Long COVID is prevalent among older adults and women, but the risk of developing persistent COVID-19 symptoms can be lowered through vaccination, according to a new study published Thursday in JAMA Network Open.
The World Health Organization defines long COVID as generally occurring three months after the onset of COVID-19, with symptoms lasting for at least two months. A Centers for Disease Control and Prevention investigation using electronic health record data found that one in four people aged 65 or more years experienced a new onset of a disease associated with COVID-19 at least 30 days from onset of symptoms.
Most aspects of long COVID remain poorly understood, however, according to the authors of the JAMA study. A particular area of interest is the role of prior vaccination and long COVID risk.
In this study of more than 16,000 individuals, researchers used data from eight waves of the COVD States Project, a large-scale intervention survey conducted for an academic consortium every six weeks between Feb. 5, 2021, and July 6, 2022. They found that 15% of participants with a prior positive COVID-19 test reported symptoms lasting longer than two months.
Researchers found that older adults and females had the greatest risk of long COVID. Among the most commonly reported symptoms were fatigue (52.2%), loss of smell (43.7%), brain fog (40.4%) and shortness of breath (39.7%).
Completion of the primary vaccine series — two doses of two-dose vaccine series — prior to infection was associated with diminished risk for long COVID, whereas partial vaccination — a single dose from a two-dose series — did not significantly reduce risk.
According to the CDC’s COVID Data Tracker, 80% of the US population has received at least one COVID-19 dose, and 68.2% have completed the primary vaccination series. In addition, 49.1% of the population has received the first booster dose, and 40.6% has received a second booster dose.
Among older adults, those numbers are higher, with 93% of adults aged 65 or more years completing the primary vaccine series, 71.6% receiving their first booster dose, and 48% receiving a second booster dose.
The authors said that further investigation is warranted in identifying differences in the prevalence of long COVID by race and ethnicity, educational and income levels, urban versus rural settings, and variant type at the time of infection, “because it may help to inform efforts to understand the mechanisms underlying the development of this syndrome.”
The study was conducted by researchers from Massachusetts General Hospital, Harvard Medical School and Harvard University, Northeastern University, Rutgers University and the University of Pennsylvania.
