COVID-19NCT05160636
A Study to Look at the Health Outcomes of Patients With COVID-19 and Influenza
An observational study of COVID-19 and Coronavirus Disease 2019, run by Pfizer at 1 site in United States.
Trial summary
The main purpose of this study is to understand: the symptoms of COVID-19 or influenza- health-related outcomes of people with COVID-19 or influenza (influenza only included in updated study analyses) the potential effects of COVID-19 vaccines in people with COVID-19 This study will enroll participants who are: 18… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- COVID-19, Coronavirus Disease 2019, Influenza
- What is being tested?
- COVID-19 Vaccine
- Type of treatment
- Vaccines
- How many people
- 999 participants
- Where
- 1 siteUnited States
- Study dates
- 31 Jan 2022to 31 Jan 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Participants are 18 years or older who are self-reported symptomatic, who tested positive with RT-PCR at any of the approximately 5,000 CVSH COVID-test sites and consented to participate in the PRO study. Updated study analysis included participants 18 years or older who are self-reported symptomatic, with test-confirmed illness when tested at any of CVS pharmacy COVID-19 or influenza test sites, and consent to participate in the study.
Who may be able to join
- Age 18 or older
- Self-reported at least one symptom in the CVS Health pre-test screening questionnaire
- Positive result reported from diagnostic test for COVID-19 (or influenza in updated analysis)
- Evidence of a signed and dated informed consent through electronic consent process indicating that the participant has been informed of all pertinent aspects of the study
- Able to complete the questionnaires by themselves in English or Spanish
Who cannot join
- No symptoms reported in the study screening questionnaire
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Patient-Reported Outcomes Associated With COVID-19 and Influenza: A Prospective Survey Study on Outpatient Symptomatic Adults With Test-Confirmed Illness in the United States
The main purpose of this study is to understand:
- the symptoms of COVID-19 or influenza- health-related outcomes of people with COVID-19 or influenza (influenza only included in updated study analyses)
- the potential effects of COVID-19 vaccines in people with COVID-19
Read more
This study will enroll participants who are:
- 18 years or older
- reported to have symptoms with tests that have confirmed illness. The tests can be taken at any of CVS pharmacy COVID-19 or influenza test sites.
The study will collect vaccine history information from participants who are ready to take part in the study. Participant will be emailed a form with questions about their health related to COVID-19 or influenza during multiple follow-ups over a 6-month period.
Read the detailed description
This is a prospective non-interventional longitudinal cohort survey study. Repeated measures on PROs including: symptoms (prevalence, frequency, duration, and severity), EQ-5D-5L, and WPAI over 6 months will be collected and evaluated.
COVID-19 Cohort: Participants 18 years or older with test-confirmed COVID-19 illness and at least one patient-reported symptom.
Influenza Cohort: Participants 18 years or older with test-confirmed influenza illness and at least one patient-reported symptom.
All study objectives and outcomes will be assessed separately for the two study cohorts. Influenza cohort is only included in updated study analyses.
- Conditions
- COVID-19, Coronavirus Disease 2019, Influenza
- Being tested
- COVID-19 Vaccine
- Keywords
- Patient-Reported Outcomes, Humanistic Burden, Quality of Life, Disease Symptoms Assessment, COVID-19, SARS-CoV-2, Severe Acute Respiratory Syndrome Coronavirus 2 Infection, Acute respiratory infection, Influenza, Human Influenza
- Medical subject headings
- COVID-19, Influenza, Human
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
COVID-19 VaccineBiological
Receipt of Pfizer BioNTech COVID-19 vaccine
| Study group | Role | What they receive |
|---|---|---|
| COVID-19 Positive | Test-confirmed COVID-19 illness and at least one patient-reported symptom Receives: Biological: COVID-19 Vaccine | |
| Influenza Positive | Test-confirmed influenza illness and at least one patient-reported symptom |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Health Related Quality of Life (HRQoL) using EQ-5D-5L
To assess the change in HRQoL using EQ-5D-5L before COVID-19 or influenza and over a 6-month period following the test-confirmed COVID-19 or influenza.
Measured: 6 months
EQ-5D-5L Utility Index (UI) scores
To estimate the EQ-5D-5L UI scores and their change across six time points in a span of six months following the test-confirmed COVID-19 or influenza.
Measured: 6 months
Visual Analog Scale (VAS) scores
To estimate the VAS scores and their change across six time points in a span of six months following the test-confirmed COVID-19 or influenza.
Measured: 6 months
WPAI scores
To estimate the WPAI scores and their change across six time points in a span of six months following the test-confirmed COVID-19 or influenza.
Measured: 6 months
Secondary outcomes (4)
Prevalence and duration of SARS-CoV-2 symptoms
To characterize prevalence and duration of SARS-CoV-2 symptoms before COVID-19 and up to 6 months (acute phase and Long COVID).
Measured: 6 months
Prevalence, Severity, and duration of influenza symptoms aggregated as index score area under the curve
To characterize prevalence and duration of influenza symptoms before influenza and up to 6 months (acute phase and Long Flu). Outcome will be aggregated by assigning a point-scale to the symptom severity and calculating the area under the curve of the severity index score.
Measured: 6 Months
Fatigue before COVID-19
To assess fatigue (using PROMIS questionnaire Fatigue short-form 8a) before COVID-19 and over a six-month follow-up.
Measured: 6 months
Fatigue after COVID-19
To estimate the PROMIS questionnaire Fatigue short-form 8a score and its change across six time points in a span of six months following the RT-PCR confirmed COVID-19.
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Dec 2021
- Study start31 Jan 2022
- Primary completion31 Jan 2027 (estimated)
- Study completion31 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for COVID-19Studies of the same condition, open and under way.
- More trials run by PfizerThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 999 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- CVS Caremark
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05160636
- Sponsor's protocol ID
- C4591034
- Other IDs
- NCT05160636
- Status last verified
- Oct 2026
- First submitted
- 15 Dec 2021
- Last updated
- 29 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.
Publications
Hu T, Lupton LL, Yehoshua A, Cappelleri JC, Gavaghan MB, Welch VL, Lopez SMC, Brathwaite R, Di Fusco M, Sun X. The one-month impact of influenza infection on patient-reported symptom burden among symptomatic U.S. adults with a test-confirmed illness: a longitudinal study. BMC Infect Dis. 2026 Jul 9. doi: 10.1186/s12879-026-13950-y. Online ahead of print.
PubMed 42426637Sun X, Di Fusco M, Lupton LL, Yehoshua A, Alvarez MB, Allen KE, Puzniak L, Lopez SMC, Cappelleri JC. Predictors of Long COVID Among Symptomatic US Adults Testing Positive for SARS-CoV-2 at a National Retail Pharmacy. Healthcare (Basel). 2024 Nov 21;12(23):2321. doi: 10.3390/healthcare12232321.
PubMed 39684943Di Fusco M, Cappelleri JC, Yehoshua A, Craig KJT, Alvarez MB, Allen KE, Porter TM, Lopez SMC, Puzniak L, Sun X. Associations between symptom-based long COVID clusters and long-term quality of life, work and daily activities among individuals testing positive for SARS-CoV-2 at a national retail pharmacy. J Patient Rep Outcomes. 2024 Oct 22;8(1):122. doi: 10.1186/s41687-024-00797-7.
PubMed 39436613Sun X, Di Fusco M, Puzniak L, Coetzer H, Zamparo JM, Tabak YP, Cappelleri JC. Assessment of retrospective collection of EQ-5D-5L in a US COVID-19 population. Health Qual Life Outcomes. 2023 Sep 8;21(1):103. doi: 10.1186/s12955-023-02187-x.
PubMed 37679771
Study at a glance
From the registry record, last updated by the sponsor on 29 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Patient-Reported Outcomes Associated With COVID-19 and Influenza: A Prospective Survey Study on Outpatient Symptomatic Adults With Test-Confirmed Illness in the United States
- ClinicalTrials.gov ID
- NCT05160636
- Acronym / sponsor ID
- C4591034
- Conditions
- COVID-19, Coronavirus Disease 2019, Influenza
- Keywords
- Patient-Reported Outcomes, Humanistic Burden, Quality of Life, Disease Symptoms Assessment, COVID-19, SARS-CoV-2, Severe Acute Respiratory Syndrome Coronavirus 2 Infection, Acute respiratory infection
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 999 participants (estimated)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Collaborators
- CVS Caremark
- Study start
- 31 Jan 2022 (actual)
- Primary completion
- 31 Jan 2027 (estimated)
- Study completion
- 31 Jan 2027 (estimated)
- First posted
- 16 Dec 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The main purpose of this study is to understand:
- the symptoms of COVID-19 or influenza- health-related outcomes of people with COVID-19 or influenza (influenza only included in updated study analyses)
- the potential effects of COVID-19 vaccines in people with COVID-19
This study will enroll participants who are:
- 18 years or older
- reported to have symptoms with tests that have confirmed illness. The tests can be taken at any of CVS pharmacy COVID-19 or influenza test sites.
The study will collect vaccine history information from participants who are ready to take part in the study. Participant will be emailed a form with questions about their health related to COVID-19 or influenza during multiple follow-ups over a 6-month period.
Detailed description
This is a prospective non-interventional longitudinal cohort survey study. Repeated measures on PROs including: symptoms (prevalence, frequency, duration, and severity), EQ-5D-5L, and WPAI over 6 months will be collected and evaluated.
COVID-19 Cohort: Participants 18 years or older with test-confirmed COVID-19 illness and at least one patient-reported symptom.
Influenza Cohort: Participants 18 years or older with test-confirmed influenza illness and at least one patient-reported symptom.
All study objectives and outcomes will be assessed separately for the two study cohorts. Influenza cohort is only included in updated study analyses.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| COVID-19 Positive | – | Biological: COVID-19 VaccineTest-confirmed COVID-19 illness and at least one patient-reported symptom |
| Influenza Positive | – | –Test-confirmed influenza illness and at least one patient-reported symptom |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Participants are 18 years or older who are self-reported symptomatic, who tested positive with RT-PCR at any of the approximately 5,000 CVSH COVID-test sites and consented to participate in the PRO study. Updated study analysis included participants 18 years or older who are self-reported symptomatic, with test-confirmed illness when tested at any of CVS pharmacy COVID-19 or influenza test sites, and consent to participate in the study.
Key inclusion criteria (5 listed)
- Age 18 or older
- Self-reported at least one symptom in the CVS Health pre-test screening questionnaire
- Positive result reported from diagnostic test for COVID-19 (or influenza in updated analysis)
- Evidence of a signed and dated informed consent through electronic consent process indicating that the participant has been informed of all pertinent aspects of the study
- Able to complete the questionnaires by themselves in English or Spanish
Key exclusion criteria (1 listed)
- No symptoms reported in the study screening questionnaire
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| COVID-19 VaccineReceipt of Pfizer BioNTech COVID-19 vaccine | Biological | COVID-19 Positive |
Primary outcome
Change in Health Related Quality of Life (HRQoL) using EQ-5D-5L
Time frame: 6 months
To assess the change in HRQoL using EQ-5D-5L before COVID-19 or influenza and over a 6-month period following the test-confirmed COVID-19 or influenza.
EQ-5D-5L Utility Index (UI) scores
Time frame: 6 months
To estimate the EQ-5D-5L UI scores and their change across six time points in a span of six months following the test-confirmed COVID-19 or influenza.
Visual Analog Scale (VAS) scores
Time frame: 6 months
To estimate the VAS scores and their change across six time points in a span of six months following the test-confirmed COVID-19 or influenza.
WPAI scores
Time frame: 6 months
To estimate the WPAI scores and their change across six time points in a span of six months following the test-confirmed COVID-19 or influenza.
4 secondary outcomes
Prevalence and duration of SARS-CoV-2 symptoms
Time frame: 6 months
Prevalence, Severity, and duration of influenza symptoms aggregated as index score area under the curve
Time frame: 6 Months
Fatigue before COVID-19
Time frame: 6 months
Fatigue after COVID-19
Time frame: 6 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Oct 2026.
- Derived from this study: PubMed 42426637Hu T, Lupton LL, Yehoshua A, Cappelleri JC, Gavaghan MB, Welch VL, Lopez SMC, Brathwaite R, Di Fusco M, Sun X. The one-month impact of influenza infection on patient-reported symptom burden among symptomatic U.S. adults with a test-confirmed illness: a longitudinal study. BMC Infect Dis. 2026 Jul 9. doi: 10.1186/s12879-026-13950-y. Online ahead of print.
- Derived from this study: PubMed 39684943Sun X, Di Fusco M, Lupton LL, Yehoshua A, Alvarez MB, Allen KE, Puzniak L, Lopez SMC, Cappelleri JC. Predictors of Long COVID Among Symptomatic US Adults Testing Positive for SARS-CoV-2 at a National Retail Pharmacy. Healthcare (Basel). 2024 Nov 21;12(23):2321. doi: 10.3390/healthcare12232321.
- Derived from this study: PubMed 39436613Di Fusco M, Cappelleri JC, Yehoshua A, Craig KJT, Alvarez MB, Allen KE, Porter TM, Lopez SMC, Puzniak L, Sun X. Associations between symptom-based long COVID clusters and long-term quality of life, work and daily activities among individuals testing positive for SARS-CoV-2 at a national retail pharmacy. J Patient Rep Outcomes. 2024 Oct 22;8(1):122. doi: 10.1186/s41687-024-00797-7.
- Derived from this study: PubMed 37679771Sun X, Di Fusco M, Puzniak L, Coetzer H, Zamparo JM, Tabak YP, Cappelleri JC. Assessment of retrospective collection of EQ-5D-5L in a US COVID-19 population. Health Qual Life Outcomes. 2023 Sep 8;21(1):103. doi: 10.1186/s12955-023-02187-x.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: No. Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Pfizer CT.gov Call Center study director
Pfizer
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of COVID-19 and Coronavirus Disease 2019, run by Pfizer at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 29 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Health Related Quality of Life (HRQoL) using EQ-5D-5L (time frame: 6 months). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05160636, which also lists 4 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Oct 2026.