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ResourcesPress Release

New study finds vaccines protect against long-COVID even after infection

Healthcare Analytics

Arcadia, in collaboration with Leavitt Partners’ COVID-19 Patient Recovery Alliance, presents novel findings on patient susceptibility to long-COVID symptoms

Vaccinations protect against long-covid
Vaccinated individuals are up to 10x less likely to report long-COVID symptoms.

Boston, Mass., Dec. 15, 2021—Arcadia (, the leading population health management and health intelligence platform, today released findings of its study published on medRxiv showing that current vaccines reduce the risk of long-COVID, even when administered up to 12 weeks after a COVID diagnosis.

Developed in collaboration with the COVID-19 Patient Recovery Alliance, these findings indicate:

  • Patients who received at least one dose of any of the three COVID vaccines (Pfizer-BioNTech, Moderna, and Johnson & Johnson) prior to their diagnosis with COVID-19 were up to ten times less likely to report two or more long-COVID symptoms compared to unvaccinated patients.
  • Unvaccinated patients who received their first COVID-19 vaccination within four weeks after SARS-CoV-2 infection were up to six times less likely to report multiple long-COVID symptoms.
  • Those who received their first dose 4-8 weeks after diagnosis were three times less likely to report multiple long-COVID symptoms compared to those who remained unvaccinated.
  • Vaccination had a protective effect even when the first dose was administered up to 12 weeks after diagnosis.

The analysis was performed using Arcadia’s aggregated, de-identified longitudinal patient data asset, which represents the health history of more than 150 million patient identities from thousands of EHR and claims data feeds all over the United States. The long-COVID analysis, based on COVID-19 infection and vaccination data over a period of 15 months (from February 2020 to May 2021), included 1.06 million persons infected with COVID-19, of which more than 240,000 had available a complete longitudinal history prior to the pandemic as well as at least one encounter with a healthcare provider at least eight weeks after their COVID-19 diagnosis.

“The persistence or emergence of symptoms after an acute infection (i.e., long-COVID) affects as many as one-quarter of all who have been infected by COVID-19, and in many, symptoms can last for months and be debilitating,” said Brett Giroir, MD, Visiting Distinguished Executive at Leavitt Partners and former Member of the White House Coronavirus Task Force. “Arcadia’s data add significantly to the compelling advantages of COVID-19 vaccination. In addition, the unexpected protective effect of vaccination even after infection suggests the presence of biological mechanisms for the development of long-COVID that were previously unsuspected and yet uninvestigated.”

“The reduced likelihood of long-COVID symptoms observed in our study provides a rationale for vaccination sooner rather than later, achieving improved patient health outcomes related to long-COVID,” said Richard Parker, MD, Chief Medical Officer at Arcadia. “From a clinical perspective, it answers a question many doctors have been asking as to whether or not to defer vaccinating infected patients until they have recovered from the acute illness. Based on the evidence, an unvaccinated person infected with COVID would benefit from immediate vaccination much like patients with rabies and Hepatitis B benefit from those vaccines.”

“This study represents an additional application of the HIPAA-compliant, NCQA- certified Arcadia Analytics platform which continuously aggregates and curates high-quality, up-to-date population health data assets, and provides actionable insights to improve healthcare quality, access, and cost-effectiveness,” said Michael Simon, Director of Data Science at Arcadia. “Our company’s mission is to support providers, health plans, and life science innovators with novel insights that can only be obtained by analyzing data on a massive scale.”

This study is a part of an ongoing research collaboration with the COVID-19 Patient Recovery Alliance, a partnership of healthcare organizations convened by Gov. Michael O. Leavitt and Nancy-Ann DeParle to coordinate efforts to support patients experiencing long-COVID. Common symptoms of long-COVID include fatigue, cough, shortness of breath, muscle and joint pain, chest pain, loss of taste and smell, difficulties in thinking or concentrating (“brain fog”), depression, anxiety, and abnormal sleep patterns. Of note, these symptoms can occur even in people who had mild symptoms of COVID-19.

Full details on the findings can be found on medRxiv.

About the Study

Data for this analysis were collected from more than one million patient records between February 2020 and May 2021 from Arcadia Data Research (, Burlington, MA), a normalized, de-identified clinical and operational dataset containing over 150 million patient records composed of data from electronic health record (EHR) systems, practice management systems, healthcare payer claims and eligibility data, care management and clinical assessment data, and other third-party sources. Patient criteria included: (1) patient must have been alive as of March 1, 2020; (2) patient must have had at least one encounter with a provider documenting patient history prior to January 1, 2020; and (3) patient must have had at least one encounter with a practitioner who evaluated their health status after January 1, 2020.

About Leavitt Partners, an HMA Company

Leavitt Partners, a leading consulting firm, is at the forefront of navigating change in healthcare by providing a holistic view of economic, market, delivery system, and political influences impacting healthcare. We improve lives by advancing value-based care, striving to make health more accessible, effective, and sustainable. For more information, visit

About the Leavitt Partners COVID Patient Recovery Alliance

Our Alliance is a multi-sector group of leaders across the health care sector marshaling our resources in a coordinated effort to collect evidence, analyze data, and consider an array of resources and support services targeted at patients experiencing long-COVID. With 20 members who are leading organizations across the health care sector, the Alliance is comprised of health care providers, health systems, health researchers, health data scientists, consumer advocates, and others who marshal their resources to leverage data that helps inform the development of models of care and assess the adequacy of current payment structures to ensure individuals with long-COVID can get the care they need to recover and return to full health.

About Arcadia

Arcadia is dedicated to happier, healthier days for all. We transform data into powerful insights that deliver results. Through our partnerships with the nation’s leading health systems, payers, and life science companies, we are growing a community of innovation to improve care, maximize value, and confront emerging challenges. For more information, visit

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