Scientists recently studied the association between vaccination status, infection variant, and risk for Long COVID. Their results suggest that people who were vaccinated before becoming infected with the Omicron variant of COVID-19 were less likely to develop Long COVID than other groups.*

The study

A group of researchers in Switzerland recently studied the associations between Long COVID and the COVID-19 variants Delta, Omicron, and original SARS-CoV-2 among vaccinated and unvaccinated people.

They collected data from 1,350 individuals who were diagnosed with COVID-19 between August 2020 and February 2022. Participants’ vaccination statuses were recorded, and their initial infection symptoms were categorized as mild, moderate, or severe. 

Participants were then grouped by which variant caused the infection. Those infected from July 7, 2021, to December 31, 2021, were considered Delta patients, and any infections from January 1, 2022, forward were Omicron. All data collected from the Zurich SARS-CoV-2 cohort were considered original SARS-CoV-2. 

Using patients’ self-reported data via online questionnaires, the researchers also collected information regarding overall health, current symptoms, sociodemographic information, and a Long COVID symptom screening assessment.

The results

After analyzing the data, researchers concluded that both vaccination status and infection variant may help predict Long COVID. The study found Long COVID among:

• 25% of unvaccinated patients with SARS-CoV-2 
• 17% of unvaccinated Delta patients
• 15% of vaccinated Delta patients
• 13% of unvaccinated Omicron patients
• 11% of vaccinated Omicron patients

People vaccinated before becoming infected with the Omicron variant were at the lowest risk of developing Long COVID when compared to the other groups. The severity of the initial infection, the timing of vaccination, and the number of vaccine doses were not statistically significant.

Moving forward

Even mild Long COVID symptoms can significantly impact a person’s daily life. Knowing which factors might increase people’s risk of developing Long COVID can help guide future vaccine recommendations and public health policy.

*Paharia, P. T. (2022, October 3). Vaccinated individuals infected with Omicron are less likely to experience long COVID symptoms. News-Medical.net. Retrieved October 10, 2022, from https://www.news-medical.net/news/20221002/Vaccinated-individuals-infected-with-Omicron-less-likely-to-experience-Long COVID-symptoms.aspx