serum anti-RBD IgG titer, T lymphocyte subsets, serum IgG and IgM levels, complement components (C3 and C4), and serum cytokines (IL-6 and IFN-γ). In addition, metabolomics technology was used to analyze differential metabolite expression after supplementation with HSSD.

Results

Following a third CVS vaccination, significantly increased serum anti-RBD IgG titer, reduced serum IL-6 levels, increased serum IgG, IgM, and C3 and C4 levels, and improved cellular immunity, evidenced by reduce balance deviations in the distribution of lymphocyte subsets, was observed in the HSSD group compared with the placebo group. No serious adverse events were recorded in either group. Serum metabolomics results suggested that the mechanisms by which HSSD boosted the immunogenicity of the CVS vaccine are related to differential regulation of purine metabolism, vitamin B6 metabolism, folate biosynthesis, arginine and proline metabolism, and steroid hormone biosynthesis.

Conclusion

Oral HSSD boosts the immunogenicity of the CVS vaccine in young and adult individuals. This trial provides clinical reference for evaluation of TCM immunomodulators to improve the immune response to COVID-19 vaccines.

COVID-19 vaccination affects short-term anti-coagulation levels in warfarin treatment

Vaccines against SARS-CoV-2 have been recommended across the world, yet no study has investigated whether COVID-19 vaccination influences short-term warfarin anti-coagulation levels. Patients on stable warfarin treatment who received anti-SARS-CoV-2 vaccination were prospectively enrolled and followed up for three months. INR values less than 10 days before vaccination (baseline), 3-5 days (short-term) and 6-14 days (medium-term) after vaccination were recorded as INR0, INR1, and INR2, respectively. The variations of INR values within individuals were compared, and the linear mixed effect model was used to evaluate the variations of INR values at different time points. Logistic regression analysis was performed to determine covariates related to INR variations after COVID-19 vaccination. Vaccination safety was also monitored. There was a significant difference in INR values between INR0 and INR1 (2.15 vs. 2.26, p = 0.003), yet no marked difference was found between INR0 and INR2. The linear mixed effect model also demonstrated that INR variation was significant in short-term but not in medium-term or long-term period after vaccination. Logistic regression analysis showed that no investigated covariates, including age, vaccine dose, genetic polymorphisms of VKORC1 and CYP2C9 etc., were associated with short-term INR variations. Two patients (2.11%) reported gingival hemorrhage in the short-term due to increased INR values. The overall safety of COVID-19 vaccines for patients on warfarin was satisfying. COVID-19 vaccines may significantly influence warfarin anticoagulation levels 3-5 days after vaccination. We recommend patients on warfarin to perform at least one INR monitoring within the first week after COVID-19 vaccination.

Intranasal SARS-CoV-2 RBD decorated nanoparticle vaccine enhances viral clearance in the Syrian hamster model

Multiple vaccines have been developed and licensed for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). While these vaccines reduce disease severity, they do not prevent infection. To prevent infection and limit transmission, vaccines must be developed that induce immunity in the respiratory tract. Therefore, we performed proof-of-principle studies with an intranasal nanoparticle vaccine against SARS-CoV-2. The vaccine candidate consisted of the self-assembling 60-subunit I3-01 protein scaffold covalently decorated with the SARS-CoV-2 receptor-binding domain (RBD) using the SpyCatcher-SpyTag system. We verified the intended antigen display features by reconstructing the I3-01 scaffold to 3.4 A using cryogenicelectron microscopy. Using this RBD-grafted SpyCage scaffold (RBD + SpyCage), we performed two intranasal vaccination studies in the "gold-standard" pre-clinical Syrian hamster model. The initial study focused on assessing the immunogenicity of RBD + SpyCage combined with the LTA1 intranasal adjuvant. These studies showed RBD + SpyCage vaccination induced an antibody response that promoted viral clearance but did not prevent infection. Inclusion of the LTA1 adjuvant enhanced the magnitude of the antibody response but did not enhance protection. Thus, in an expanded study, in the absence of an intranasal adjuvant, we evaluated if covalent bonding of RBD to the scaffold was required to induce an antibody response. Covalent grafting of RBD was required for the vaccine to be immunogenic, and animals vaccinated with RBD + SpyCage more rapidly cleared SARS-CoV-2 from both the upper and lower respiratory tract. These findings demonstrate the intranasal SpyCage vaccine platform can induce protection against SARS-CoV-2 and, with additional modifications to improve immunogenicity, is a versatile platform for the development of intranasal vaccines targeting respiratory pathogens.IMPORTANCEDespite the availability of efficacious COVID vaccines that reduce disease severity, SARS-CoV-2 continues to spread. To limit SARS-CoV-2 transmission, the next generation of vaccines must induce immunity in the mucosa of the upper respiratory tract. Therefore, we performed proof-of-principle, intranasal vaccination studies with a recombinant protein nanoparticle scaffold, SpyCage, decorated with the RBD of the S protein (SpyCage + RBD). We show that SpyCage + RBD was immunogenic and enhanced SARS-CoV-2 clearance from the nose and lungs of Syrian hamsters. Moreover, covalent grafting of the RBD to the scaffold was required to induce an immune response when given via the intranasal route. These proof-of-concept findings indicate that with further enhancements to immunogenicity (e.g., adjuvant incorporation and antigen optimization), the SpyCage scaffold has potential as a versatile, intranasal vaccine platform for respiratory pathogens.

Autoimmune response after SARS-CoV-2 infection and SARS-CoV-2 vaccines

The complicated relationships between autoimmunity, COVID-19, and COVID-19 vaccinations are described, giving insight into their intricacies. Antinuclear antibodies (ANA), anti-Ro/SSA, rheumatoid factor, lupus anticoagulant, and antibodies against interferon (IFN)-I have all been consistently found in COVID-19 patients, indicating a high prevalence of autoimmune reactions following viral exposure. Furthermore, the discovery of human proteins with structural similarities to SARS-CoV-2 peptides as possible autoantigens highlights the complex interplay between the virus and the immune system in initiating autoimmunity. An updated summary of the current status of COVID-19 vaccines is presented. We present probable pathways underpinning the genesis of COVID-19 autoimmunity, such as bystander activation caused by hyperinflammatory conditions, viral persistence, and the creation of neutrophil extracellular traps. These pathways provide important insights into the development of autoimmune-related symptoms ranging from organ-specific to systemic autoimmune and inflammatory illnesses, demonstrating the wide influence of COVID-19 on the immune system.

Pathophysiological, immunological, and inflammatory features of long COVID

The COVID-19 pandemic continues to cause severe global disruption, resulting in significant excess mortality, overwhelming healthcare systems, and imposing substantial social and economic burdens on nations. While most of the attention and therapeutic efforts have concentrated on the acute phase of the disease, a notable proportion of survivors experience persistent symptoms post-infection clearance. This diverse set of symptoms, loosely categorized as long COVID, presents a potential additional public health crisis. It is estimated that 1 in 5 COVID-19 survivors exhibit clinical manifestations consistent with long COVID. Despite this prevalence, the mechanisms and pathophysiology of long COVID remain poorly understood. Alarmingly, evidence suggests that a significant proportion of cases within this clinical condition develop debilitating or disabling symptoms. Hence, urgent priority should be given to further studies on this condition to equip global public health systems for its management. This review provides an overview of available information on this emerging clinical condition, focusing on the affected individuals' epidemiology, pathophysiological mechanisms, and immunological and inflammatory profiles.

Safety, immunogenicity and protective effectiveness of heterologous boost with a recombinant COVID-19 vaccine (Sf9 cells) in adult recipients of inactivated vaccines

Vaccines have proven effective in protecting populations against COVID-19, including the recombinant COVID-19 vaccine (Sf9 cells), the first approved recombinant protein vaccine in China. In this positive-controlled trial with 85 adult participants (Sf9 cells group: n = 44; CoronaVac group: n = 41), we evaluated the safety, immunogenicity, and protective effectiveness of a heterologous boost with the Sf9 cells vaccine in adults who had been vaccinated with the inactivated vaccine, and found a post-booster adverse events rate of 20.45% in the Sf9 cells group and 31.71% in the CoronaVac group (p = 0.279), within 28 days after booster injection. Neither group reported any severe adverse events. Following the Sf9 cells vaccine booster, the geometric mean titer (GMT) of binding antibodies to the receptor-binding domain of prototype SARS-CoV-2 on day 28 post-booster was significantly higher than that induced by the CoronaVac vaccine booster (100,683.37 vs. 9,451.69, p < 0.001). In the Sf9 cells group, GMTs of neutralizing antibodies against pseudo SARS-CoV-2 viruses (prototype and diverse variants of concern [VOCs]) increased by 22.23-75.93 folds from baseline to day 28 post-booster, while the CoronaVac group showed increases of only 3.29-10.70 folds. Similarly, neutralizing antibodies against live SARS-CoV-2 viruses (prototype and diverse VOCs) increased by 68.18-192.67 folds on day 14 post-booster compared with the baseline level, significantly greater than the CoronaVac group (19.67-37.67 folds). A more robust Th1 cellular response was observed with the Sf9 cells booster on day 14 post-booster (mean IFN-γ+ spot-forming cells per 2 × 105 peripheral blood mononuclear cells: 26.66 vs. 13.59). Protective effectiveness against symptomatic COVID-19 was approximately twice as high in the Sf9 cells group compared to the CoronaVac group (68.18% vs. 36.59%, p = 0.004). Our study findings support the high protective effectiveness of heterologous boosting with the recombinant COVID-19 vaccine (Sf9 cells) against symptomatic COVID-19 of diverse SARS-CoV-2 variants of concern, while causing no apparent safety concerns.

SARS-CoV-2 vaccination and semen quality: a study based on sperm donor candidate data in southwest China

Background

The coronavirus disease 2019 (COVID-19) pandemic has been a global health crisis and continues to pose risk to population health at the present. Vaccination against this disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has become a public health priority worldwide. Yet, limited information is available on the potential impact of such vaccines on human fertility.

Methods

To examine the relationship between COVID-19 vaccination and male fertility, we conducted an observational study on sperm donor candidates in China who received Chinese COVID-19 vaccines between January 1, 2020 to December 31, 2021.

Results

A total of 2,955 semen samples from 564 individuals were assessed along with vaccination information. Statistical analyses were conducted on both the entire study population and the subgroup of individuals who provided repeated semen samples before and after vaccination. While motility related parameters [progressive rate, curvilinear velocity (VCL), average path velocity (VAP), straight-line velocity (VSL), wobble (WOB), straightness (STR), linearity (LIN), amplitude of lateral head displacement (ALH), beat-cross frequency (BCF)] exhibited statistically significant difference before and after vaccination based on Welch two-sample test, mixed effects regression results based on repeated measures from the same individuals indicated that vaccination was not statistically associated with sperm quality parameters except for VCL, VAP, and VSL. Individual variability was the key determinant of sperm quality variance, with contribution ranging from 19% to 82%.

Conclusions

Findings from our study could help to enhance current understanding of male reproductive health in the context of the global pandemic.

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.

COVID-19 vaccination willingness among people living with HIV in Shijiazhuang, China: a cross-sectional survey

Objectives

The COVID-19 pandemic imposed an enormous disease and economic burden worldwide. SARS-CoV-2 vaccination is essential to containing the pandemic. People living with HIV (PLWH) may be more vulnerable to severe COVID-19 outcomes; thus, understanding their vaccination willingness and influencing factors is helpful in developing targeted vaccination strategies.

Methods

A cross-sectional study was conducted between 15 June and 30 August 2022 in Shijiazhuang, China. Variables included socio-demographic characteristics, health status characteristics, HIV-related characteristics, knowledge, and attitudes toward COVID-19 vaccination and COVID-19 vaccination status. Multivariable logistic regression was used to confirm factors associated with COVID-19 vaccination willingness among PLWH.

Results

A total of 1,428 PLWH were included, with a 90.48% willingness to receive the COVID-19 vaccination. PLWH were more unwilling to receive COVID-19 vaccination for those who were female or had a fair/poor health status, had an allergic history and comorbidities, were unconvinced and unsure about the effectiveness of vaccines, were unconvinced and unsure about the safety of vaccines, were convinced and unsure about whether COVID-19 vaccination would affect ART efficacy, or did not know at least a type of domestic COVID-19 vaccine. Approximately 93.00% of PLWH have received at least one dose of the COVID-19 vaccine among PLWH, and 213 PLWH (14.92%) reported at least one adverse reaction within 7 days.

Conclusion

In conclusion, our study reported a relatively high willingness to receive the COVID-19 vaccination among PLWH in Shijiazhuang. However, a small number of PLWH still held hesitancy; thus, more tailored policies or guidelines from the government should be performed to enhance the COVID-19 vaccination rate among PLWH.

Safety and efficacy of COVID-19 vaccine immunization during pregnancy in 1024 pregnant women infected with the SARS-CoV-2 Omicron virus in Shanghai, China

Background

Large sample of pregnant women vaccinated with COVID-19 vaccine has not been carried out in China. The objective of this study was to evaluate the safety and effectiveness of COVID-19 inactivated vaccine in pregnant women infected with the SARS-CoV-2 Omicron variant.

Methods

A total of 1,024 pregnant women and 120 newborns were enrolled in this study. 707 pregnant women received one to three doses of the inactivated COVID-19 vaccine, and 317 unvaccinated patients served as the control group. A comparison was made between their clinical and laboratory data at different stages of pregnancy.

Results

The incidence rate of patients infected with Omicron variant in the first, the second, and the third trimesters of pregnancy was 27.5%, 27.0%, and 45.5% in patients during, respectively. The corresponding length of hospital stay was 8.7 ± 3.3 days, 9.5 ± 3.3 days, and 11 ± 4.3 days, respectively. The hospitalization time of pregnant women who received 3 doses of vaccine was (8.8 ± 3.3) days, which was significantly shorter than that of non-vaccinated women (11.0 ± 3.9) days. (P<0.0001). The positive rate of SARS-CoV-2 IgG in patients in the early stage of pregnancy was 28.8%, while that in patients in the late stage of pregnancy was 10.3%. However, three-doses of vaccination significantly increased the SARS-CoV-2 IgG positive rate to 49.5%. The hospitalization time of SARS-CoV-2 IgG-positive patients was shorter than that of negative patients (9.9 ± 3.5 days), which was 7.4 ± 2.0 days. 12.2% of vaccinated women experienced mild adverse reactions, manifested as fatigue (10.6%) and loss of appetite (1.6%). The vaccination of mother did not affect her choice of future delivery mode and the Apgar score of their newborn. All newborns tested negative for SARS-CoV-2 nucleic acid, as well as for IgG and IgM antibodies.

Conclusions

Women in the third trimester of pregnancy are highly susceptible to infection with the Omicron strain. The vaccination of pregnant women with COVID-19 vaccine can accelerate the process of eliminating SARS-CoV-2 virus, and is considered safe for newborns. The recommended vaccination includes three doses.

Immunogenicity, safety and consistency of seven lots of an inactivated COVID-19 vaccine in healthy children and adolescents: a randomized, double-blind, controlled, phase IV clinical trial

Background

CoronaVac has been authorized worldwide for preventing coronavirus disease 2019. Information on the safety, immunogenicity and consistency of different lots and workshops of CoronaVac is presented here.

Methods

In this randomized, double-blind, phase IV clinical trial in healthy children and adolescents aged 3-17 years, we aimed to assess the lot-to-lot and workshop-to-workshop consistency, as well as immunogenicity and safety of seven lots of commercial-scale CoronaVac from three workshops. Eligible participants were enrolled into three age cohorts (3-5, 6-11 and 12-17 years). Within each cohort, participants were randomly assigned to seven groups to receive two doses of CoronaVac, with four weeks apart. Serum samples were collected before the first dose and 28 days after the second dose for neutralizing antibody testing. The primary objective was to evaluate the consistency of immune response among different lots within workshop 2 or 3, as well as among different workshops. The primary endpoint was geometric mean titer (GMT) of neutralizing antibody at 28 days after full-course vaccination.

Results

Between July 27th and November 19th, 2021, a total of 2,520 eligible participants were enrolled. Results showed that 95% confidence intervals (CIs) of GMT ratios for all comparative groups among different lots or workshops were within the equivalence criteria of [0.67, 1.5]. The GMT and seroconversion rate for all participants were 126.42 (95%CI: 121.82, 131.19) and 99.86% (95%CI: 99.59%, 99.97%) at 28 days after two-dose vaccination. The incidences of adverse reactions were similar among seven lots, and most adverse reactions were mild in Grade 1, with no serious adverse event.

Conclusion

CoronaVac is well-tolerated and can elicit a good immune response among children and adolescents. Lot-to-lot consistency results indicate stable manufacturing of commercial-scale CoronaVac.

Effectiveness of Vaccines and Antiviral Drugs in Preventing Severe and Fatal COVID-19, Hong Kong

We compared the effectiveness and interactions of molnupiravir and nirmatrelvir/ritonavir and 2 vaccines, CoronaVac and Comirnaty, in a large population of inpatients with COVID-19 in Hong Kong. Both the oral antiviral drugs and vaccines were associated with lower risks for all-cause mortality and progression to serious/critical/fatal conditions (study outcomes). No significant interaction effects were observed between the antiviral drugs and vaccinations; their joint effects were additive. If antiviral drugs were prescribed within 5 days of confirmed COVID-19 diagnosis, usage was associated with lower risks for the target outcomes for patients >60, but not <60, years of age; no significant clinical benefit was found if prescribed beyond 5 days. Among patients >80 years of age, 3-4 doses of Comirnaty vaccine were associated with significantly lower risks for target outcomes. Policies should encourage COVID-19 vaccination, and oral antivirals should be made accessible to infected persons within 5 days of confirmed diagnosis.

A Retrospective Study on COVID-19 Infections Caused by Omicron Variant with Clinical, Epidemiological, and Viral Load Evaluations in Breakthrough Infections

Purpose: To explore the clinical, epidemiological, and viral load characteristics of COVID-19 caused by the omicron variant. Methods: Based on the COVID-19 epidemic caused by SARS-CoV-2 Omicron BA.2 broke out in Shanghai, China. To analyze whether there is any association between clinical symptoms and viral load of COVID-19 with age, sex, and combined disease and whether the clinical symptoms and viral load are associated with vaccine-breakthrough infections. Results: The most common symptoms were cough, expectoration, and fatigue, which were more common in women than males (p < 0.001). The average viral clearance time in the > 75 years group was the longest (6.64 days). The viral load in the 60-75 years group was significantly higher than that in the other groups (p < 0.001). The 18-45 years old group had the most clinical symptoms at admission (45.39%). The days of nucleic acid-negative conversion, average viral load, highest viral load, and clinical symptoms in comorbid chronic disease patients are longer (p < 0.001). The average and highest viral loads in the unvaccinated group were longer than those in the vaccine breakthrough infection groups (p < 0.001). However, the clinical symptoms in the vaccine breakthrough infection group were significantly more severe than those in the unvaccinated group (p < 0.001). Conclusions: We found that female patients, the elderly, and those with underlying comorbidities had longer clinical positive symptoms and viral loads. Although vaccination may not reduce clinical symptoms, it can shorten the viral load and the time required for virus clearance.

Impaired antibody response to inactivated COVID-19 vaccines in hospitalized patients with type 2 diabetes

Patients with type 2 diabetes (T2D) are at an increased risk of morbidity and mortality of coronavirus disease 2019 (COVID-19). Data on the antibody response to COVID-19 vaccines in T2D patients are less studied. This study aimed to evaluate IgG antibody response to inactivated COVID-19 vaccines in hospitalized T2D patients. Hospitalized patients with no history of COVID-19 and received two doses of inactivated COVID-19 vaccines (Sinopharm or CoronaVac) were included in this study from March to October 2021. SARS-CoV-2 specific IgG antibodies were measured 14-60 days after the second vaccine dose. A total of 209 participants, 96 with T2D and 113 non-diabetes patients, were included. The positive rate and median titer of IgG antibody against receptor-binding domain (anti-RBD) of spike (S) protein of SARS-CoV-2 in T2D group were lower than in control group (67.7% vs 83.2%, p = .009; 12.93 vs 17.42 AU/ml, p = .014) respectively. Similarly, seropositivity and median titers of IgG antibody against the nucleocapsid (N) and S proteins of SARS-CoV-2 (anti-N/S) in T2D group were lower than in control group (68.8% vs 83.2%, p = .032; 18.81 vs 29.57 AU/mL, p = .012) respectively. After adjustment for age, sex, BMI, vaccine type, days after the second vaccine dose, hypertension, kidney disease, and heart disease, T2D was identified as an independent risk factor for negative anti-RBD and anti-N/S seropositivity, odd ratio 0.42 (95% confidence interval 0.19, 0.89) and 0.42 (95% CI 0.20, 0.91), respectively. T2D is associated with impaired antibody response to inactivated COVID-19 vaccine.

Is vaccine hesitancy related to mental health after the adjustment of the zero-COVID-19 strategy in the elderly? A mediation analysis in China

With the global Omicron pandemic and the adjustment of the zero-coronavirus disease 2019 (zero-COVID-19) strategy in China, there is a critical need to improve vaccination rates among older adults while addressing the mental health issues associated with vaccination. This study investigated levels of COVID-19-related anxiety, depression, benefit finding, and fear in older adults and explored the relationship between vaccine hesitancy, sociodemographic factors, and mental health. Participants aged 60 and older (n = 658) were recruited from several cities in the eastern, central, and western China regions. Of these, 347 exhibited vaccine hesitancy. The effects of residence, education, health status, and COVID-19 vaccination on anxiety/depression/benefit-finding were found to be mediated/suppressed by vaccine hesitancy. Additionally, in investigating psychological antecedents, older people without vaccine hesitancy showed higher confidence, lower complacency, fewer constraints, and a greater sense of collective responsibility. This study advances our understanding of mental health differences in anxiety, depression, and benefit-finding across sociodemographic characteristics. It is essential to improve population confidence related to vaccines, accessibility to vaccination services, and responsibility to mitigate vaccine hesitancy while paying close attention to the mental health associated with vaccination in older adults.

Awareness of and attitude toward COVID-19 vaccination among individuals with COPD and the strategies to overcome vaccine hesitation: A mini review

Coronavirus Disease 2019 (COVID-19) vaccines have a protective effect on individuals with chronic obstructive pulmonary disease (COPD), preventing them from developing severe illnesses and reducing the risk of hospitalization and mortality. However, the coverage rate of COVID-19 vaccination among this population is not satisfactory, which is associated with their lack of awareness of and negative attitudes toward COVID-19 vaccination, that is, vaccine hesitancy. We reviewed recent literatures on the vaccination status of COPD patients and vaccine hesitancy, described the factors related to vaccine hesitancy among COPD patients, and proposed strategies to improve the vaccine coverage, such as providing accurate and consistent vaccine information to the public, patient health education program, improving self-management capabilities, easy access to vaccination service, etc., which can hopefully help to improve patients' ability to cope with SARS-CoV-2 infection and reduce the COVID-19 related mortality.

COVISHIELD vaccine-induced thyroiditis: a case report

BACKGROUND

The rapid development of coronavirus disease 2019 vaccines during the pandemic has left their long-term effects largely unknown. Instances of autoimmune and subacute thyroiditis showing features of autoimmune/inflammatory syndrome induced by adjuvants have been reported post-vaccination. This case report aims to highlight the autoimmune/inflammatory syndrome induced by adjuvants syndrome after coronavirus disease 2019 vaccination, drawing attention to a possible connection with thyroid dysfunction and urging for further thorough research.

CASE PRESENTATION

We present a case of thyroiditis induced by the COVISHIELD vaccine in a 37-year-old Indian woman. An apparently normal and healthy adult woman developed neck pain and easy fatigability 2 weeks after the second dose of COVISHIELD, which gradually increased and was associated with irritability, decreased sleep, excessive sweating, tremor, palpitation, and weight loss. She presented to the outpatient department after 1 week of symptoms and was evaluated with laboratory tests and imaging. She was diagnosed with thyroiditis due to the coronavirus disease 2019 vaccine and was treated with propranolol.

CONCLUSION

This case report adds to the growing evidence of coronavirus disease 2019 vaccine-related thyroid issues. The development of thyroiditis is rare and underreported post-coronavirus disease 2019 vaccination; hence, research to evaluate the association of coronavirus disease 2019 vaccines with thyroid dysfunction needs to be done in the future.

The disparity in hesitancy toward COVID-19 vaccination between older individuals in nursing homes and those in the community in Taizhou, China

PURPOSE

Older individuals are priority coronavirus disease 2019 (COVID-19) vaccine recipients. Our aim was to investigate the prevalence of and factors influencing vaccine hesitancy in older individuals living in nursing homes and communities.

METHODS

A self-administered COVID-19 vaccine hesitancy survey was conducted from September 2021 to December 2021 among people aged ≥ 60 years in eight nursing homes (382 participants) and the community (112 participants) in Taizhou, China. The response rate was 72.1% (382/530) for older adults in nursing homes and 68.7% (112/163) for older adults in the community.

RESULTS

We found that 58.1% of the older individuals in nursing homes and 36.6% of those in the community were hesitant to receive the COVID-19 vaccine and that there was a statistically significant difference (P < 0.001). Multiple logistic regression results indicated that the main factors influencing hesitation among the older individuals in nursing homes were being male (Odds Ratio (OR) = 1.67, 95% Confidence Interval (CI): 1.01-2.76); their cognitive level, including having a high perceived risk of COVID-19 infection (OR = 3.06, 95% CI: 1.73-5.43) or the perception of low vaccine safety (OR = 3.08, 95% CI: 1.545- 6.145); anxiety (OR = 3.43, 95% CI: 1.96-5.99); and no previous influenza vaccination (OR = 1.82, 95% CI: 1.13-2.93); whereas those for older individuals in the community were comorbid chronic diseases (OR = 3.13, 95% CI: 1.11- 8.78) and community workers not recommending the vaccine (OR = 8.223, 95% CI: 1.77-38.27).

CONCLUSION

The proportion of older individuals in nursing homes who were hesitant to receive the COVID-19 vaccine was significantly higher than for older individuals in the community. Targeted measures should be implemented to reduce vaccine hesitancy and improve vaccination rates in response to the special environment of nursing homes and the characteristics of this population.

RBD-specific antibody response after two doses of different SARS-CoV-2 vaccines during the mass vaccination campaign in Mongolia

The SARS-CoV-2 vaccination campaign began in February 2021 and achieved a high rate of 62.7% of the total population fully vaccinated by August 16, 2021, in Mongolia. We aimed to assess the initial protective antibody production after two doses of a variety of types of SARS-CoV-2 vaccines in the Mongolian pre-vaccine antibody-naïve adult population. This prospective study was conducted from March-April to July-August of 2021. All participants received one of the four government-proposed COVID-19 vaccines including Pfizer/BioNTech (BNT162b2), AstraZeneca (ChAdOx1-S), Sinopharm (BBIBP-CorV), and Sputnik V (Gam-COVID-Vac). Before receiving the first shot, anti-SARS-CoV-2 S-RBD human IgG titers were measured in all participants (n = 1833), and titers were measured 21-28 days after the second shot in a subset of participants (n = 831). We found an overall average protective antibody response of 84.8% (705 of 831 vaccinated) in 21-28 days after two doses of the four types of COVID-19 vaccines. Seropositivity and titer of protective antibodies produced after two shots of vaccine were associated with the vaccine types, age, and residence of vaccinees. Seropositivity rate varied significantly between vaccine types, 80.0% (28 of 35) for AstraZeneca ChAdOx1-S; 97.0% (193 of 199) for Pfizer BNT162b2; 80.7% (474 of 587) for Sinopharm BBIBP-CorV, and 100.0% (10 of 10) for Sputnik V Gam-COVID-Vac, respectively. Immunocompromised vaccinees with increased risk for developing severe COVID-19 disease had received the Pfizer vaccine and demonstrated a high rate of seropositivity. A high geometric mean titer (GMT) was found in vaccinees who received BNT162b2, while vaccinees who received ChAdOx1-S, Sputnik V, and BBIBP-CorV showed a lower GMT. In summary, we observed first stages of the immunization campaign against COVID-19 in Mongolia have been completed successfully, with a high immunogenicity level achieved among the population with an increased risk for developing severe illness.

Safety and immunogenicity of an inactivated SARS-CoV-2 vaccine (FAKHRAVAC®) in healthy adults aged 18-55 years: Randomized, double-blind, placebo-controlled, phase I clinical trial

Background

The FAKHRAVAC®, an inactivated SARS-CoV-2 vaccine, was assessed for safety and immunogenicity.

Methods and findings

In this double-blind, placebo-controlled, phase I trial, we randomly assigned 135 healthy adults between 18 and 55 to receive vaccine strengths of 5 or 10 μg/dose or placebo (adjuvant only) in 0-14 or 0-21 schedules. This trial was conducted in a single center in a community setting. The safety outcomes in this study were reactogenicity, local and systemic adverse reactions, abnormal laboratory findings, and Medically Attended Adverse Events (MAAE). Immunogenicity outcomes include serum neutralizing antibody activity and specific IgG antibody levels.The most frequent local adverse reaction was tenderness (28.9%), and the most frequent systemic adverse reaction was headache (9.6%). All adverse reactions were mild, occurred at a similar incidence in all six groups, and were resolved within a few days. In the 10-µg/dose vaccine group, the geometric mean ratio for neutralizing antibody titers at two weeks after the second injection compared to the placebo group was 9.03 (95% CI: 3.89-20.95) in the 0-14 schedule and 11.77 (95% CI: 2.77-49.94) in the 0-21 schedule. The corresponding figures for the 5-µg/dose group were 2.74 (1.2-6.28) and 5.2 (1.63-16.55). The highest seroconversion rate (four-fold increase) was related to the 10-µg/dose group (71% and 67% in the 0-14 and 0-21 schedules, respectively).

Conclusions

FAKHRAVAC® is safe and induces a strong humoral immune response to the SARS-CoV-2 virus at 10-µg/dose vaccine strength in adults aged 18-55. This vaccine strength was used for further assessment in the phase II trial.Trial registrationThis study is registered with https://www.irct.ir; IRCT20210206050259N1.

Monitoring of antibody levels in healthcare workers after inactivated coronavirus disease 19 vaccination

OBJECTIVE

Because of the coronavirus disease 19 pandemic, studies on vaccination are being conducted in our country as well as across the world. In this study, the antibody levels in healthcare workers vaccinated with two doses of inactivated vaccine and the factors affecting these levels were investigated.

METHODS

Randomly selected volunteers from healthcare workers, who had been vaccinated with two doses of inactivated vaccine in January to February 2021, were included in the study. Blood samples were drawn twice, 1 month and 6 months after the second dose vaccine (CoronaVac:Sinovac Life Science Co, Ltd, Beijing, China). The antibody levels were determined by the chemiluminescence microparticle immunoassay method using kits for quantitative detection of immunoglobulin class G antibodies to severe acute respiratory syndrome coronavirus 2.

RESULTS

The mean antibody levels of 129 volunteers were 1232.5 (min: 103 to max: 7151) AU/mL in the first month and 403.5 (min: 23 to max: 4963) AU/mL in the sixth month. According to the survey results, 91 (71%) volunteers had not been diagnosed with coronavirus disease 19 before vaccination. The antibody levels 1 month and 6 months after the second dose of vaccination were significantly higher in those who had been diagnosed with coronavirus disease 19 before vaccination than in those who had not. It was found that age, gender, fast food, or healthy nutrition had no effect on antibody levels.

CONCLUSION

Vaccines are very important both to protect against coronavirus disease 19 and to experience only a mild form of the disease. Immunoglobulin class G levels formed after vaccination may be affected by many factors and may decrease over time.

Vaccine effectiveness against the B.1.617.2 in the intensive care unit

Severe acute respiratory syndrome-coronavirus 2 and its variants are still a concern for the World. The effectiveness of the BioNTech and Sinovac vaccines against the B.1.617.2 variant, particularly in the intensive care unit, has been unclear. This study aimed to investigate the vaccine effectiveness of BioNTech and Sinovac vaccines in reducing severe disease, intubation, and mortality rates in B.1.617.2 infected patients followed in the intensive care unit. The data of 208 unvaccinated and 234 vaccinated B.1.617.2 variants were retrospectively reviewed. Severe disease status, complaints, the percent oxygen saturation in the blood at the first admission, and other clinical information during follow-up were recorded. With the BioNTech and Sinovac vaccines being the most common in the region, mortality rate, severe disease, and intubation were more frequent in the unvaccinated group. As for survival rates, 58.5 (137) of the vaccinated and 35.1 % (73) of the unvaccinated survived. In the vaccinated group, 64.3 % (27) of vaccinated with 3 Sinovac, 80 % (16) of 2 Sinovac and 1 BioNTech, and 71.7 % of 2 BioNTech survived. Vaccination with 2 doses of BioNTech and 3 doses of Sinovac reduces mortality. Furthermore, 2 doses of Sinovac and 1 dose of BioNTech are more protective.

Different Safety Pattern of an Inactivated SARS-CoV-2 Vaccine (CoronaVac®) According to Age Group in a Pediatric Population from 3 to 17 Years Old, in an Open-Label Study in Chile

During the COVID-19 pandemic, the importance of vaccinating children against SARS-CoV-2 was rapidly established. This study describes the safety of CoronaVac® in children and adolescents between 3- and 17-years-old in a multicenter study in Chile with two vaccine doses in a 4-week interval. For all participants, immediate adverse events (AEs), serious AEs (SAEs), and AEs of special interest (AESIs) were registered throughout the study. In the safety subgroup, AEs were recorded 28 days after each dose. COVID-19 surveillance was performed throughout the study. A total of 1139 individuals received the first and 1102 the second dose of CoronaVac®; 835 were in the safety subgroup. The first dose showed the highest number of AEs: up to 22.2% of participants reported any local and 17.1% systemic AE. AEs were more frequent in adolescents after the first dose, were transient, and mainly mild. Pain at the inoculation site was the most frequent AE for all ages. Fever was the most frequent systemic AE for 3-5 years old and headache in 6-17 years old. No SAEs or AESIs related to vaccination occurred. Most of the COVID-19 cases were mild and managed as outpatients. CoronaVac® was safe and well tolerated in children and adolescents, with different safety patterns according to age.

Course and clinical severity of the SARS-CoV-2 Omicron variant infection in Tianjin, China

There is limited information describing the course and severity of illness in subjects infected by the severe acute respiratory syndrome coronavirus 2 Omicron variant, especially in children. In this population-based cohort study, subjects with Omicron variant infection during the outbreak between January 8 and February 12, 2022 in Tianjin, China were included (n = 429). The main outcomes were the distribution of asymptomatic, mild, moderate, and severe patients, and clinical courses including the interval from positive polymerase chain reaction (PCR) test to the onset, aggravation or relief of symptoms, and the interval of reversing positive PCR-test into negative, and length of hospital stay. Of the 429 subjects (113 [26.3%] children; 239 [55.7%] female; median age, 36 years [interquartile range 15.0 to 55.0 years]), the proportion (95% CI) of symptomatic subjects on admission was 95.6% (93.2%, 97.2%), including 60.4% (55.7%, 64.9%) mild, 35.0% (30.6%, 39.6%) moderate, and 0.2% (0.0%, 1.3%) severe. Compared with adults, children had lower proportion of moderate Covid-19 (8.8% vs 44.3%). On discharge, 45.9% (41.3%, 50.7%) and 42.2% (37.6%, 46.9%) of the subjects were diagnosed as having experienced mild and moderate Covid-19. The median (interquartile range) length of hospital stay was 14.0 (12.0, 15.0) days. The median interval of reversing positive PCR-test into negative was 12.0 (10.0, 13.0) days. Symptomatic and moderate Covid-19 in Omicron infections was common in adults and children, recovery from Omicron infections took around 2 weeks of time. The severe acute respiratory syndrome coronavirus 2 Omicron infection in this study was not as mild as previously suggested.