Let's Get Vaccinated for Both Flu and COVID-19: On the World Flu Day 2021

A Gaussian Process Regression and Wavelet Transform Time Series approaches to modeling Influenza A

The global spread of Influenza A viruses is worsening economic and social challenges. Various mechanistic models have been developed to understand the virus's spread and evaluate intervention effectiveness. This study aimed to model the temporal dynamics of Influenza A using Gaussian Process Regression (GPR) and wavelet transform approaches. The study employed Continuous Wavelet Transform (CWT), Discrete Wavelet Transform (DWT) and Wavelet Power Spectrum to analyze time-series data from 2009 to 2023. The GPR model, known for its non-parametric Bayesian nature, effectively captured non-linear trends in the Influenza A data, while wavelet transforms provided insights into frequency and time-localized characteristics. The integration of GPR with DWT denoising techniques demonstrated superior performance in forecasting Influenza A cases compared to traditional models like Auto Regressive Integrated Moving Averages (ARIMA) and Exponential Smoothing (ETS) using Holt-Winter method. The study identified significant anomalies in Influenza A cases, corresponding to known pandemic events and seasonal variations. These findings highlight the effectiveness of combining wavelet transform analysis with GPR in understanding and predicting infectious disease patterns, offering valuable insights for public health planning and intervention strategies. The research recommends extending this approach to other respiratory viruses to assess its broader applicability.

Changes in the Epidemiological Features of Influenza After the COVID-19 Pandemic in China, the United States, and Australia: Updated Surveillance Data for Influenza Activity

BACKGROUND

There has been a global decrease in seasonal influenza activity since the onset of the COVID-19 pandemic.

OBJECTIVE

We aimed to describe influenza activity during the 2021/2022 season and compare it to the trends from 2012 to 2023. We also explored the influence of social and public health prevention measures during the COVID-19 pandemic on influenza activity.

METHODS

We obtained influenza data from January 1, 2012, to February 5, 2023, from publicly available platforms for China, the United States, and Australia. Mitigation measures were evaluated per the stringency index, a composite index with 9 measures. A general additive model was used to assess the stringency index and the influenza positivity rate correlation, and the deviance explained was calculated.

RESULTS

We used over 200,000 influenza surveillance data. Influenza activity remained low in the United States and Australia during the 2021/2022 season. However, it increased in the United States with a positive rate of 26.2% in the 49th week of 2022. During the 2021/2022 season, influenza activity significantly increased compared with the previous year in southern and northern China, with peak positivity rates of 28.1% and 35.1% in the second week of 2022, respectively. After the COVID-19 pandemic, the dominant influenza virus genotype in China was type B/Victoria, during the 2021/2022 season, and accounted for >98% (24,541/24,908 in the South and 20,543/20,634 in the North) of all cases. Influenza virus type B/Yamagata was not detected in all these areas after the COVID-19 pandemic. Several measures individually significantly influence local influenza activity, except for influenza type B in Australia. When combined with all the measures, the deviance explained values for influenza A and B were 87.4% (P<.05 for measures of close public transport and restrictions on international travel) and 77.6% in southern China and 83.4% (P<.05 for measures of school closing and close public transport) and 81.4% in northern China, respectively. In the United States, the association was relatively stronger, with deviance-explained values of 98.6% for influenza A and 99.1% (P<.05 for measures of restrictions on international travel and public information campaign) for influenza B. There were no discernible effects on influenza B activity in Australia between 2020 and 2022 due to the incredibly low positive rate of influenza B. Additionally, the deviance explained values were 95.8% (P<.05 for measures of restrictions on gathering size and restrictions on international travel) for influenza A and 72.7% for influenza B.

CONCLUSIONS

Influenza activity has increased gradually since 2021. Mitigation measures for COVID-19 showed correlations with influenza activity, mainly driven by the early stage of the pandemic. During late 2021 and 2022, the influence of mitigation management for COVID-19 seemingly decreased gradually, as the activity of influenza increased compared to the 2020/2021 season.

Biosafety and immunology: An interdisciplinary field for health priority

Biosafety hazards can trigger a host immune response after infection, invasion, or contact with the host. Whether infection with a microorganism results in disease or biosafety concerns depends to a large extent on the immune status of the population. Therefore, it is essential to investigate the immunological characteristics of the host and the mechanisms of biological threats and agents to protect the host more effectively. Emerging and re-emerging infectious diseases, such as the current coronavirus disease 2019 (COVID-19) pandemic, have raised concerns regarding both biosafety and immunology worldwide. Interdisciplinary studies involved in biosafety and immunology are relevant in many fields, including the development of vaccines and other immune interventions such as monoclonal antibodies and T-cells, herd immunity (or population-level barrier immunity), immunopathology, and multispecies immunity, i.e., animals and even plants. Meanwhile, advances in immunological science and technology are occurring rapidly, resulting in important research achievements that may contribute to the recognition of emerging biosafety hazards, as well as early warning, prevention, and defense systems. This review provides an overview of the interdisciplinary field of biosafety and immunology. Close collaboration and innovative application of immunology in the field of biosafety is becoming essential for human health.

Immunogenicity of an Inactivated COVID-19 Vaccine in People Living with HIV in Guangxi, China: A Prospective Cohort Study

The inactivated COVID-19 vaccine has demonstrated high efficacy in the general population through extensive clinical and real-world studies. However, its effectiveness in immunocompromised individuals, particularly those living with HIV (PLWH), remains limited. In this study, 20 PLWH and 15 HIV-seronegative individuals were recruited to evaluate the immunogenicity of an inactivated COVID-19 vaccine in PLWH through a prospective cohort study. The median age of the 20 PLWH and 15 HIV-seronegative individuals was 42 years and 31 years, respectively. Of the PLWH, nine had been on ART for over five years. The median anti-SARS-CoV-2 S-RBD IgG antibody level on d224 was higher than that on d42 (8188.7 ng/mL vs. 3200.9 ng/mL, P < 0.05). Following COVID-19 infection, the antibody level increased to 29,872.5 ng/mL on dre+90, 12.19 times higher than that on d300. Compared with HIV-seronegative individuals, the antibody level in PLWH was lower on d210 (183.3 ng/mL vs. 509.3 ng/mL, P < 0.01), while there was no difference after d224. The symptoms of COVID-19 infection in PLWH were comparable to those in HIV-seronegative individuals. In this study, the inactivated COVID-19 vaccine demonstrated good immunogenicity in PLWH. The protective benefit of booster vaccinations for PLWH cannot be ignored. Implementing a booster vaccination policy for PLWH is an effective approach to providing better protection against the COVID-19 pandemic.

Seeing the T cell Immunity of SARS-CoV-2 and SARS-CoV: Believing the Epitope-Oriented Vaccines

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at the end of 2019 stimulated vigorous research efforts in immunology and vaccinology. In addition to innate immune responses, both virus-specific humoral and cellular immune responses are of importance for viral clearance. T cell epitopes play a central role in T cell-based immune responses. Herein, we summarized the peptide/major histocompatibility complex (pMHC) structures of the SARS-CoV-2-derived T cell epitopes available in the Protein Data Bank (PDB) and proposed the challenge and opportunities for using of T cell epitopes in future vaccine development efforts. A total of 27 SARS-CoV-2 related pMHC structures and five complexes with T cell receptors were retrieved. The peptides are mainly distributed on spike (S), nucleocapsid (N), and ORF1ab proteins. Most peptides are conserved among variants of concerns (VOCs) for SARS-CoV-2, except for several mutated peptides located in the S protein. The structures of human leukocyte antigen (HLA) complexed with seven epitopes derived from SARS-CoV were also retrieved, which showed a potential cross T cell immunity with SARS-CoV-2. Structural studies of antigenic peptides from SARS-CoV-2 and SARS-CoV help to visualize the processes and the mechanisms of cross T cell immunity. T cell epitope-oriented vaccines are potential next-generation vaccines for SARS-CoV-2, which are worthy of further investigation.