Obesity and Metabolic Dysregulation in Children Provide Protective Influenza Vaccine Responses

The most effective intervention for influenza prevention is vaccination. However, there are conflicting data on influenza vaccine antibody responses in obese children. Cardio-metabolic parameters such as waist circumference, cholesterol, insulin sensitivity, and blood pressure are used to subdivide individuals with overweight or obese BMI into ‘healthy’ (MHOO) or ‘unhealthy’ (MUOO) metabolic phenotypes. The ever-evolving metabolic phenotypes in children may be elucidated by using vaccine stimulation to characterize cytokine responses. We conducted a prospective cohort study evaluating influenza vaccine responses in children. Participants were identified as either normal-weight children (NWC) or overweight/obese using BMI. Children with obesity were then characterized using metabolic health metrics. These metrics consisted of changes in serum cytokine and chemokine concentrations measured via multiplex assay at baseline and repeated at one month following vaccination. Changes in NWC, MHOO and MUOO were compared using Chi-square/Fisher’s exact test for antibody responses and Kruskal–Wallis test for cytokines. Differences in influenza antibody responses in normal, MHOO and MUOO children were statistically indistinguishable. IL-13 was decreased in MUOO children compared to NWC and MHOO children (p = 0.04). IL-10 approached a statistically significant decrease in MUOO compared to MHOO and NWC (p = 0.07). Influenza vaccination does not provoke different responses in NCW, MHOO, or MUOO children, suggesting that obesity, whether metabolically healthy or unhealthy, does not alter the efficacy of vaccination. IL-13 levels in MUO children were significantly different from levels in normal and MHOO children, indicating that the metabolically unhealthy phenotypes may be associated with an altered inflammatory response. A larger sample size with greater numbers of metabolically unhealthy children may lend more insight into the relationship of chronic inflammation secondary to obesity with vaccine immunity.

Development of specific immunity in laboratory animals after co-immunization against seasonal influenza and COVID-19

Introduction. In clinical practice, the differential diagnosis of COVID-19 can be challenging during the flu season, entailing serious consequences such as delays in appropriate control measures against the SARS-CoV-2 pandemic. Another problem is posed by co-infection of SARS-CoV-2 and influenza virus (IV), which significantly contributes to the severity of the COVID-19 disease. This study was aimed to explore the cross-impact of co-administration of Russian influenza and COVID-19 vaccines on development of specific immunity in laboratory animals.Materials and methods. The study was conducted on BALB/c mice. The animals were inoculated intramuscularly with the vaccine for COVID-19 prevention (CoviVac) and the vaccine for influenza prevention (Flu-M). The sera from the immunized animals were examined separately. Three IV strains were used in the hemagglutination inhibition assay. Antibodies (Abs) against SARS-CoV-2 were detected by an enzyme-linked immunosorbent assay (ELISA). The neutralization test was performed to detect virus neutralizing antibodies against SARS-CoV-2 and IV.Results. Relatively high titers of specific Abs were found in the groups of animals inoculated with one vaccine and with two vaccines concurrently. In the groups of animals inoculated with CoviVac and with two vaccines concurrently, both in the ELISA test and in the neutralization test, the average titers of specific Abs against SARSCoV- 2 did not demonstrate any statistical difference. The group of animals inoculated concurrently with two vaccines demonstrated statistically higher titers of Abs against IV after the second immunization compared to the group of animals inoculated with Flu-M.Discussion. The study has shown that post-vaccination immunity both to IV and to SARS-CoV-2 develops after co-vaccination with two vaccines. The observed enhanced post-vaccination immune response to IV in the coimmunized laboratory animals needs further research.Conclusion. The performed studies suggest the possibility of co-administration of two vaccines to prevent influenza and COVID-19.

Seasonal Influenza Prevention and Control Progress in Latin America and the Caribbean in the Context of the Global Influenza Strategy and the COVID-19 Pandemic

Each year in Latin America and the Caribbean, seasonal influenza is associated with an estimated 36,500 respiratory deaths and 400,000 hospitalizations. Since the 2009 influenza A(H1N1) pandemic, the Region has made significant advances in the prevention and control of seasonal influenza, including improved surveillance systems, burden estimates, and vaccination of at-risk groups. The Global Influenza Strategy 2019–2030 provides a framework to strengthen these advances. Against the backdrop of this new framework, the University of Colorado convened in October 2020 its Immunization Advisory Group of Experts to review and discuss current surveillance, prevention, and control strategies for seasonal influenza in Latin America and the Caribbean, also in the context of the COVID-19 pandemic. This review identified five areas for action and made recommendations specific to each area. The Region should continue its efforts to strengthen surveillance and impact evaluations. Existing data on disease burden, seasonality patterns, and vaccination effectiveness should be used to inform decision-making at the country level as well as advocacy efforts for programmatic resources. Regional and country strategic plans should be prepared and include specific targets for 2030. Existing investments in influenza prevention and control, including for immunization programs, should be optimized. Finally, regional partnerships, such as the regional networks for syndromic surveillance and vaccine effectiveness evaluation (SARInet and REVELAC-i), should continue to play a critical role in continuous learning and standardization by sharing experiences and best practices among countries.

Topical Issues of Influenza Vaccine Prevention

Influenza vaccination coverage has been expanding in recent years in Russian Federation. The topicality of influenza vaccination becomes more significant now at the beginning of seasonal increase in its prevalence, moreover, along with active immunization against coronavirus infection. Vaccination is crucial part in combined program of influenza prevention and control. Nowadays, the priority in influenza prevention is quadrivalent vaccines that can ensure the development of the most stable immunity. Russia has all the necessary resources to create and effectively implement modern influenza vaccines that meet international standards. Despite the remaining difficulties in combating influenza, preventive vaccination is by far the most effective method of protection that has proven its safety and efficacy.

Comparative Analysis of Approaches to Assess the Quality of Inactivated Influenza Vaccines: Regulatory Requirements in the Russian Federation and European Union

The experience with the influenza pandemic caused by strain A (H1N1) 2009 and the existing gaps in standardizing and evaluating the quality and effectiveness of vaccines for influenza prevention have led the European Union (EU) to recognize the need to review / update the current guidelines on requirements for the development, quality, and preclinical and clinical research. In February 2018 Guideline on influenza vaccines -quality module (EMA/CHMP/BWP/310834/2012 Rev.l) came Into effect In the EU countries. The formation of the Eurasian Economic Union (EAEU) and the creation of a single market for pharmaceutical products entails the need to amend the current and the formation of new legislation, as well as changes in the rules and regulations regarding the pharmaceutical circulation processes in the Russian Federation: development, quality assurance in preclinical and clinical trials, monitoring the safety of medicines for medical use, in this regard, it seems appropriate to develop scientific and technical guidelines that are harmonized with international standards and approaches in the pharmaceutical field. The aim of the review was to conduct a comparative analysis of approaches to assessing the quality of vaccines for prevention influenza based regulatory requirements in the Russian Federation and European Union. Conclusion. In this article discusses the features of the requirements for the development and quality control of inactivated influenza vaccines in the Russian Federation and the EU. The article provides a comparative analysis of the requirements of the State Pharmacopoeia of the Russian Federation and the European Pharmacopoeia for quality indicators, which should be included in the regulatory documentation when registering the vaccine. The main changes in the EMA document «Guidelines for influenza vaccines - Quality module» consist of new approaches to standardizing vaccines for influenza prevention, in particular, determining the specific activity of inactivated influenza vaccines using adequate alternative methods and studying biological, immunological and physicochemical characteristics HA antigen using a wide range method. The results of the analysis of approaches to assessing the quality of vaccines for influenza prevention can be useful in developing harmonized with international norms and approaches scientific and technical guidelines in the pharmaceutical field.

New Points of Departure for More Global Influenza Vaccine Use

Each year, influenza causes a significant acute respiratory disease burden. In addition, influenza pandemics periodically occur. Annual vaccination is the best tool for influenza prevention, but its effectiveness can vary from year to year. The narrow specificity of conventional vaccines and the drug resistance of currently circulating viruses reduce the effectiveness of prophylaxis and treatment and require the development of new broad-spectrum preparations. Furthermore, the challenge of creating a highly effective universal influenza vaccine takes on renewed intensity in the face of the COVID-19 pandemic.