Vaccination May Help Reduce Symptoms of Long COVID

Originally thought to be a predominantly temporary infection, a growing proportion of patients are experiencing prolonged symptoms from SARS-CoV-2 infection, or “Long COVID”.^1-3

Symptoms of Long COVID, which like COVID-19 itself, can be highly varied from patient to patient, but most commonly include fatigue, insomnia, “brain fog”, anxiety, depression, gastrointestinal symptoms, myalgia, and breathlessness.^1-3 Some symptoms extend from the acute infection while others arise later. Researchers and medical professionals do not fully understand the pathophysiological or immunological mechanism behind this unfortunate phenomenon.

Support groups and patient care clinics have been created to help patients who suffer from lasting effects of the virus and large research studies, such as the SARS-CoV-2 Recovery Cohort though NIH, aim to provide more insight into why some patients develop Long COVID and how best to manage it.¹ A recent study, not yet published in a peer-reviewed journal, may provide hope for patients via an unexpected source: vaccination.²

The study, performed with help from the LongCovidSOS campaign in the United Kingdom (UK), was initially developed to determine if COVID-19 vaccines could worsen symptoms associated with Long COVID. According to the authors, there were anecdotal reports of substantial symptom improvement following vaccination, contrasting with fear that immunization might worsen Long COVID.²

A cohort of patients admitted to a single UK hospital between April and May 2020 were recruited for a prospective observational study with follow-up at hospital discharge, 3 months (approximately June-July 2020), and 8 months (approximately December 2020 to January 2021). Over 80% of these patients reported at least 1 ongoing symptom associated with their COVID-19 infection. Within this group, 44 participants who received at least 1 dose of a COVID-19 vaccine were surveyed 1 month following vaccination (approximately January – February 2021) to evaluate Long COVID symptoms. Twenty-two unvaccinated patients in the observational cohort served as matched controls.²

At the 8-month follow-up and prior to vaccination, symptom burden was high among all patients. Those in the soon-to-be vaccinated group reporting 159 symptoms, and 91 symptoms were reported in the unvaccinated group.1 A small, but significantly greater, improvement in symptoms occurred in vaccinated patients compared to unvaccinated patients during the same period [37 of 159 (23.2%) vs. 14 of 91 (15.4%); p=0.035].²

When differences in scores across all symptoms were combined, 56.7% of individuals in the study experienced symptom improvement after 1 vaccine dose and 24.6% had no change. It is worth noting that 18.7% of patients experienced symptom deterioration which may be concerning. However, the number of patients experiencing deterioration during this period was similar between vaccinated and unvaccinated patients and it does not appear that the immunization contributed to the worsening of any symptoms.²

Generally, it appears immunization may improve Long COVID symptoms, but does not appear to exacerbate or worsen them. Almost half of vaccinated patients said the improvements were permanent. Since 72% of patients were within 30 days of vaccination, it is possible that the number of patients experiencing continued symptom improvement was underestimated and follow-up studies are required to determine the long-term impact of immunization on symptom status.²

In addition to physical symptom impact, vaccination was also associated with a significant improvement in wellbeing according to the Warwick and Edinburgh Mental Wellbeing scores (p=0.006). The study also suggests that mRNA vaccines may provide more symptom improvement than adenovirus vector vaccines, but the sample size is most likely too small to provide a conclusive comparison.²

These study results need to be confirmed in larger studies with diverse patient populations and the mechanism of the impact requires exploration. The study is too small to draw firm associations on the benefit of COVID-19 vaccination on Long COVID symptoms.² However, it does provide hope for patients who are suffering long after the acute COVID-19 infection resolves and introduces a potential novel role in therapy for these vaccinations beyond infection prevention.

REFERENCES

1. Collins FS. NIH launches new initiative to study “Long COVID”. Updated February 23, 2021. Accessed May 21, 2021. https://www.nih.gov/about-nih/who-we-are/nih-director/statements/nih-launches-new-initiative-study-long-covid
2. Arnold DT, Milne A, Samms E, et al. Are vaccines safe in patients with Long COVID? A prospective observational study. medRxiv.2021;DOI:10.1101/2021.03.11.21253225
3. Centers for Disease Control and Prevention. Post-COVID Conditions. Updated April 8, 2021. Accessed May 21, 2021. https://www.cdc.gov/coronavirus/2019-ncov/long-term-effects.html