Immunogenicity and safety of an inactivated SARS-CoV-2 vaccine (Sinopharm BBIBP-CorV) coadministered with quadrivalent split-virion inactivated influenza vaccine and 23-valent pneumococcal polysaccharide vaccine in China: A multicentre, non-inferiority, open-label, randomised, controlled, phase 4 trial

Immunogenicity and adverse effects of pneumococcal vaccines co-administered with influenza or SARS-CoV-2 vaccines in adults: A systematic review and Meta-analysis

BACKGROUND

This systematic review and meta-analysis aimed to investigate the immunogenicity and adverse effects (AEs) of co-administration of pneumococcal vaccines with influenza or SARS-CoV-2 vaccines.

METHODS

Following PRISMA 2020 guidelines, we searched MEDLINE, EMBASE, Web of Science, Scopus, and Google for studies published from January 1, 1950, to October 20, 2024. Randomized controlled trials (RCTs) and non-randomized studies were included. Pooled geometric mean titer (GMT) ratios per serotype and risk ratios (RR) for AEs were calculated in the meta-analyses.

RESULTS

Of 752 search hits, 17 studies were included, consisting of 14 RCTs and three non-randomized studies. One study investigated PCV20 and SARS-CoV-2 vaccine co-administration and found it safe and immunogenic. Six studies examined PPV23 and influenza vaccine co-administration, showing lower immunogenicity for some serotypes but non-inferior to single administration. A meta-analysis of studies on PCV and influenza vaccines showed significantly reduced pooled GMT ratios for several serotypes, with serotype 1 (pooled GMT ratio = 0.74, 95 % CI: [0.63, 0.87]) and 6 A (pooled GMT ratio = 0.78, 95 % CI: [0.71, 0.85]) having the lowest ratios. For AEs, PCV co-administration resulted in a 15 % increase in risk for myalgia/arthralgia (RR: 1.15, 95 % CI: 1.04-1.27) and a 34 % increase for headache (RR: 1.34, 95 % CI: 1.14-1.57). Eight studies were rated as having a moderate or severe risk of bias.

CONCLUSIONS

In adults, co-administration of pneumococcal vaccines with influenza or SARS-CoV-2 vaccines is non-inferior to single-administration; however, it can increase mild-moderate systemic AEs. Data is scarce, and further studies are needed on immunocompromised adults.

Transformative approaches in SARS-CoV-2 management: Vaccines, therapeutics and future direction

The global healthcare and economic challenges caused by the pandemic of COVID-19 reinforced the urgent demand for quick and effective therapeutic and preventative interventions. While vaccines served as the frontline of defense, antivirals emerged as adjunctive countermeasures, especially for people who developed infection, were immunocompromised, or were reluctant to be vaccinated. Beyond the serious complications of SARS-CoV-2 infection, the threats of long-COVID and the potential for zoonotic spillover continue to be significant health concerns that cannot be overlooked. Moreover, the incessant viral evolution, clinical safety issues, waning immune responses, and the emergence of drug-resistant variants pinpoint towards more severe viral threats in the future and call for broad-spectrum innovative therapies as a pre-pandemic preparedness measure. The present review provides a comprehensive up-to-date overview of the strategies utilized in the development of classical and next-generation vaccines against SARS-CoV-2, the clinical and experimental data obtained from clinical trials, while addressing safety risks that may arise. Besides vaccines, the review also covers recent breakthroughs in anti-SARS-CoV-2 drug discovery, emphasizing druggable viral and host targets, virus- and host-targeting antivirals, and highlighting mechanistically representative molecules that are either approved or are under clinical investigation. In conclusion, the integration of both vaccines and antiviral therapies, along with swift innovative strategies to address viral evolution and drug resistance is crucial to strengthen our preparedness against future viral outbreaks.

Immunogenicity, safety, and reactogenicity of concomitant administration of the novavax vaccine against Omicron XBB.1.5 (NVX-CoV2601) and a 20-valent pneumococcal conjugate vaccine in adults aged ≥60 years: A randomised, double-blind, placebo-controlled, non-inferiority trial

OBJECTIVES

There is conflicting evidence as to whether the combined administration of two vaccines can lead to poorer immunogenicity and reactogenicity. The co-administration of the Omicron-adapted COVID-19 vaccine from Novavax (NVX-CoV2601) and a 20-valent pneumococcal conjugate vaccine (PCV20) has not been previously investigated.

METHODS

In this randomised, double-blind, placebo-controlled, non-inferiority trial, immunocompetent participants aged ≥60 years were randomised in a 1:1:1:1 ratio to four groups: NVX-CoV2601 plus PCV20 (combination group); NVX-CoV2601 plus placebo (NVX-only group); PCV20 plus placebo (PCV20-only group); or placebo plus placebo (placebo group). The primary outcome was Omicron-specific anti-spike protein IgG ELISA units at day 28 in the combination group compared with the NVX-only group. Non-inferiority was established if the lower limit of the two-sided 95% CI of the geometric mean titre ratio was above the non-inferiority margin of 0.67. Secondary outcomes included anti-pneumococcal capsular polysaccharide (PCP) IgG ELISA units. Solicited local and systemic adverse events were collected for 7 days after vaccination. This study was registered with ClinicalTrials.gov, number NCT05767606, and the EU Clinical Trials Register, EudraCT number 2022-004118-12.

RESULTS

All 256 randomised participants completed the study. The baseline characteristics were similar in the four groups. Overall, the median age was 64 (IQR 61 to 69) and 105 (41%) of 256 were male. At day 28, the geometric mean anti-spike protein IgG ELISA units were 534 U/mL (95% CI 432-660) in the combination group and 556 U/mL (95% CI 460-672) in the NVX-only group, resulting in a geometric mean titre ratio of 0.96 (95% CI 0.73-1.27), thereby meeting the criteria for non-inferiority. Anti-PCP IgG ELISA units at day 28 were 507 U/mL (95% CI 416-619) in the combination group and 592 U/mL (95% CI 485-723) in the PCV20-only group. Local and systemic reactogenicity was similar in the three active treatment groups. No safety concerns or serious adverse events were observed.

CONCLUSIONS

Immunogenicity following co-administration of NVX-CoV2601 with PCV20 was non-inferior to administration of NVX-CoV2601 alone. Given the similar safety and reactogenicity profile, our findings may help to overcome concerns about concomitant vaccination and pave the way for combination vaccines.

FUNDING

Novavax.

The Impact of Vaccination on COVID-19, Influenza, and Respiratory Syncytial Virus-Related Outcomes: A Narrative Review

Vaccination represents a core preventive strategy for public health, with interrelated and multifaceted effects across health and socioeconomic domains. Beyond immediate disease prevention, immunization positively influences downstream health outcomes by mitigating complications of preexisting comorbidities and promoting healthy aging. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza virus, and respiratory syncytial virus (RSV) are common respiratory viruses responsible for broad societal cost and substantial morbidity and mortality, particularly among at-risk individuals, including older adults and people with frailty or certain comorbid conditions. In this narrative review, we summarize the overall impact of vaccination for these 3 viruses, focusing on mRNA vaccines, each of which exhibits unique patterns of infection, risk, and transmission dynamics, but collectively represent a target for preventive strategies. Vaccines for COVID-19 (caused by SARS-CoV-2) and influenza are effective against the most severe outcomes, such as hospitalization and death; these vaccines represent the most potent and cost-effective interventions for the protection of population and individual health against COVID-19 and influenza, particularly for older adults and those with comorbid conditions. Based on promising results of efficacy for the prevention of RSV-associated lower respiratory tract disease, the first RSV vaccines were approved in 2023. Immunization strategies should account for various factors leading to poor uptake, including vaccine hesitancy, socioeconomic barriers to access, cultural beliefs, and lack of knowledge of vaccines and disease states. Coadministration of vaccines and combination vaccines, such as multicomponent mRNA vaccines, offer potential advantages in logistics and delivery, thus improving uptake and reducing barriers to adoption of new vaccines. The success of the mRNA vaccine platform was powerfully demonstrated during the COVID-19 pandemic; these and other new approaches show promise as a means to overcome existing challenges in vaccine development and to sustain protection against viral changes over time.A graphical abstract and video abstract is available with this article.

Safety, reactogenicity, and immunogenicity of Ad26.COV2.S co-administered with a quadrivalent standard-dose or high-dose seasonal influenza vaccine: a non-inferiority randomised controlled trial

Background

Vaccine co-administration can increase vaccination coverage. We assessed the safety, reactogenicity, and immunogenicity of concomitant administration of Ad26.COV2.S COVID-19 vaccine with seasonal influenza vaccines.

Methods

This non-inferiority, Phase 3, randomised, double-blind study enrolled 859 healthy adults and was conducted between 02 November 2021 and 28 November 2022. Participants aged ≥18-64 years were randomised to receive a seasonal quadrivalent standard dose (SD) influenza vaccine (Afluria Quadrivalent, Seqirus) concomitantly with Ad26.COV2.S (Coad_SD) or placebo (0.9% NaCl; Control_SD) on Day 1 and placebo or Ad26.COV2.S on Day 29. Participants aged ≥65-years were randomised to the Coad_SD or Control_SD groups, or to Coad_HD or Control_HD groups that received a seasonal quadrivalent HD (high-dose) influenza vaccine (Fluzone High-Dose Quadrivalent, Sanofi Pasteur Inc) in the same schedules. The primary outcomes were haemagglutinin inhibition titres against the four influenza vaccine strains at Day 29, and SARS-CoV-2 Spike-specific antibodies at Day 29 in the Coad_SD group and Day 57 in the Control-SD group, with a non-inferiority margin (Control-SD group/Coad_SD group) of 1.5. Reactogenicity and safety were assessed in all participants (NCT05091307).

Findings

Non-inferiority criteria for concomitant administration in the SD groups were met for SARS-CoV-2 Spike-specific antibodies (ratio 1.11, 95% CI 0.97-1.26) and haemagglutinin inhibition titres for all influenza strains (A/H3N2 1.23, 95% CI 1.05-1.45; B/Victoria 0.99, 95% CI 0.84-1.19; B/Yamagata, 1.03, 95% CI 0.88-1.21) except A/H1N1 (1.28, 95% CI 1.09-1.53) for which the upper limit of the 95% CI was >1.5. Concomitant administration of Ad26.COV2.S and SD influenza vaccine induced robust immune responses in terms of SARS-CoV-2 Spike-specific antibodies and haemagglutinin inhibition to all four influenza strains. Seroconversion and seroprotection rates against all influenza vaccine strains were comparable in the Coad and Control groups. Anti-Spike antibodies 28 days after receiving Ad26.COV2.S were similar whether administered with influenza vaccine or alone. Antibody responses persisted at least 6 months post-vaccination in all groups. The reactogenicity and safety profile following co-administration was consistent with the known safety profiles of the study vaccines. No safety concerns were identified. Coadministration was immunogenic and well tolerated in adults aged ≥65 years who received HD influenza vaccine.

Interpretation

Co-administration of seasonal influenza vaccine with Ad26.COV2.S was immunogenic with an acceptable safety profile, supporting co-administration of these vaccines.

Funding

Janssen Vaccines & Prevention BV and Biomedical Advanced Research and Development Authority.

No immunological interference or concerns about safety when seasonal quadrivalent influenza vaccine is co-administered with a COVID-19 mRNA-1273 booster vaccine in adults: A randomized trial

The objective of the study was to assess the safety and immunogenicity of mRNA-1273 COVID-19 booster vaccination when co-administered with an egg-based standard dose seasonal quadrivalent influenza vaccine (QIV). This was a phase 3, randomized, open-label study. Eligible adults aged ≥ 18 years were randomly assigned (1:1) to receive mRNA-1273 (50 µg) booster vaccination and QIV 2 weeks apart (Seq group) or concomitantly (Coad group). Primary objectives were non-inferiority of haemagglutinin inhibition (HI) and anti-Spike protein antibody responses in the Coad compared to Seq group. 497/498 participants were randomized and vaccinated in the Seq/Coad groups, respectively. The adjusted geometric mean titer/concentration ratios (95% confidence intervals) (Seq/Coad) for HI antibodies were 1.02 (0.89-1.18) for A/H1N1, 0.93 (0.82-1.05) for A/H3N2, 1.00 (0.89-1.14] for B/Victoria, and 1.04 (0.93-1.17) for B/Yamagata; and 0.98 (0.84-1.13) for anti-Spike antibodies, thus meeting the protocol-specified non-inferiority criteria. The most frequently reported adverse events in both groups were pain at the injection site and myalgia. The 2 groups were similar in terms of the overall frequency, intensity, and duration of adverse events. In conclusion, co-administration of mRNA-1273 booster vaccine with QIV in adults was immunologically non-inferior to sequential administration. Safety and reactogenicity profiles were similar in both groups (clinicaltrials.gov NCT05047770).

Immunogenicity and safety of concomitant administration of recombinant COVID-19 vaccine and quadrivalent inactivated influenza vaccine in Chinese adults: An open-label, randomized, controlled trial

The immunogenicity and safety of the concomitant administration of recombinant COVID-19 vaccine and quadrivalent inactivated influenza vaccine (Split Virion) (QIIV) in Chinese adults are unclear. In this open-label, randomized controlled trial, participants aged ≥ 18 years were recruited. Eligible healthy adults were randomly assigned (1:1) to receive QIIV at the same time as the first dose of COVID-19 vaccine (simultaneous-group) or 14 days after the second dose of COVID-19 vaccine (non-simultaneous-group). The primary outcome was to compare the difference in immunogenicity of QIIV (H1N1, H3N2, Yamagata, and Victoria) between the two groups. A total of 299 participants were enrolled, 149 in the simultaneous-group and 150 in the non-simultaneous-group. There were no significant differences in geometric mean titer (GMT) [H1N1: 386.4 (95%CI: 299.2-499.0) vs. 497.4 (95%CI: 377.5-655.3); H3N2: 66.9 (95%CI: 56.1-79.8) vs. 81.4 (95%CI: 67.9-97.5); Yamagata: 95.6 (95%CI: 79.0-115.8) vs. 74.3 (95%CI: 58.6-94.0); and Victoria: 48.5 (95%CI: 37.6-62.6) vs. 65.8 (95%CI: 49.0-88.4)] and seroconversion rate (H1N1: 87.5% vs. 90.1%; H3N2: 58.1% vs. 62.0%; Yamagata: 75.0% vs. 64.5%; and Victoria: 55.1% vs. 62.8%) of QIIV antibodies between the simultaneous and non-simultaneous groups. For the seroprotection rate of QIIV antibodies, a higher seroprotection rate of Yamagata antibody was observed only in the simultaneous-group than in the non-simultaneous-group [86.0% vs. 76.0%, p = .040]. In addition, no significant difference in adverse events was observed between the two groups (14.2% vs. 23.5%, p = .053). In conclusion, no immune interference or safety concerns were found for concomitant administration of COVID-19 vaccine with QIIV in adults aged ≥ 18 years.

Unraveling the role of the nucleocapsid protein in SARS-CoV-2 pathogenesis: From viral life cycle to vaccine development

BACKGROUND

The nucleocapsid protein (N protein) is the most abundant protein in SARS-CoV-2. Viral RNA and this protein are bound by electrostatic forces, forming cytoplasmic helical structures known as nucleocapsids. Subsequently, these nucleocapsids interact with the membrane (M) protein, facilitating virus budding into early secretory compartments.

SCOPE OF REVIEW

Exploring the role of the N protein in the SARS-CoV-2 life cycle, pathogenesis, post-sequelae consequences, and interaction with host immunity has enhanced our understanding of its function and potential strategies for preventing SARS-CoV-2 infection.

MAJOR CONCLUSION

This review provides an overview of the N protein's involvement in SARS-CoV-2 infectivity, highlighting its crucial role in the virus-host protein interaction and immune system modulation, which in turn influences viral spread.

GENERAL SIGNIFICANCE

Understanding these aspects identifies the N protein as a promising target for developing effective antiviral treatments and vaccines against SARS-CoV-2.

Immunogenicity and safety of different combinations involving a third booster dose of SARS-CoV-2 inactivated vaccine, inactivated quadrivalent influenza vaccine, and 23-valent pneumococcal polysaccharide vaccine in adults aged ≥60 years: a phase 4, randomized, open-label study

Background

Concomitant administration of COVID-19, influenza, and pneumococcal vaccines could reduce the burden on healthcare systems. However, the immunogenicity and safety of various combinations of a third booster dose of SARS-CoV-2 inactivated vaccine (CoronaVac), inactivated quadrivalent influenza vaccine (IIV4), and 23-valent pneumococcal polysaccharide vaccine (PPV23), particularly in different age groups, is still unknown.

Methods

A phase 4, randomized, open-label, controlled trial was conducted in Beijing, China. 636 healthy adults were divided into two age groups (18-59 and ≥60 years) and randomized equally into three groups: CoronaVac and IIV4 followed by PPV23; CoronaVac and PPV23 followed by IIV4; or CoronaVac followed by IIV4 and PPV23, with a 28-day interval between vaccinations. Immunogenicity was evaluated by measuring antibody titers, and safety was monitored. ClinicalTrials.gov Identifier: NCT05298800.

Results

Co-administration of a third dose of CoronaVac, IIV4, and PPV23 in any combination was safe. Among adults aged 18-59, co-administration with PPV23 maintained non-inferiority of antibody levels for CoronaVac and IIV4, despite a slight reduction in antibody responses. This reduction was not observed in participants ≥60 years. Furthermore, co-administration of IIV4 and PPV23 affected seroconversion rates for both vaccines.

Conclusions

Co-administration of the third dose of SARS-CoV-2 inactivated vaccine with the influenza vaccine, followed by PPV23, may be optimal for adults aged 18-59. In adults ≥60, all vaccine combinations were immunogenic, suggesting a flexible vaccination approach. Since antibody measurements were taken 28 days post-vaccination, ongoing surveillance is essential to assess the longevity of the immune responses.

Central nervous system manifestations following vaccination against COVID-19

Coronavirus disease 2019 (COVID-19) vaccination has become the most effective countermeasure in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. However, vaccination is associated with side effects. This narrative review focuses on central nervous system (CNS) manifestations following COVID-19 vaccination and provides a summary of the potential underlying mechanisms and methods of diagnosis and management of the vaccination-related CNS manifestations. Headache, myalgia, optic neuritis, seizure, multiple sclerosis, acute disseminated encephalomyelitis and encephalitis, delirium, acute transverse myelitis, and stroke have been reported after COVID-19 vaccination. Constant headache and myalgia are common manifestations that may necessitate further clinical investigation for stroke. To limit consequences, it is imperative to follow standard treatment protocols for each neurological disorder following COVID-19 vaccination. Immunosuppressive medication can be helpful in the treatment of seizures following vaccination since the immune response is involved in their etiology. Clinicians should be aware of the manifestations after COVID-19 vaccination to respond promptly and effectively. Clinical guidelines for the management of CNS manifestations following COVID-19 vaccination are in high demand and would be useful in each new SARS-CoV-2 variant pandemic.

Immunogenicity and protective efficacy of a co-formulated two-in-one inactivated whole virus particle COVID-19/influenza vaccine

Due to the synchronous circulation of seasonal influenza viruses and severe acute respiratory coronavirus 2 (SARS-CoV-2) which causes coronavirus disease 2019 (COVID-19), there is need for routine vaccination for both COVID-19 and influenza to reduce disease severity. Here, we prepared individual WPVs composed of formalin-inactivated SARS-CoV-2 WK 521 (Ancestral strain; Co WPV) or influenza virus [A/California/07/2009 (X-179A) (H1N1) pdm; Flu WPV] to produce a two-in-one Co/Flu WPV. Serum analysis from vaccinated mice revealed that a single dose of Co/Flu WPV induced antigen-specific neutralizing antibodies against both viruses, similar to those induced by either type of WPV alone. Following infection with either virus, mice vaccinated with Co/Flu WPV showed no weight loss, reduced pneumonia and viral titers in the lung, and lower gene expression of proinflammatory cytokines, as observed with individual WPV-vaccinated. Furthermore, a pentavalent vaccine (Co/qFlu WPV) comprising of Co WPV and quadrivalent influenza vaccine (qFlu WPV) was immunogenic and protected animals from severe COVID-19. These results suggest that a single dose of the two-in-one WPV provides efficient protection against SARS-CoV-2 and influenza virus infections with no evidence of vaccine interference in mice. We propose that concomitant vaccination with the two-in-one WPV can be useful for controlling both diseases.

Bacterial Vaccinations in Patients with Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a frequent, often progressive, chronic disease of the lungs. Patients with COPD often have impaired immunity; therefore, they are prone to chest infections, such as pneumonia or bronchitis. Acute exacerbations of COPD are major events that accelerate disease progression, contributing to its symptoms' burden, morbidity, and mortality. Both pneumonia and acute exacerbations in COPD are caused by bacteria against which there are effective vaccinations. Although the number of randomised controlled studies on bacterial vaccinations in COPD is limited, national and international guidelines endorse specific vaccinations in patients with COPD. This review will summarise the different types of vaccinations that prevent pneumonia and COPD exacerbations. We also discuss the results of early phase studies. We will mainly focus on Streptococcus pneumoniae, as this bacterium was predominantly investigated in COPD. However, we also review studies investigating vaccinations against Haemophilus influenzae, Moraxella catarrhalis, and Bordetella pertussis.

A Narrative Overview of Coronavirus Infection: Clinical Signs and Symptoms, Viral Entry and Replication, Treatment Modalities, and Management

The global pandemic known as coronavirus disease (COVID-19) is causing morbidity and mortality on a daily basis. The severe acute respiratory syndrome coronavirus-2 (SARS-CoV- -2) virus has been around since December 2019 and has infected a high number of patients due to its idiopathic pathophysiology and rapid transmission. COVID-19 is now deemed a newly identified "syndrome" condition since it causes a variety of unpleasant symptoms and systemic side effects following the pandemic. Simultaneously, it always becomes potentially hazardous when new variants develop during evolution. Its random viral etiology prevents accurate and suitable therapy. Despite the fact that multiple preclinical and research studies have been conducted to combat this lethal virus, and various therapeutic targets have been identified, the precise course of therapy remains uncertain. However, just a few drugs have shown efficacy in treating this viral infection in its early stages. Currently, several medicines and vaccinations have been licensed following clinical trial research, and many countries are competing to find the most potent and effective immunizations against this highly transmissible illness. For this narrative review, we used PubMed, Google Scholar, and Scopus to obtain epidemiological data, pre-clinical and clinical trial outcomes, and recent therapeutic alternatives for treating COVID-19 viral infection. In this study, we discussed the disease's origin, etiology, transmission, current advances in clinical diagnostic technologies, different new therapeutic targets, pathophysiology, and future therapy options for this devastating virus. Finally, this review delves further into the hype surrounding the SARS-CoV-2 illness, as well as present and potential COVID-19 therapies.

Independent Protection and Influence of the Spike-Specific Antibody Response of SARS-CoV-2 Nucleocapsid Protein (N) in Whole-Virion Vaccines

Of all of the components in SARS-CoV-2 inactivated vaccines, nucleocapsid protein (N) is the most abundant and highly conserved protein. However, the function of N in these vaccines, especially its influence on the targeted spike protein's response, remains unknown. In this study, the immunization of mice with the N protein alone was shown to reduce the viral load, alleviating pulmonary pathological lesions after challenge with the SARS-CoV-2 virus. In addition, co-immunization and pre-immunization with N were found to induce higher S-specific antibody titers rather than compromise them. Remarkably, the same trend was also observed when N was administered as the booster dose after whole inactivated virus vaccination. N-specific IFN-γ-secreting T cell response was detected in all groups and exhibited a certain relationship with S-specific IgG antibody improvements. Together, these data indicate that N has an independent role in vaccine-induced protection and improves the S-specific antibody response to inactivated vaccines, revealing that an interplay mechanism may exist in the immune responses to complex virus components.

Phase 4 clinical trials in the era of the Coronavirus Disease (COVID-19) pandemic and their importance to optimize the COVID-19 vaccination

Since the appearance of SARS-CoV-2, the scientific community has worked relentlessly to gather enough information about the illness caused by this virus infection. Such great effort has resulted in increased scientific publication, including phase 4 clinical trials addressing the applicability of COVID-19 vaccines. In those trials that investigated the properties of the vaccine among participants with morbidities, mainly immunocompromised individuals, the safety was recommended, but in the presence of immunogenicity, such protection was considered of short and medium terms. It was also observed that a physically active lifestyle might increase the immunogenicity of the COVID-19 vaccination in patients with autoimmune rheumatic diseases and in immunocompromised patients. The coadministration of different types of vaccine such as the combination of the recombinant adenovirus type 5 (AD5)-vectored Convidecia as heterologous reinforcement vs. CoronaVac with homologous reinforcement in adults previously vaccinated with CoronaVac, as well as the coadministration of inactivated COVID-19 vaccine followed by the administration of the tetravalent influenza vaccine (Fragmented, Inactivated) and the pneumococcal vaccine 23 presented satisfactory immunogenicity. However, the heterologous reinforcement had better immunogenicity when compared to the homologous reinforcement. Simultaneous COVID-19 vaccination and vaccines against seasonal influenza did not raise safety issues, producing acceptable levels of adverse reactions and preserving the antibody responses against SARS-CoV-2. In the lot-to-lot consistency evaluation, CoronaVac was seen to induce an immune response considered relatively high, and the lots presented a similar profile of stability and immunogenicity, thus enabling their large-scale distribution. In brief, this article addressed, mainly, the importance of evaluating the immunological response in the COVID-19 vaccination in patients with specific health conditions (e.g., immunocompromised individuals) aiming at enabling adjustments to the vaccine calendar in national vaccination programs.

SARS-CoV-2 versus Influenza A Virus: Characteristics and Co-Treatments

For three years, the novel coronavirus disease 2019 (COVID-19) pandemic, caused by infection of the SARS-CoV-2 virus, has completely changed our lifestyles and prepared us to live with this novel pneumonia for years to come. Given that pre-existing flu is caused by the influenza A virus, we have begun unprecedently co-coping with two different respiratory diseases at the same time. Hence, we draw a comparison between SARS-CoV-2 and influenza A virus based on the general characteristics, especially the main variants’ history and the distribution of the two viruses. SARS-CoV-2 appeared to mutate more frequently and independently of locations than the influenza A virus. Furthermore, we reviewed present clinical trials on combined management against COVID-19 and influenza in order to explore better solutions against both at the same time.

From Co-Administration to Co-Formulation: The Race for New Vaccines against COVID-19 and Other Respiratory Viruses

Combined (concomitant or synchronous) vaccination is crucial to increasing the compliance rate during mass campaigns by reducing the time to deployment (i [...].