Arizona Household Virus study

Thank you for your interest in the Arizona Household Virus study!
Researchers at the University of Arizona are investigating the transmission of COVID-19 within households. Scroll down to learn more about the study and eligibility.

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Households provide excellent environments for influenza, SARS-CoV-2, and other respiratory viruses to transmit, because close contacts among household members are common and the household environment is generally considered ‘safe’ by household members. Indeed, much of our understanding of influenza transmission, its patterns and timing, comes from household-based studies because the household provides a strategic setting to track influenza infections among close contacts of cases. Early household transmission studies led by CDC, the Marshfield Research Clinic Institute and VUMC investigators have provided important data on the transmission of SARS-CoV-2 within US households Although vaccines are recommended for prevention of influenza and SARS-CoV-2 related disease, the effectiveness of vaccines to prevent transmission is unclear. Rapid assessments of patterns of infections and viral transmission, how these patterns are affected by available vaccines or treatments, virus types, duration and type of contacts, and other factors, are necessary for public health and vaccination policy recommendations. Therefore, CDC and FDA are sponsoring a new network of US sites to conduct a multi-center evaluation of the effectiveness of influenza and SARS-CoV-2 vaccines for preventing transmission of infections in households.

Understanding whether recommended vaccines are effective in preventing infection among exposed individuals or reducing the chance of passing the infections to others in close contact is of great public health interest, but this is currently unknown. Households, where individuals share common areas and usually interact in close proximity provide an optimal venue to study viral transmission. Case-ascertained designs, where household members are enrolled and observed after a first household member is known to be infected, provides efficient opportunities to assess the impact of vaccination on viral transmission. To maximize efficiency and generalizability of findings, multi-center studies are warranted. The Arizona Household Virus study (AZ-HVS) will function part of a national multi-center evaluation of influenza and SARS-CoV-2 vaccines for preventing transmission of infections in households. Sites will implement a standardized intensive case-ascertained design with daily collection of data and specimens to determine the effectiveness of vaccination on reducing transmission of viral infections within households. Because of the pandemic and as required by CDC and FDA, findings from these activities will be shared with these public health agencies in a timely manner, to inform public health decision making and vaccination policies.

1. Estimate attack rates of SARS-CoV-2 and influenza virus infection among household contacts

2. Estimate attack rates of SARS-CoV-2 and influenza virus infection among household contacts of vaccinated and unvaccinated index cases to estimate the impact of vaccination on transmission.

3. Estimate attack rates of SARS-CoV-2 and influenza virus infection among vaccinated and unvaccinated household contacts to estimate the impact of vaccination on the risk of infection and disease manifestations.

4. Identify individual-level and household-level factors associated with increased or decreased risk of SARS-CoV-2 and influenza virus infection and transmission in households.

1. Study staff will contact COVID-19 positive individuals within 48 hours of the individual being tested.

2. On the same calendar day that they enroll, participants will receive study materials.
Starting with the day they enroll, study participants will be asked to complete a single acute blood sample using a finger-prick devise and a nasal swab.

3. For the next nine (9) days, participants will collect nasal swabs and complete brief daily questionnaires

4. Study staff will collect samples at each household a minimum of every 2 days.


Household members may receive compensation for their participation in the study. We will provide the household up to $150 for the collection of the daily nasal swabs, and up to $50 for the initial finger prick blood collections for up to $200 for the requested data and complete samples collected during the initial 10 days of enrollment. Households that participate in the additional home-test may receive up to an additional$150 at the end of the ~10-day follow-up. An additional $50 will be the compensation for the 4-6 weeks assessment including a single follow-up finger prick blood collection from household participants and an additional $25 for data on productivity losses. Households that participate in the 12- week assessment will receive an additional compensation of $25 Thus, for a household that participates in all data and sample collections, the total household compensation will be for up to $450 (per household).

Enrollment: https://bit.ly/azhvs
Email: AZHVS-ArizonaHVS@arizona.edu
Phone: 520-621-8357


As individuals test positive, the study team will first verify that they are the first at that address to test positive for COVID-19 or Influenza. If they are, they will then enter them into the study REDCap database as a potential participant. Eligibile subjects will meet the following criteria:

  • Tested positive for COVID-19 and/or influenza;
  • Currently live with someone who is not yet sick 7 days prior to or on the same day of symptom onset/COVID infection; and
  • Able to read English or Spanish. Participants will be excluded if they live in a correctional facility, long-term care facility, or other institutional setting.

Enroll in this study

Our Team


Katherine Ellingson, PhD

Co-Principal Investigator

Katherine Ellingson is an Assistant Professor in the Department of Epidemiology and Biostatistics at the University of Arizona. Her research interests include patient safety, occupational safety, infection prevention, antibiotic resistance, and outbreak response (e.g., H1N1, Ebola and Zika). Having served as both a EIS officer and Senior Epidemiologist at the CDC and Oregon Health Authority, her work emphasized improvement of public health systems through applied research. 


Karen Lutrick, PhD

Co-Principal Investigator

Karen Lutrick is an Assistant Professor in the Department of Family & Community Medicine at the University of Arizona. Her research interests focus on disaster medicine research, research operations, health disparities, dissemination and implementation science. She is also the Director of the National Foundation of Emergency Medicine, supporting Emergency Medicine physicians in developing translational research skills throughout the US.


Saskia Smidt

Clinical Research Coordinator


Karla Ledezema

Clinical Research Coordinator


Ferris Ramadan

Data Management