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1.
Anal Chem ; 95(22): 8541-8551, 2023 06 06.
Article in English | MEDLINE | ID: covidwho-2327203

ABSTRACT

Therapeutic monoclonal antibodies (mAbs) provide effective treatments for many diseases, including cancer, autoimmune disorders, and, lately, COVID-19. Monitoring the concentrations of mAbs is important during their production and subsequent processing. This work demonstrates a 5 min quantitation of most human immunoglobulin G (IgG) antibodies through capture of mAbs in membranes modified with ligands that bind to the fragment crystallizable (Fc) region. This enables binding and quantitation of most IgG mAbs. Layer-by-layer (LBL) adsorption of carboxylic acid-rich polyelectrolytes in glass-fiber membranes in 96-well plates allows functionalization of the membranes with Protein A or a peptide, oxidized Fc20 (oFc20), with high affinity for the Fc region of human IgG. mAb capture occurs in <1 min during the flow of solutions through modified membranes, and subsequent binding of a fluorophore-labeled secondary antibody enables quantitation of the captured mAbs using fluorescence. The intra- and inter-plate coefficients of variations (CV) are <10 and 15%, respectively, satisfying the acceptance criteria for many assays. The limit of detection (LOD) of 15 ng/mL is on the high end of commercial enzyme-linked immunosorbent assays (ELISAs) but certainly low enough for monitoring of manufacturing solutions. Importantly, the membrane-based method requires <5 minutes, whereas ELISAs typically take at least 90 min. Membranes functionalized with oFc20 show greater mAb binding and lower LODs than membranes with Protein A. Thus, the membrane-based 96-well-plate assay, which is effective in diluted fermentation broths and in mixtures with cell lysates, is suitable for near-real-time monitoring of the general class of human IgG mAbs during their production.


Subject(s)
Antibodies, Monoclonal , COVID-19 , Humans , Ligands , Immunoglobulin G , Enzyme-Linked Immunosorbent Assay/methods
2.
Vaccines (Basel) ; 10(9)2022 Sep 18.
Article in English | MEDLINE | ID: covidwho-2044024

ABSTRACT

(1) Purpose: This study aimed to analyze coronavirus disease 2019 (COVID-19) vaccine policies and their effectiveness in Italy, India, and South Africa to provide empirical experience for vaccination and COVID-19 pandemic control. (2) Methods: The study systematically summarized the COVID-19 vaccine policies in Italy, India, and South Africa through public information available on the official websites of the World Health Organization and the ministries of health in these three countries. Total vaccinations, COVID-19 vaccination rates, rates of fully vaccinated, rates of booster-vaccinated, and total confirmed cases were selected for cross-sectional comparison of COVID-19 vaccination in these three countries. Daily cases per million, daily deaths per million, and the effective reproduction rate were calculated to measure the effectiveness of COVID-19 vaccine policies implementation in each of these three countries. (3) Results: Italy, India, and South Africa differ in the start date of COVID-19 vaccination, vaccine types, vaccine appointments, and whether vaccinations are free. The COVID-19 vaccination rates in these three countries varied widely, with Italy having the highest and South Africa the lowest. COVID-19 vaccination has had a positive effect on reducing daily deaths and stabilizing the effective reproduction rate. The three countries had experienced more than one outbreak spike due to the spread of new mutated strains since the start of COVID-19 vaccination. (4) Conclusions: This study concluded that responding to the COVID-19 pandemic requires active promotion of basic and booster vaccinations to comprehensively build up the population immune barrier. Promoting equitable distribution of COVID-19 vaccine internationally and solidarity and cooperation among countries maximizes global common interests. By combining vaccination with non-pharmaceutical interventions, the pandemic can be prevented and controlled comprehensively and systematically in three aspects: detection of the source of infection, reduction of transmission routes, and protection of susceptible populations.

3.
Int J Equity Health ; 21(1): 115, 2022 08 22.
Article in English | MEDLINE | ID: covidwho-2002183

ABSTRACT

OBJECTIVE: This study aims to compare the differences in COVID-19 prevention and control policies adopted by the United Kingdom (UK) during the first wave (31 January 2020 to 6 September 2020) and the second wave (7 September 2020 to 12 April 2021), and analyze the effectiveness of the policies, so as to provide empirical experience for the prevention and control of COVID-19. Methods We systematically summarized the pandemic prevention and control policies of the UK from official websites and government documents, collated the epidemiological data from 31 January 2020 to 12 April 2021, and analyzed the effectiveness of the two waves of pandemic prevention and control policies. RESULTS: The main pandemic prevention and control policies adopted by the UK include surveillance and testing measures, border control measures, community and social measures, blockade measures, health care measures, COVID-19 vaccination measure, and relaxed pandemic prevention measures. The new cases per day curve showed only one peak in the first wave and two peaks in the second wave. The number of new cases per million in the second wave was much higher than that in the first wave, and the curve fluctuated less. The difference between mortality per million was small, and the curve fluctuated widely. CONCLUSION: During the first and second waves of COVID-19, the UK implemented three lockdowns and managed to slow the spread of the pandemic. The UK's experience in mitigating the second wave proves that advancing COVID-19 vaccination needs to be accompanied by ongoing implementation of non-pharmacological interventions to reduce the transmission rate of infection. And a stricter lockdown ensures that the containment effect is maximized during the lockdown period. In addition, these three lockdowns featured distinct mitigation strategies and the UK's response to COVID-19 is mitigation strategy that reduce new cases in the short term, but with the risk of the pandemic rebound.


Subject(s)
COVID-19 , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines , Communicable Disease Control/methods , Health Policy , Humans , SARS-CoV-2 , United Kingdom/epidemiology
4.
J Epidemiol Glob Health ; 12(2): 168-181, 2022 06.
Article in English | MEDLINE | ID: covidwho-1899424

ABSTRACT

OBJECTIVE: This study analyzes the effectiveness of COVID-19 prevention and control in China and Brazil from the perspectives of policy and meteorological conditions, and provides experience for epidemic prevention and control. METHODS: This study collects data on meteorological conditions, vaccination and mutant strains in the two countries to analyze the reasons for the differences in epidemic status between the two countries and extracts public data on COVID-19 through various official websites, summarizes the prevention and control policies implemented by the two countries, and evaluates their effectiveness. RESULTS: As of August 12, 2021, the total number of COVID-19 cases and the daily number of new COVID-19 cases in China have been growing steadily, showing remarkable results in epidemic control. The total number of confirmed cases and the daily number of new confirmed cases in Brazil have continued to increase rapidly. The total death case in Brazil has reached 560,000, far exceeding that in China, and the effect of epidemic prevention and control is not satisfactory. CONCLUSIONS: Multiple factors, such as meteorological conditions, policies and strategies, and economic conditions, can influence the spread of COVID-19, and therefore, the situation varies greatly from country to country. China and Brazil have chosen different interventions in the fight against COVID-19. The policy measures taken by China are typical containment measures and Brazil has a mitigation strategy. From the perspective of the current situation of the epidemic development in both countries, the cumulative death rate and daily new confirmed cases in Brazil are much higher than those in China, which indicates that the containment strategy is more effective than mitigation strategy in preventing and controlling COVID-19. Fighting the epidemic is a global long-lasting battle, and the two countries should learn from each other with the premise of respecting their national conditions. Countries should deepen cooperation and not let up prematurely.


Subject(s)
COVID-19 , Epidemics , Brazil/epidemiology , COVID-19/epidemiology , COVID-19/prevention & control , China/epidemiology , Humans , SARS-CoV-2
5.
Int J Equity Health ; 21(1): 57, 2022 04 29.
Article in English | MEDLINE | ID: covidwho-1875012

ABSTRACT

BACKGROUND: This study aimed to compare the prevention and control strategies adopted by the United States and India in the COVID-19 outbreak and analyze the effectiveness of their strategies, in order to provide empirical experience for the prevention and control of the epidemic. METHODS: This study extracted official data on COVID-19 from various official websites, summarized the policies in place in the United States and India, and evaluated the effectiveness of their policies. RESULTS: The United States has adopted a series of mitigation strategies to control the two waves of epidemic, including strengthening virus detection, calling on the people to wear masks and so on. As of May 30, 2021, although the daily new cases there decreased to some extent, the effect was not ideal. The US's daily new cases ranked fourth and the cumulative number of confirmed cases ranked first in the world. India has adopted containment strategies in the initial stage of the outbreak, making the epidemic relatively stable. In the later stage, India has turned to adopt mitigation strategies. In addition, many factors including the lack of medical resources and premature relaxation measures led to the rapid deterioration of the epidemic situation. As of May 30, 2021, although the daily new cases in India has a downward trend, it ranked first in the world, and the cumulative number of confirmed cases ranked second. CONCLUSION: There are differences between the epidemic prevention strategies adopted by the United States and India, especially India's containment strategies which helped it better control the epidemic in the early stage. However, the epidemic in the two countries is still severe. With the advent of virus mutants and the absence of immune barriers, it is meaningful that the two countries continue to take non-pharmacotherapy intervention measures and accelerate vaccination, according to specific national conditions adopt containment strategies that can control the epidemic more quickly when necessary, and pay attention to the risk of epidemic rebound caused by premature relaxation of epidemic prevention policies.


Subject(s)
COVID-19 , Epidemics , COVID-19/epidemiology , Disease Outbreaks , Humans , India/epidemiology , United States/epidemiology
6.
J Glob Health ; 12: 05016, 2022 May 21.
Article in English | MEDLINE | ID: covidwho-1863242

ABSTRACT

Background: COVID-19 has not been effectively controlled, seriously threatening people's health and socioeconomic development. This study aims to summarise the successful experiences and lessons in containment strategy learned from Asian Low- and Middle-Income Countries (LMICs) during the COVID-19 pandemic and analyse the effectiveness of their measures to provide lessons for LMICs in general. Methods: This is a retrospective study on the effectiveness of China, India, and Vietnam's containment strategies. The objective was to assess the effectiveness of measures taken for COVID-19 and provide lessons for wider LMICs in controlling and preventing the COVID-19 pandemic. Results: As of June 16, 2021, the Indian epidemic was in the declining part of the rebound stage, with a total of 21 521.900 cases per million and 276.740 deaths per million - both the highest among the three countries. Entering the normalised prevention and control stage, China stably remained at a total of 63. 615 cases per million and 3.211 deaths per million. Vietnam's number of new cases per million was very low in the first stage and almost stagnant except for cluster epidemics. In May 2021, the number of new cases per million started to rapidly increase, but the total of deaths per million was at the low level of 0.627. Conclusions: A high attention to epidemics at early stages, strict border control measures, and synchronization of government and population on COVID-19 prevention and control opinions and behaviours play important roles in designing containment strategies. In addition, rapid close contact tracing and large-scale nucleic testing are good options for response to cluster epidemics.


Subject(s)
COVID-19 , COVID-19/prevention & control , Developing Countries , Humans , Pandemics/prevention & control , Retrospective Studies , SARS-CoV-2
7.
Int J Equity Health ; 21(1): 9, 2022 01 20.
Article in English | MEDLINE | ID: covidwho-1643152

ABSTRACT

OBJECTIVE: To provide experience for formulating prevention and control policies, this study analyzed the effectiveness of the Coronavirus disease 2019(COVID-19) prevention and control policies, and evaluated health equity and epidemic cooperation among BRICS countries. METHODS: This study summarized the pandemic prevention and control policies in BRICS countries and evaluated the effectiveness of those policies by extracting COVID-19 related data from official websites. RESULT: As of May 4, 2021, responding to COVID-19. China adopted containment strategies. China's total confirmed cases (102,560) were stable, without a second pandemic peak, and the total deaths per million (3.37) were much lower than others. India and South Africa who adopted intermediate strategies have similar pandemic curves, total confirmed cases in India (20,664,979) surpassed South Africa (1,586,148) as the highest in five countries, but total deaths per million (163.90) lower than South Africa (919.11). Brazil and Russia adopted mitigation strategies. Total confirmed cases in Brazil (14,856,888) and Russia (4,784,497) continued to increase, and Brazil's total deaths per million (1,936.34) is higher than Russia (751.50) and other countries. CONCLUSION: This study shows BRICS countries implemented different epidemic interventions. Containment strategy is more effective than intermediate strategy and mitigation strategy in limiting the spread of COVID-19. Especially when a strict containment strategy is implemented in an early stage, but premature relaxation of restrictions may lead to rebounding. It is a good choice to combat COVID-19 by improving the inclusiveness of intervention policies, deepening BRICS epidemic cooperation, and increasing health equities.


Subject(s)
COVID-19 , Brazil , China/epidemiology , Humans , India/epidemiology , Pandemics , Policy , Russia , SARS-CoV-2 , South Africa/epidemiology
8.
Anal Chem ; 94(2): 884-891, 2022 01 18.
Article in English | MEDLINE | ID: covidwho-1608171

ABSTRACT

Quantitation of therapeutic monoclonal antibodies (mAbs) in human serum could ensure that patients have adequate levels of mAbs for effective treatment. This research describes the use of affinity, glass-fiber membranes in a 96-well-plate format for rapid (<5 min) quantitation of the therapeutic mAb trastuzumab and a mAb against the SARS-CoV-2 spike protein. Adsorption of a poly(acrylic acid)-containing film in membrane pores and activation of the -COOH groups in the film enable covalent-linking of affinity peptides or proteins to the membrane. Passage of mAb-containing serum through the affinity membrane results in mAb capture within 1 min. Subsequent rinsing, binding of a secondary antibody conjugated to a fluorophore, and a second rinse yield mAb-concentration-dependent fluorescence intensities in the wells. Calibration curves established from analyses on different days have low variability and allow determination of mAb levels in separately prepared samples with an average error <10%, although errors in single-replicate measurements may reach 40%. The assays can occur in diluted serum with physiologically relevant mAb concentrations, as well as in undiluted serum. Thus, the combination of 96-well plates containing affinity membranes, a microplate reader, and a simple vacuum manifold affords convenient mAb quantitation in <5 min.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibody Affinity , Humans , Spike Glycoprotein, Coronavirus , Trastuzumab
9.
Cities ; 116: 103273, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1252581

ABSTRACT

COVID-19 was announced by the World Health Organization as a pandemic on March 11, 2020. Not only has COVID-19 struck the economy and public health, but it also has deep influences on people's feelings. Twitter, as an active social media, is a great database where we can investigate people's sentiments during this pandemic. By conducting sentiment analysis on Tweets using advanced machine learning techniques, this study aims to investigate how public sentiments respond to the pandemic from March 2 to May 21, 2020 in New York City, Los Angeles, London, and another six global mega-cities. Results showed that across cities, negative and positive Tweet sentiment clustered around mid-March and early May, respectively. Furthermore, positive sentiments of Tweets from New York City and London were positively correlated with stricter quarantine measures, although this correlation was not significant in Los Angeles. Meanwhile, Tweet sentiments of all three cities did not exhibit a strong correlation with new cases and hospitalization. Last but not least, we provide a qualitative analysis of the reasons behind differences in correlations shown above, along with a discussion of the polarizing effect of public policies on Tweet sentiments. Thus, the results of this study imply that Tweet sentiment is more sensitive to quarantine orders than reported statistics of COVID-19, especially in populous megacities where public transportation is heavily relied upon, which calls for prompt and effective quarantine measures during contagious disease outbreaks.

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