By: Tiffany Whitfield

51情报站 virologist, Emilia Oleszak, associate professor of biological sciences, has been studying coronaviruses for more than 15 years. Now that the country has entered into its second year of fighting COVID-19, scientists are learning more about this virus and the lasting side effects of those who have recovered.

Q. What are the lasting side effects of COVID-19?

A. Although most individuals infected with SARS-CoV-2 develop only a flu-like syndrome, about 20% of them would require hospitalization and some will die from the infection. Unfortunately, after recovery, many patients (possibly up to 50%) are reporting chronic, diverse ongoing symptoms such as fatigue, shortness of breath, cough, chest pain, joint and muscle pain, as well as loss of smell and taste and impaired memory. Long-term side effects of COVID-19 may lead to myocarditis and heart failure, breathing problems due to scarring of lung tissue, stroke, and seizures

Q. Why is the virus causing some people/demographics to have more long-lasting effects?

A. The immune response as well as the pattern of disease induced by any virus is specific for groups of individuals. Individual immune response can be as unique as a fingerprint. In the case of polio virus, 95% infected people were asymptomatic, 4-5% developed mild disease, and around 1% developed motor neuron disease (paralysis). So, in this sense SARS-CoV-2 is not unique. The same divergent symptoms have been observed in populations infected with chickenpox virus, RSV, influenza and many other viruses.

In elderly patients, the immune system is often impaired in aging individuals resulting in fewer and sometimes impaired T-cells which mount the antiviral response, making elimination of virus by the immune system more difficult. Men are also at higher risk for developing an abnormally high immune response to the virus.

Older individuals can also have disproportionate damage to their type 2 pneumocytes (cells present in the wall of alveoli) compared to younger patients. Damage to alveoli results in loss of air exchange and leakage of fluid into lungs. This could explain that young SARS-CoV-2 infected patients may be asymptomatic. It is not known whether damage to the pneumocytes is due to replication of the virus or collateral damage induced by the immune response.

Older survivors (and some younger, too) may be prone to developing more serious inflammatory diseases, which could accelerate diabetes, COPD, hypertension, arthritis and autoimmune disease already present in higher proportion of older population

Q. How long could these side effects of COVID-19 last?

A. The literature on the adverse side effects of this ongoing "experiment in nature" is scant. Longitudinal studies need to be carried out to understand these chronic symptoms using large group of patients. Members of National Institute of Aging (NIH) have suggested the creation of a Nationwide Registry of patients 60 years and older who survive COVID-19 infection. This public health strategy would allow to identify subjects at high risk of developing age-related disease for early intervention.

Q: Will some people have to seek long term care to overcome these side effects?

A. A lot of people who survived COVID-19 and returned home still require occupational therapy. A growing number of health systems around the country are opening dedicated clinics for patients with post-COVID-19 symptoms. These facilities are staffed with a team of physicians, practitioners and mental health professionals are trained in recovery strategies and rehabilitation for post-COVID-19 survivors.