1. Post COVID-19 Risks for COPD Patients
The progression of the COVID-19 pandemic has revealed that some patients continue to experience multi-systemic clinical features and complications beyond the initial period of acute infection and illness. COPD patients have been identified as a high-risk group for severe post-COVID-19 syndrome 
. Persistent symptoms and/or delayed or long-term complications of SARS-CoV-2 infection beyond four weeks are currently referred to as post-acute or long COVID-19 
. Recent reviews have further categorized it into two groups: (1) symptoms and clinical features present from 4–12 weeks beyond acute COVID-19 are termed subacute or ongoing symptomatic COVID-19; (2) symptoms and clinical features that persist or present beyond 12 weeks of the onset of acute COVID-19 and are not attributable to alternative diagnoses are termed long COVID-19 
2. Post COVID-19 and COPD Exacerbations
The definition of an exacerbation is the worsening of COPD symptoms leading to the need for additional pharmacological treatment 
. Among the poor outcomes for COPD patients with frequent exacerbations are reduced lung function and high mortality rate 
. The common causes of COPD exacerbations include viral 
and bacterial 
. During the current COVID-19 pandemic, SARS-CoV-2 virus infection is one of the likely causes of acute COPD exacerbations. While seasonal causes of acute COPD exacerbations include coronaviruses, it remains controversial whether COVID-19 and long COVID-19 in a COPD patient should be considered an exacerbation or not. A COPD patient with COVID-19 and/or long COVID-19 presenting with worsening cough and dyspnea would meet the requirements. However, the pathophysiology of a typical COPD exacerbation is very different from COVID-19-associated pneumonia and long COVID19, based on imaging and post-mortem features 
. COVID-19 and long COVID-19 in a COPD patient likely involve different pathological processes.
3. What Are the Treatments for COPD Patients with COVID-19 and Long COVID-19?
Considering underlying COPD is crucial when treating COVID-19 and long COVID-19 in COPD patients, as their features differ from typical of COPD exacerbations. Even after diagnosing COVID-19 and long COVID-19 in COPD patients, a concomitant exacerbation requiring treatment cannot be ruled out. Antibiotics and bronchodilators are often prescribed for COPD exacerbations, but whether and how these therapies should be administered to COPD patients during the pandemic remain unanswered questions.
Not all COPD exacerbations need to be treated with antibiotics 
, which should be reserved for exacerbations that require hospitalization or ventilatory support based on current guidelines 
. Occasional concomitant bacterial infections have been reported in COVID-19, as shown in a recent meta-analysis where 8% of COVID-19 patients had bacterial or fungal co-infection 
. Increasing severity of COVID-19 is associated with increased risk of co-infection, as demonstrated in a cohort study that reported that 50% of COVID-19 non-survivors experienced secondary infections and 31% had ventilator-associated pneumonia 
. Considering the difficulty in distinguishing SARS-CoV-2 infections from bacterial pneumonia and the high risk of bacterial infections in COPD patients, local/national pneumonia guidelines recommend treating hospitalized COPD patients with COVID-19 and long COVID-19 with broad-spectrum antibiotics. This follows WHO treatment guidelines for severe COVID-19 and long COVID-19 
. Performing microbiological analysis, such as sputum culture, upon hospital admission for exacerbated COPD patients and stopping antibiotics in the absence of co-infection is reasonable 
. However, clinical data on bacterial co-infections in COVID-19 and COPD patients are lacking, and more research is needed to determine the role of antibiotics in treating COVID-19 patients with COPD exacerbations.
Hospitalized COPD patients experiencing exacerbations are often prescribed nebulized bronchodilators, although pressurized metered-dose inhalers (pMDI) used with a spacer are an alternative mode of inhalation. pMDIs have been shown to be non-inferior to nebulizers in exacerbation management 
. Some long-acting dual bronchodilators have rapid onset of action, are more effective, and last longer, making them a preferred option 
. High doses of nebulized short-acting bronchodilators are often administered for COPD exacerbations, and there is no maximum specified dose. It is advisable to double the maximum maintenance dose of long-acting bronchodilators to make it equivalent to the high doses of short-acting bronchodilators for COPD exacerbations. Bronchodilators administered via pMDI and spacer are recommended over nebulizer treatment in symptomatic exacerbated COPD patients with COVID-19 and long COVID-19, since the safety of nebulizers is still controversial.
4. Rehabilitation & Recovery of COPD Patients with Long COVID-19
Considerable morbidity is experienced by patients with severe COVID-19 during hospitalization, including lethargy, dyspnea, diffuse myalgias, and cognitive dysfunction, which may persist even after recovery from acute illness 
. After hospital discharge, 50% of patients with severe COVID-19 experience worsened dyspnea, impaired exercise tolerance, and may benefit from pulmonary rehabilitation (PR) 
. Patients with underlying COPD may experience more pronounced post-COVID-19 complications due to underlying structural lung damage. Multiple randomized controlled trials, meta-analyses, and evidence-based reviews provide strong evidence of the benefits of PR in symptomatic COPD patients 
. PR is one of the most effective treatment strategies for improving COPD patients’ dyspnea, health status, and exercise tolerance. It may also help to reduce anxiety and depressive symptoms. However, due to social restrictions, physical separation, and concerns about SARS-CoV-2 community transmission, conventional PR cannot be easily performed during the pandemic.
The pandemic has had various impacts on COPD patients. Physical clinic and home visits have been reduced along with PR sessions. As a result, many COPD patients have stayed at home despite experiencing severe exacerbations, leading to delayed treatment and poor outcomes, which is similar to what has been observed for other diseases such as myocardial infarction 
. Adapting to new healthcare norms involves expanding telehealth and virtual clinics. Multiple randomized controlled trials have shown that telehealth for COPD patients is non-inferior to usual care in terms of exacerbations, hospital admissions, and quality of life 
. Online PR program sessions appear to be just as effective as in-person sessions 
. Establishing virtual programs is encouraged to ensure that COPD patients receive optimal care despite social distancing measures 
. In-person PR should not occur when the community prevalence of COVID-19 is high because COPD patients are vulnerable to severe complications of COVID-19 
. However, in-person PR may be considered when the community spread of COVID-19 is low. It is important to note that social exercise, especially indoors, is a high-risk activity for COVID-19 transmission 
5. Vaccination and COPD
Several vaccines against COVID-19 have been developed and have shown to be effective. A subgroup analysis of a recent phase 3 randomized trial showed that the mRNA-1273 vaccine was equally effective in preventing COVID-19 in subjects with and without risk factors for severe disease, including chronic lung disease 
. However, due to their rapid development, evidence regarding the efficacy and potential adverse effects of these vaccines for different demographic is still lacking. Therefore, further studies are needed to determine their effectiveness and safety among people with COPD and other comorbidities. Studies have investigated the correlations between influenza vaccination, susceptibility to SARS-CoV-2 infection, and outcomes of COVID-19. Influenza vaccination has been found to be independently associated with a lower risk of mortality at 60 days in COVID-19 patients (OR = 0.2; 95% CI = 0.082–0.510) 
. Another study in the UK showed reduced odds of all-cause mortality (OR = 0.76; 95% CI = 0.64–0.90) in COVID-19 patients 
. Preventing influenza with a vaccine may lower the viral load and severity of COVID-19. However, an Italian study found no association between death or hospitalization and the flu vaccine 
. Given this evidence, it is recommended that COPD patients receive vaccination against both seasonal flu and/or COVID-19 to minimize their risks of severe disease and mortality.
6. Influence of Public Health Measures on Care for COPD Patients in the Pandemic
Public health measures, such as social distancing, lockdown, and reduced face-to-face consultations during the pandemic, have had a significant impact on healthcare-seeking behavior and access to healthcare. Hospitalizations for COPD exacerbations decreased during the pandemic due to reduced infection exposure during social isolation 
. However, the impact of these public health measures on the quality of care and control of chronic conditions requires careful evaluation.
The recent surveys conducted in China and Spain provide valuable insights into the impact of the COVID-19 pandemic on COPD patients. The survey of 153 COPD patients in China showed that most continued to use their inhaled medications as before the pandemic, with only 30% experiencing worsening respiratory symptoms 
. Of those who experienced symptoms, 55.5% did not seek medical attention due to fear of contracting the virus, while 28.8% managed mild symptoms on their own. In Spain, a study of 100 patients conducted by telephone interview found that 90% of patients had medical consultations or complementary tests cancelled during lockdowns 
. However, approximately 60% had a medical visit by telephone and reported a high degree of satisfaction. Notably, 63% of patients considered their lung health status to be the same as before lockdown, and 19% even felt better. Taken together, these surveys suggest that public health interventions during the pandemic can help to control COPD and that telemedicine may be an effective way to provide medical care for COPD patients when in-person visits are not possible.
The Global Initiative for Chronic Obstructive Lung Disease (GOLD) recently introduced a tool to support remote follow-up for COPD patients 
. This tool encourages standardized evaluation and documentation, ensuring high-quality patient follow-up. Clinicians and policymakers are interested in the potential impact of applying this tool or similar ones to patient care.