Reduced Risk of Long COVID with Omicron versus Delta Variant

Last week, the Lancet published an observational study that concluded a reduced risk of developing long COVID when infected with the omicron versus the delta variant. The CDC defines long COVID, sometimes called post-COVID conditions, as “a wide range of new, returning, or ongoing health problems that people experience after first being infected with the virus that causes COVID-19.” 

Symptoms of long COVID range from general fatigue to neurological issues. One common symptom of long COVID is brain fog. Brain fog encompasses a broad range of definitions but is dominated by memory and concentration issues.  

Research by the University of Oxford found that 70% of long COVID patients reported issues with memory and concentration months after their COVID diagnosis. 

Symptoms of long COVID not only have physical manifestations but also contribute to and exacerbate mental health issues. While vaccination has alleviated the risk of developing long COVID, it has not discontinued it.  

According to a meta-analysis published in the Oxford Academic Journal of Infectious Diseases, in 2019, long-COVID occurred in approximately 43% of global COVID survivors and 49% of United States COVID survivors.  

Long COVID risk is not well studied but is thought to be based on many factors, including vaccination status, comorbidities, and severity of COVID illness. The Lancet study aimed to analyze whether the type of variant a patient is infected with could also impact risk. 

To analyze self-reported patient information, the researchers set specific date ranges for omicron and delta variant data. They identified any self-reported dates from December 20, 2021, to March 9, 2022, as omicron cases and dates from June 1, 2021, to November 27, 2021, as delta cases.  

While there is no 100% certainty that data from these date ranges are exclusive to each variant, they did note that most cases in each date range were attributed to the assigned variant.  

Despite multiple limitations, including an unequal gender distribution of participants, the investigators concluded that rates of long COVID were reduced in omicron patients compared to delta patients.  

Due to the nature of this ever-changing illness, the published article stipulates that these conclusions are based on the investigated sample size and may not necessarily be upheld for larger or later sample sizes.  

Treatment of long COVID may require a multidisciplinary care team and extended patient support. Data collection on long COVID risk factors may alter early intervention and care access for this unprecedented condition.