New study finds varying levels of improvement among long COVID patients after three years

A new study has found that a significant proportion of people who experience long COVID show improvement within three years of contracting the SARS-CoV-2 virus.

The study tracked over 1,000 patients with long COVID and discovered varying levels of improvement depending on the specific symptoms they experienced. Roughly 60% of those whose primary symptoms were related to changes in their sense of taste or smell showed significant improvement after three years.

However, a different picture emerged for patients who exhibited a multisystem presentation of long COVID. This group had symptoms that affected multiple bodily systems, including cardiac, nervous, and gastrointestinal systems, and less than 20% showed improvement over the same time frame.

The distinction between these two subtypes of long COVID raises questions about the underlying causes of this condition and its various manifestations. Experts have noted that long COVID shares similarities with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), which can arise after an infection and affects multiple bodily systems.

Researchers have been tracking thousands of adults across the United States who previously tested positive for COVID-19 as part of a National Institutes of Health-funded project.

The study used a 30-point scale called the 2024 LC Research Index (LCRI) to score patients based on their symptoms, including fatigue, brain fog, shortness of breath and heart palpitations. Patients with scores above 10 points were included in the study.

Of nearly 1,020 patients who met this requirement, scientists monitored them over time through regular in-person appointments and symptom surveys every three months.

The data showed that after two years, about 36% of participants had shown improvement, as indicated by LCRI scores of 10 or less at two consecutive visits.

The researchers behind the study took a closer look at which SARS-CoV-2 strain was associated with long COVID cases, factoring in vaccination status.

Patients infected with Omicron variants of the virus were more likely to show improvement than those infected with earlier strains, suggesting that the specific type of virus may play a role in determining outcomes.

However, some patients' recovery journeys were far from straightforward, and researchers noted that not all participants who showed initial improvement went on to make full recoveries.

Interestingly, adults under 46 appeared more likely to show improvement than older participants, with men and women improving at similar rates despite this age-related difference.

The study also found stark differences in improvement rates among patients grouped by their predominant symptoms, with those in the last three subtypes - chronic cough, brain fog, and heart palpitations - showing lower recovery rates.

The study's findings have significant implications for understanding and treating long COVID, a condition that has puzzled healthcare professionals since its emergence.

Researchers believe that long COVID may be triggering ME/CFS in some patients, suggesting that these two conditions share similar characteristics.

ME/CFS is a poorly understood disease that affects various bodily systems and can be triggered by different infections, although the underlying cause remains unclear.

The study's subtypes of long COVID point to the need for tailored treatments, which could be informed by further research into the genetic and protein mechanisms driving these conditions.