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Original Articles
mRNA vaccine effectiveness against SARS-CoV-2 B.1.617.2 (Delta) and B.1.1.529 (Omicron) variant transmission from home care cases to household contacts in South Korea
Hanul Park, Young Joon Park, Sang Eun Lee, Min Jei Lee, Hyungtae Ahn
Received September 1, 2022  Accepted November 1, 2022  Published online November 28, 2022  
DOI: https://doi.org/10.24171/j.phrp.2022.0243    [Epub ahead of print]
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AbstractAbstract PDF
Objectives
Household contacts of confirmed cases of coronavirus disease 2019 (COVID-19) are exposed to a high risk of viral transmission, and secondary incidence is an important indicator of community transmission. This study analyzed the secondary attack rate and mRNA vaccine effectiveness against transmission (VET) for index cases (patients treated at home) confirmed to be infected with the Delta and Omicron variants.
Methods
The subjects of the study were 4,450 index cases and 10,382 household contacts. Logistic regression analysis was performed to compare the secondary attack rate by vaccination status, and adjusted relative risk and 95% confidence intervals were identified.
Results
The secondary attack rate of the Delta variant was 27.3%, while the secondary attack rate of the Omicron variant was 29.8%. For the Delta variant, groups with less than 90 days and more than 90 days after 2 doses of mRNA vaccination both showed a VET of 37%. For the Omicron variant, a 64% VET was found among those with less than 90 days after 2 doses of mRNA vaccination.
Conclusion
This study provides useful data on the secondary attack rate and VET of mRNA vaccines for household contacts of COVID-19 cases in South Korea.
Time-series comparison of COVID-19 case fatality rates across 21 countries with adjustment for multiple covariates
Yongmoon Kim, Bryan Inho Kim, Sangwoo Tak
Received July 25, 2022  Accepted October 18, 2022  Published online November 28, 2022  
DOI: https://doi.org/10.24171/j.phrp.2022.0212    [Epub ahead of print]
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AbstractAbstract PDF
Objectives
Although it is widely used as a measure for mortality, the case fatality rate (CFR) of coronavirus disease 2019 (COVID-19) can vary over time and fluctuate for many reasons other than viral characteristics. To compare the CFRs of different countries in equal measure, we estimated comparable CFRs after adjusting for multiple covariates and examined the main factors that contributed to variability in the CFRs among 21 countries.
Methods
For statistical analysis, time-series cross-sectional data were collected from Our World in Data, CoVariants.org, and GISAID. Biweekly CFRs of COVID-19 were estimated by pooled generalized linear squares regression models for the panel data. Covariates included the predominant virus variant, reproduction rate, vaccination, national economic status, hospital beds, diabetes prevalence, and population share of individuals older than age 65. In total, 21 countries were eligible for analysis.
Results
Adjustment for covariates reduced variation in the CFRs of COVID-19 across countries and over time. Regression results showed that the dominant spread of the Omicron variant, reproduction rate, and vaccination were associated with lower country-level CFRs, whereas age, the extreme poverty rate, and diabetes prevalence were associated with higher country-level CFRs.
Conclusion
A direct comparison of crude CFRs among countries may be fallacious, especially in a cross-sectional analysis. Our study presents an adjusted comparison of CFRs over time for a more proper comparison. In addition, our findings suggest that comparing CFRs among different countries without considering their context, such as the epidemic phase, medical capacity, surveillance strategy, and socio-demographic traits, should be avoided.
Review Article
SARS-CoV-2 in brief: from virus to prevention
Hassan Karami, Zeinab Karimi, Negin Karami
Received May 21, 2022  Accepted October 11, 2022  Published online November 28, 2022  
DOI: https://doi.org/10.24171/j.phrp.2022.0155    [Epub ahead of print]
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AbstractAbstract PDF
The recent outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a highly transmissible virus with a likely animal origin, has posed major and unprecedented challenges to millions of lives across the affected nations of the world. This outbreak first occurred in China, and despite massive regional and global attempts shortly thereafter, it spread to other countries and caused millions of deaths worldwide. This review presents key information about the characteristics of SARS-CoV-2 and its associated disease (namely, coronavirus disease 2019) and briefly discusses the origin of the virus. Herein, we also briefly summarize the strategies used against viral spread and transmission.
Original Article
Clinical outcomes of remdesivir-treated COVID-19 patients in South Korea
Mi Yu, Bryan Inho Kim, Jungyeon Kim, Jin Gwack
Osong Public Health Res Perspect. 2022;13(5):370-376.   Published online October 18, 2022
DOI: https://doi.org/10.24171/j.phrp.2022.0138
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AbstractAbstract PDF
Objectives
This study analyzed the clinical outcomes of remdesivir treatment in coronavirus disease 2019 (COVID-19) patients in South Korea.
Methods
This retrospective cohort study involved the secondary analysis of epidemiological data. Among patients diagnosed with COVID-19 from July 2, 2020 to March 23, 2021 (12 AM), 4,868 who received oxygen therapy and were released from isolation after receiving remdesivir treatment were assigned to the treatment group, and 6,068 patients who received oxygen therapy but not remdesivir were assigned to the untreated group. The study subjects included children under the age of 19. The general characteristics and severity were compared between the groups. Differences in the time to death and mortality were also compared.
Results
In the untreated group, the hazard ratio [HR] for mortality was 1.59 among patients aged ≥70 years and 2.32 in patients with severe disease in comparison to the treatment group. In a comparison of survival time among patients with severe disease aged ≥70 years, the HR for mortality before 50 days was 2.09 in the untreated group compared to the treatment group.
Conclusion
Patients with remdesivir treatment showed better clinical outcomes in this study, but these results should be interpreted with caution since this study was not a fully controlled clinical trial.
Brief Reports
Adverse events of the Pfizer-BioNTech COVID-19 vaccine in Korean children and adolescents aged 5 to 17 years
Seontae Kim, Yeseul Heo, Soon-Young Seo, Do Sang Lim, Enhi Cho, Yeon-Kyeng Lee
Osong Public Health Res Perspect. 2022;13(5):382-390.   Published online October 14, 2022
DOI: https://doi.org/10.24171/j.phrp.2022.0233
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AbstractAbstract PDF
Objectives
This study aimed to identify potential safety signals and adverse events following the primary Pfizer-BioNTech coronavirus disease 2019 (COVID-19) vaccination series among children and adolescents aged 5 to 17 years in the Republic of Korea. Methods: Adverse events reported through the COVID-19 vaccination management system (CVMS, a web-based passive vaccine safety surveillance system) and adverse events and health conditions collected from a text message-based survey were analyzed. Results: A total of 14,786 adverse events among 5 to 17-year-old children and adolescents were reported in the CVMS; 14,334 (96.9%) were non-serious and 452 (3.1%) were serious, including 125 suspected cases of acute cardiovascular injury and 101 suspected cases of anaphylaxis. The overall reporting rate was lower in 5 to 11-year-old children (64.5 per 100,000 doses) than in 12 to 17-year-old adolescents (300.5 per 100,000 doses). The text message survey identified that local and systemic adverse events after either dose were reported less frequently in 5 to 11-year-old children than in 12 to 17-year-old adolescents (p<0.001). The most commonly reported adverse events were pain at the injection site, myalgia, headache, and fatigue/tiredness. Conclusion: The overall results are consistent with the results of controlled trials; serious adverse events were extremely rare among 5 to 17-year-old children and adolescents following Pfizer-BioNTech COVID-19 vaccination. Adverse events were less frequent in children aged 5 to 11 years than in adolescents aged 12 to 17 years.
Presumed population immunity to SARS-CoV-2 in South Korea, April 2022
Eun Jung Jang, Young June Choe, Seung Ah Choe, Yoo-Yeon Kim, Ryu Kyung Kim, Jia Kim, Do Sang Lim, Ju Hee Lee, Seonju Yi, Sangwon Lee, Young-Joon Park
Osong Public Health Res Perspect. 2022;13(5):377-381.   Published online October 14, 2022
DOI: https://doi.org/10.24171/j.phrp.2022.0209
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Graphical AbstractGraphical Abstract AbstractAbstract PDF
Objectives
We estimated the overall and age-specific percentages of the Korean population with presumed immunity against severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) as of April 2022 using the national registry.
Methods
We used the national coronavirus disease 2019 (COVID-19) infection and vaccination registry from South Korea, as described to define individuals with a previous history of COVID-19 infection, vaccination, or both, as persons with presumed immunity.
Results
Of a total of 53,304,627 observed persons, 24.4% had vaccination and infection, 58.1% had vaccination and no infection, 7.6% had infection and no vaccination, and 9.9% had no immunity. The SARS-CoV-2 Omicron variant emerged at a time when the presumed population immunity ranged from 80% to 85%; however, nearly half of the children were presumed to have no immunity.
Conclusion
We report a gap in population immunity, with lower presumed protection in children than in adults. The approach presented in this work can provide valuable informed tools to assist vaccine policy-making at a national level.
Review Article
India’s efforts to achieve 1.5 billion COVID-19 vaccinations: a narrative review
Kapil Singh, Ashwani Verma, Monisha Lakshminarayan
Osong Public Health Res Perspect. 2022;13(5):316-327.   Published online October 14, 2022
DOI: https://doi.org/10.24171/j.phrp.2022.0104
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Graphical AbstractGraphical Abstract AbstractAbstract PDF
The initial case of coronavirus disease 2019 (COVID-19) in India was reported on January 30, 2020, and subsequently, the number of COVID-19-infected patients surged during the first wave of April 2020 and the second wave in the same month of 2021. The government of India imposed a strict nationwide lockdown in April 2020 and extended it until May 2020. The second wave of COVID-19 in India overwhelmed the country’s health facilities and exhausted its medical and paramedical workforce. This narrative review was conducted with the aim of summarizing the evidence drawn from policy documents of governmental and non-governmental organizations, as well as capturing India's COVID-19 vaccination efforts. The findings from this review cover the Indian government's vaccination initiatives, which ranged from steps taken to combat vaccine hesitancy to vaccination roadmaps, deployment plans, the use of digital health technology, vaccination monitoring, adverse effects, and innovative strategies such as Har Ghar Dastak and Jan Bhagidari Andolan (people’s participation). These efforts collectively culminated in the successful administration of more than 1.8 billion doses of COVID-19 vaccines in India. This review also provides insights into other countries’ responses to COVID-19 and guidance for future pandemics.
Original Articles
The role of risk perception, risk communication, and demographic factors in COVID-19 preventive behaviors: an online survey in Iran
Mansour Rezaei, Nader Rajabi Gilan, Ali Almasi, Mehdi Khezeli, Fatemeh Jamshidi Nazar, Zahra Jorjoran Shushtari, Yahya Salimi, Farid Najafi, Neda Sarabi, Shahram Saeidi, Saeid Saeidi
Osong Public Health Res Perspect. 2022;13(4):282-289.   Published online August 31, 2022
DOI: https://doi.org/10.24171/j.phrp.2021.0345
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AbstractAbstract PDF
Objectives
This study investigated preventive behaviors toward coronavirus disease 2019 (COVID-19) and related factors in a Kurdish Iranian sample.
Methods
This online survey was conducted among the population aged 18 and above in Kermanshah Province, in western Iran, in April 2020. Samples were invited and recruited through social media. Data were collected using a questionnaire consisting of 4 sections (questions on demographic variables, risk perception, risk communication, and COVID-19 preventive behaviors) and analyzed using Stata ver. 8.
Results
The Pearson correlation test showed that risk communication was significantly correlated with COVID-19 preventive behaviors (r=0.320, p<0.01). In the final model, where the explanatory power increased with the entry of the risk communication variable, the variables explained a total of 14% of variance in COVID-19 preventive behaviors. Sex (β=−0.482), risk perception (β=0.047), and risk communication (β=0.662) were significant determinants.
Conclusion
Risk communication and risk perception related to COVID-19, as well as being a woman, were determinants of COVID-19 preventive behaviors.
Characteristics of COVID-19 outbreaks and risk factors for transmission at an army training center in South Korea from June to August 2021
U Jin Cho, Seongjin Wang, Seonju Yi, Yeon Hwa Choi, Eun-Young Kim, Jin A Kim, Sanghwan Bae, Jungyeon Yu, Jangkyu Choi, Young-Joon Park
Osong Public Health Res Perspect. 2022;13(4):263-272.   Published online July 27, 2022
DOI: https://doi.org/10.24171/j.phrp.2022.0149
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AbstractAbstract PDF
Objectives
It is crucial to establish the characteristics of coronavirus disease 2019 (COVID-19) outbreaks at army training centers to develop preventive measures. Therefore, this study aimed to determine the COVID-19 transmission patterns and risk factors in a sequence of outbreaks at an army training center from June to August 2021.
Methods
This study included 1,324 trainees at an army training center where outbreaks occurred from June to August 2021. The outbreak was qualitatively analyzed according to the period, attack rate, demographic characteristics, vaccination history, and living areas. An aerodynamic experiment was performed to evaluate aerosol transmission in living areas.
Results
Three outbreaks occurred at the army training center from June to August 2021. The first, second, and third outbreaks lasted for 32, 17, and 24 days, and the attack rates were 12.8%, 18.1%, and 8.9%, respectively. Confirmed cases were distributed in all age groups. Recruits and the unvaccinated were at higher risk for COVID-19. The aerodynamic experiment verified the possibility of aerosol transmission within the same living area.
Conclusion
COVID-19 transmission at army training centers should be minimized through quarantine and post-admission testing during the latency period as part of integrated measures that include facility ventilation, vaccination, indoor mask-wearing, and social distancing.
Clinical epidemiological applicability of real-time polymerase chain reaction for COVID-19
Geehyuk Kim, Jun-Kyu Kang, Jungho Kim, Jiyoung Lee, Jin Gwack
Osong Public Health Res Perspect. 2022;13(4):252-262.   Published online July 27, 2022
DOI: https://doi.org/10.24171/j.phrp.2022.0135
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Graphical AbstractGraphical Abstract AbstractAbstract PDF
Objectives
Real-time polymerase chain reaction is currently used as a confirmatory test for coronavirus disease 2019 (COVID-19). The test results are interpreted as positive, negative, or inconclusive, and are used only for a qualitative classification of patients. However, the test results can be quantitated using threshold count (Ct) values to determine the amount of virus present in the sample. Therefore, this study investigated the diagnostic usefulness of Ct results through various quantitative analyzes, along with an analysis of clinical and epidemiological characteristics.
Methods
Clinical and epidemiological data from 4,642 COVID-19 patients in April 2021 were analyzed, including the Ct values of the RNA-dependent RNA polymerase (RdRp), envelope (E), and nucleocapsid (N) genes. Clinical and epidemiological data (sex, age, underlying diseases, and early symptoms) were collected through a structured questionnaire. A correlation analysis was used to examine the relationships between variables.
Results
All 3 genes showed statistically significant relationships with symptoms and severity levels. The Ct values of the RdRp gene decreased as the severity of the patients increased. Moreover, statistical significance was observed for the presence of underlying diseases and dyspnea.
Conclusion
Ct values were found to be related to patients’ clinical and epidemiological characteristics. In particular, since these factors are closely related to symptoms and severity, Ct values can be used as primary data for predicting patients’ disease prognosis despite the limitations of this method. Conducting follow-up studies to validate this approach might enable using the data from this study to establish policies for preventing COVID-19 infection and spread.
Changes in the pattern and disease burden of acute respiratory viral infections before and during the COVID-19 pandemic
Chungmin Park, Donghan Lee, Bryan Inho Kim, Sujin Park, Gyehee Lee, Sangwoo Tak
Osong Public Health Res Perspect. 2022;13(3):203-211.   Published online June 30, 2022
DOI: https://doi.org/10.24171/j.phrp.2022.0144
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AbstractAbstract PDF
Objectives
We conducted a comparative analysis of the differences in the incidence of 8 acute respiratory viruses and the changes in their patterns before and during the coronavirus disease 2019 (COVID-19) pandemic. Methods: Three sentinel surveillance systems of the Korea Disease Control and Prevention Agency and data from the Health Insurance Review and Assessment Service were analyzed. The average numbers of reported cases and the related hospital admissions and outpatient data were compared between April 2018–2019 and 2020–2021. Changes in the disease burden and medical expenditures between these 2 time periods were evaluated. Results: During the COVID-19 pandemic, the number of reported cases of all acute respiratory viral infections, except for human bocavirus, decreased significantly. Data from the Health Insurance Review and Assessment Service also showed decreases in the actual amount of medical service usage and a marked reduction in medical expenditures. Conclusion: Non-pharmacological interventions in response to COVID-19 showed preventive effects on the transmission of other respiratory viruses, as well as COVID-19. Although COVID-19 had a tremendous impact on society as a whole, with high social costs, there were also positive effects, such as a reduction in the incidence of acute respiratory viral infections.
Transmission parameters of coronavirus disease 2019 in South Asian countries
Mridul Sannyal, Abul Mukid Mohammad Mukaddes
Osong Public Health Res Perspect. 2022;13(3):191-202.   Published online June 23, 2022
DOI: https://doi.org/10.24171/j.phrp.2021.0234
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Graphical AbstractGraphical Abstract AbstractAbstract PDF
Objectives
This study aimed to estimate the transmission parameters, effective reproduction number, epidemic peak, and future exposure of coronavirus disease 2019 (COVID-19) in South Asian countries. Methods: A susceptible-exposed-infected-recovered-death (SEIRD) model programmed with MATLAB was developed for this purpose. Data were collected (till June 28, 2021) from the official webpage of World Health Organization, along with the Center for Systems Science and Engineering at Johns Hopkins University. The model was simulated to measure the primary transmission parameters. The reproduction number was measured using the next-generating matrix method. Results: The primary transmission rate followed an exponential Gaussian process regression. India showed the highest transmission rate (0.037) and Bhutan the lowest (0.023). The simulated epidemic peaks matched the reported peaks, thereby validating the SEIRD model. The simulation was carried out up to December 31, 2020 using the reported data till June 9, 2020. Conclusion: The information gathered in this research will be helpful for authorities to prevent the transmission of COVID-19 in the subsequent wave or in the future.
Brief Report
Safety monitoring of COVID-19 vaccination among adolescents aged 12 to 17 years old in the Republic of Korea
Seontae Kim, Insob Hwang, Mijeong Ko, Yunhyung Kwon, Yeon-Kyeng Lee
Osong Public Health Res Perspect. 2022;13(3):230-237.   Published online June 10, 2022
DOI: https://doi.org/10.24171/j.phrp.2022.0122
  • 1,617 View
  • 92 Download
  • 1 Citations
Graphical AbstractGraphical Abstract AbstractAbstract PDF
Objectives
This study aimed to disseminate information on coronavirus disease 2019 (COVID-19) vaccine safety among adolescents aged 12 to 17 years in the Republic of Korea. Methods: Two databases were used to assess COVID-19 vaccine safety in adolescents aged 12 to 17 years who completed the primary Pfizer-BioNTech vaccination series. Adverse events reported to the web-based COVID-19 vaccination management system (CVMS) and collected in the text message-based system were analyzed. Results: From March 5, 2021 to February 13, 2022, 12,216 adverse events among 12- to 17-yearolds were reported to the CVMS, of which 97.1% were non-serious adverse events and 2.9% were serious adverse events, including 85 suspected cases of anaphylaxis, 74 suspected cases of myocarditis and/or pericarditis, and 2 deaths. From December 13, 2021 to January 26, 2022, 10,389 adolescents responded to a text message survey, and local/systemic adverse events were more common after dose 2 than after dose 1. The most commonly reported events following either vaccine dose were pain at the injection site, headache, fatigue/tiredness, and myalgia. Conclusion: The overall results are consistent with previous findings; the great majority of adverse events were non-serious, and serious adverse events were rare among adolescents aged 12 to 17 years following Pfizer-BioNTech COVID-19 vaccination.

Citations

Citations to this article as recorded by  
  • COVID-19 Vaccination in Korea: Past, Present, and the Way Forward
    Eliel Nham, Joon Young Song, Ji Yun Noh, Hee Jin Cheong, Woo Joo Kim
    Journal of Korean Medical Science.2022;[Epub]     CrossRef
Original Articles
Voluntary testing for COVID-19: perceptions and utilization among the inhabitants of Saudi Arabia
Ehab A. Abo-Ali, Ahmed Mousa, Rania Hussien, Shahad Mousa, Shayma Al-Rubaki, Mennatulla Omar, Badr Al-Haffashi, Abdullah Almilaibary
Osong Public Health Res Perspect. 2022;13(3):212-220.   Published online June 10, 2022
DOI: https://doi.org/10.24171/j.phrp.2022.0062
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AbstractAbstract PDF
Objectives
Voluntary testing (VT) plays a crucial role in the prevention and control of infectious diseases. The present study investigated the perceptions and utilization of VT services for coronavirus disease 2019 (COVID-19) among the inhabitants of Saudi Arabia. Methods: In total, 3,510 adult participants from all provinces of Saudi Arabia were recruited via a national online survey. Results: Of the 3,510 participants, 88.9% were aware of the testing services available to them and of those, more than half (59.5%) had used the VT services and 96.1% were satisfied with the services. Contact with a positive COVID-19 case was the top reason for accessing VT, while a lack of awareness about the availability of VT services was the top perceived limiting factor. A history of chronic health conditions, anxiety and/or depression, and previous symptoms suggestive of COVID-19 were found to be predictors of the utilization of VT services (odds ratio [OR] 1.55, 95% confidence interval [CI] 1.22−1.96; OR 1.48, 95% CI 1.16−1.88; and OR 3.31, 95% CI 2.77−3.95), respectively. Conclusion: The awareness of voluntary COVID-19 testing services was satisfactory among the Saudi Arabian population, but can be improved. Sociodemographic and health history predictors of the utilization of VT services were identified.
Seroprevalence of immunoglobulin G antibodies against SARS-CoV-2 in children and adolescents in Delhi, India, from January to October 2021: a repeated cross-sectional analysis
Pragya Sharma, Saurav Basu, Suruchi Mishra, Mongjam Meghachandra Singh
Osong Public Health Res Perspect. 2022;13(3):184-190.   Published online June 10, 2022
DOI: https://doi.org/10.24171/j.phrp.2022.0014
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  • 60 Download
  • 1 Citations
Graphical AbstractGraphical Abstract AbstractAbstract PDF
Objectives
The aim of this study was to assess changes in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) seroprevalence among children and adolescents in Delhi, India from January 2021 to October 2021. Methods: This was a repeated cross-sectional analysis of participants aged 5 to 17 years from 2 SARS-CoV-2 seroprevalence surveys conducted in Delhi, India during January 2021 and September to October 2021. Anti-SARS-CoV-2 IgG antibodies were detected by using the VITROS assay (90% sensitivity, 100% specificity). Results: The seroprevalence among 5- to 17-year-old school-age children and adolescents increased from 52.8% (95% confidence interval [CI], 51.3%−54.3%) in January 2021 to 81.8% (95% CI, 80.9%−82.6%) in September to October 2021. The assay-adjusted seroprevalence was 90.8% (95% CI, 89.8%−91.7%). Seropositivity positively correlated with participants’ age (p<0.001), but not sex (p=0.388). A signal to cut-off ratio ≥4.00, correlating with the presence of neutralization antibodies, was observed in 4,814 (57.9%) participants. Conclusion: The high percentage of seroconversion among children and adolescents indicates the presence of natural infection-induced immunity from past exposure to the SARS-CoV-2 virus. However, the lack of hybrid immunity and the concomitant likelihood of lower levels of neutralization antibodies than in adults due to the absence of vaccination warrants careful monitoring and surveillance of infection risk and disease severity from newer and emergent variants.

Citations

Citations to this article as recorded by  
  • Seroprevalence of SARS CoV-2 among children after the second surge (June 2021) in a rural district of South India: Findings and lessons from a population-based survey
    Carolin Elizabeth George, Leeberk Raja Inbaraj, Shon Rajukutty, Roshni Florina Joan, Sangeetha Muthuraj, Sindhulina Chandrasingh
    Frontiers in Pediatrics.2022;[Epub]     CrossRef

PHRP : Osong Public Health and Research Perspectives