Clinical Characteristics and Risk Factors for Severe Disease of Coronavirus Disease 2019 in a Low Case Fatality Rate Region in Korea

Adult Immunization Policy in Korea

Although adult immunization is different from children's, vaccine preventable diseases (VPDs) for adults are significant in that they are more severe and cause more deaths than VPDs for children. Additionally, the emergence of new vaccines and an increase in the elderly population are increasing demands for policy support for adult vaccination. Accordingly, in this paper, I will look at the characteristics of adult immunization, policies that have been implemented in Korea, and considerations.

Antibiotic Prescription in Patients With Coronavirus Disease 2019: Analysis of National Health Insurance System Data in the Republic of Korea

BACKGROUND

Although coronavirus disease 2019 (COVID-19) is a viral infection, antibiotics are often prescribed due to concerns about accompanying bacterial infection. Therefore, we aimed to analyze the number of patients with COVID-19 who received antibiotic prescriptions, as well as factors that influenced antibiotics prescription, using the National Health Insurance System database.

METHODS

We retrospectively reviewed claims data for adults aged ≥ 19 years hospitalized for COVID-19 from December 1, 2019 to December 31, 2020. According to the National Institutes of Health guidelines for severity classification, we calculated the proportion of patients who received antibiotics and the number of days of therapy per 1,000 patient-days. Factors contributing to antibiotic use were determined using linear regression analysis. In addition, antibiotic prescription data for patients with influenza hospitalized from 2018 to 2021 were compared with those for patients with COVID-19, using an integrated database from Korea Disease Control and Prevention Agency-COVID19-National Health Insurance Service cohort (K-COV-N cohort), which was partially adjusted and obtained from October 2020 to December 2021.

RESULTS

Of the 55,228 patients, 46.6% were males, 55.9% were aged ≥ 50 years, and most patients (88.7%) had no underlying diseases. The majority (84.3%; n = 46,576) were classified as having mild-to-moderate illness, with 11.2% (n = 6,168) and 4.5% (n = 2,484) having severe and critical illness, respectively. Antibiotics were prescribed to 27.3% (n = 15,081) of the total study population, and to 73.8%, 87.6%, and 17.9% of patients with severe, critical, and mild-to-moderate illness, respectively. Fluoroquinolones were the most commonly prescribed antibiotics (15.1%; n = 8,348), followed by third-generation cephalosporins (10.4%; n = 5,729) and beta-lactam/beta-lactamase inhibitors (6.9%; n = 3,822). Older age, COVID-19 severity, and underlying medical conditions contributed significantly to antibiotic prescription requirement. The antibiotic use rate was higher in the influenza group (57.1%) than in the total COVID-19 patient group (21.2%), and higher in severe-to-critical COVID-19 cases (66.6%) than in influenza cases.

CONCLUSION

Although most patients with COVID-19 had mild to moderate illness, more than a quarter were prescribed antibiotics. Judicious use of antibiotics is necessary for patients with COVID-19, considering the severity of disease and risk of bacterial co-infection.

Comparison of antibody responses before and after booster doses with the Pfizer-BioNTech or Oxford-AstraZeneca vaccines in healthcare workers in Thailand

The severe acute respiratory syndrome 2 (SARS-CoV-2) has spread rapidly worldwide, not only causing significant morbidity and mortality but also dramatically increasing health care spending. To manage this in Thailand, healthcare workers first received two doses of the CoronaVac vaccine followed by a booster vaccine with either BNT162b2 vaccine (Pfizer-BioNTech; PZ) or ChAdOx1 nCoV-19 vaccine (Oxford-AstraZeneca; AZ). Given that the difference in anti-SARS-CoV-2 levels following vaccination may vary depending on the vaccine and on demographic characteristics, we measured the antibody response after the second CoronaVac dose and after the booster with either the PZ or AZ vaccine. Our results in 473 healthcare workers show that the variation in antibody response to the full CoronaVac dose depends on demographic characteristics such as age, gender, body mass index, and underlying disease. After receiving a booster dose, anti-SARS-CoV-2 levels were significantly higher in participants who received the PZ vaccine than in people who received the AZ vaccine. Overall, however, receiving a booster dose of either the PZ or AZ vaccine promoted strong antibody responses, even in the old and those with obesity or diabetes mellitus. In conclusion, our results support the use of a booster vaccination program after full vaccination with the CoronaVac vaccine. This approach effectively enhances immunity against SARS-CoV-2, especially in clinically vulnerable groups and healthcare workers.

COVID-19 Outbreak in Daegu City, Korea and Response to COVID-19: How Have We Dealt and What Are the Lessons?

The first coronavirus disease 2019 (COVID-19) outbreak in Daegu city was overcome by efforts, including; 1) prompt isolation and quarantine action by local government with cooperative help from expert groups and the central government, 2) high-intensity social distancing and active cooperation of citizens, 3) admission of asymptomatic and mild patients in 'residential treatment centers', and 4) use of a telephone scoring system for the allocation of patients, with a mortality rate of 2.5%. A continuous suppression policy with test, tracing, and treatment (3 Ts) was implemented as an active response to the initial outbreaks in Korea. With the introduction of vaccines and therapeutic agents, the COVID-19 crisis had improved. Recently, the omicron variant was responsible for most domestic outbreaks, albeit with a low mortality rate (0.1%). Since the omicron outbreak, a damage mitigation policy has been implemented, focusing on protecting vulnerable groups. In the future, preparation including below are needed; 1) improving the national public health emergency response system, 2) strengthening the crisis response capacity of local governments, 3) cooperation between public healthcare and private healthcare, and 4) establishing a resilient medical response system.

How We Have Treated Severe to Critically Ill Patients With Coronavirus Disease 2019 in Korea

Since 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide, and the coronavirus disease 2019 (COVID-19) pandemic currently continues. In response to this unprecedented pandemic, several researchers and medical staff have struggled to find appropriate treatments for COVID-19. Patients with mild symptoms can recuperate with symptomatic care, however establishing treatment for severe to critically ill patients who can have a high mortality has been essential. Accordingly, the guidelines for COVID-19 treatment have evolved through numerous trials and errors and have been relatively well established to date. In the Republic of Korea, several evidence-based guidelines for COVID-19 treatment were released and revised, reflecting various research and regional medical conditions. To date, approximately 3 years after the beginning of the COVID-19 pandemic, we are reflecting on the changes in the guidelines thus far and have summarized the treatment experience of severe to critically ill patients with COVID-19. The Korean guidelines for COVID-19 treatment have been updated continuously as the National Institutes of Health (NIH) guidelines have changed. Dexamethasone is currently used as the backbone for the treatment of severe to critically ill patients with COVID-19, and remdesivir, baricitinib, and tocilizumab can be added depending on a patient's situation. In addition, venous thromboembolism prophylaxis is one of the important adjunctive therapies for patients with severe COVID-19. In the clinical field, treatment of severely ill patients with COVID-19 based on guidelines is widely practiced by medical staff and established currently.

COVID-19 Vaccination in Korea: Past, Present, and the Way Forward

Since its first emergence in late 2019, severe acute respiratory syndrome coronavirus-2 has claimed more than 6.5 million lives worldwide and continues to infect hundreds of thousands of people daily. To combat this once-in-a-century disaster, several vaccines have been developed at unprecedented speeds. Novel vaccine platforms (messenger ribonucleic acid vaccines and adenoviral vector vaccines) have played a major role in the current pandemic. In Korea, six vaccines, including a domestically developed recombinant vaccine, have been approved. As in other countries, vaccines have been proven to be safe and highly effective in Korea. However, rare serious adverse events and breakthrough infections have undermined public trust in the vaccines, even while the benefits of vaccination far outweigh the risks. The rise of the omicron variant and the subsequent increase in excess mortality demonstrated that while vaccines are a key component of the pandemic response, it alone can fail without non-pharmaceutical interventions like masking and social distancing. The pandemic of coronavirus disease has revealed both the strengths and weaknesses of our healthcare system and pandemic preparedness. When the next pandemic arrives, improved risk communication and vaccine development should be prioritized. To enable timely vaccine development, it is essential to make strategic and sufficient investments in vaccine research and development.

Fluvoxamine Treatment of Patients with Symptomatic COVID-19 in a Community Treatment Center: A Preliminary Result of Randomized Controlled Trial

Background

This study aimed to evaluate whether fluvoxamine reduces clinical deterioration in adult patients with mild to moderate coronavirus disease 2019 (COVID-19), and to identify risk factors for clinical deterioration in patients admitted to a community treatment center (CTC).

Materials and Methods

A randomized, placebo-controlled trial was conducted in a CTC, in Seoul, Korea from January 15, 2021, to February 19, 2021. Symptomatic adult patients with positive results of severe acute respiratory syndrome coronavirus 2 real time-polymerase chain reaction within 3 days of randomization were assigned at random to receive 100 mg of fluvoxamine or placebo twice daily for 10 days. The primary outcome was clinical deterioration defined by any of the following criteria: oxygen requirement to keep oxygen saturation over 94.0%, aggravation of pneumonia with dyspnea, or World Health Organization clinical progression scale 4 or greater.

Results

Of 52 randomized participants [median (interquartile range) age, 53.5 (43.3 - 60.0) years; 31 (60.0%) men], 44 (85.0%) completed the trial. Clinical deterioration occurred in 2 of 26 patients in each group (P >0.99). There were no serious adverse events in either group. Clinical deterioration occurred in 15 (6.0%) of 271 patients admitted to the CTC, and all of them were transferred to a hospital. In multivariate analysis, age between 55 and 64, fever and pneumonia at admission were independent risk factors for clinical deterioration.

Conclusion

In this study of adult patients with symptomatic COVID-19 who were admitted to the CTC, there was no significant differences in clinical deterioration between patients treated with fluvoxamine and placebo (ClinicalTrials.gov Identifier: NCT04711863).