Presentations & Webinars

Presentations & Webinars


Long COVID-19 in the Arizona CoVHORT

We (The Arizona CoVHORT Study) hosted a FREE webinar that covered several topics concerning long-COVID including an overview of the condition, the prevalence of the condition and associated symptoms among participants in the Arizona CoVHORT, and an overview of partnering studies also seeking to better understand the condition.

Presenting CoVHORT Researchers Include:

  • Dr. Karen Lutrick Assistant Professor in the Department of Family & Community Medicine at the College of Medicine
  • Dr. Melanie Bell Professor in the Department of Epidemiology and Biostatistics at the Mel and Enid Zuckerman College of Public Health; Head of the Biostatistics and Design core, Center for Health Disparities Research; Vice-Chair of the Statistics Graduate Inter-Disciplinary Program
  • Collin Catalfamo Co-Data Manager for CoVHORT; Graduate Research Associate and Doctoral Candidate in Epidemiology in the Department of Epidemiology and Biostatistics at the Mel and Enid Zuckerman College of Public Health 
  • Dr. Kristen Pogreba-Brown Assistant Professor, Epidemiology and Biostatistics Department at the Mel and Enid Zuckerman College of Public Health

Presenting UArizona Faculty Include:

  • Dr. Sairam Parthasarathy Professor of Medicine at the College of Medicine; Chief, Division of Pulmonary, Allergy, Critical Care and Sleep Medicine; Director, Center for Sleep and Circadian Sciences, UA Health Sciences; Medical Director, Center for Sleep Disorders, Banner – University Medical Center Tucson

Conquering COVID: Celebrating CoVHORT's One Year Anniversary

We (The Arizona CoVHORT Study) celebrated our one year anniversary! The research team hosted a FREE webinar that covered several COVID hot topics including vaccine safety, long-COVID, participant diversity, kids in CoVHORT, and more.


Presenting UArizona Faculty Include:

  • Dr. Kristen Pogreba Brown Assistant Professor, Epidemiology and Biostatistics Department at the Mel and Enid Zuckerman College of Public Health
  • Dr. Velia Nuno Assistant Professor & Program Director, BA in Wellness and Health Promotion Practice
  • Dr. Felina Cordova-Marks Director of Tribal Engagement & Postdoctoral Research Fellow at the University of Arizona’s Cancer Center.
  • Dr. Melanie Bell Professor in the Department of Epidemiology and Biostatistics at the Mel and Enid Zuckerman College of Public Health; Head of the Biostatistics and Design core, Center for Health Disparities Research; Vice-Chair of the Statistics Graduate Inter-Disciplinary Program
  • Dr. Mary-Frances O'Connor Associate Professor and Director of Clinical Training, Department of Psychology
  • Dr. Beth Jacobs Epidemiology and Biostatistics and Nutritional Sciences at the Mel and Enid Zuckerman College of Public Health

Presenting ASU Faculty Include:

  • Dr. Megan JehnAssociate Professor of Epidemiology at the School of Human Evolution and Social Change

Answers to Missed Questions

Unfortunately, we weren't able to address all of your questions in the Live Q&A. We do appreciate all of the questions we received! We've included answers to common questions we weren't able to answer live below organized by theme.

Will this study give us data that shows how long the vaccine provides antibodies over time? What about antibody load?

No, the CoVHORT study does not take regular blood specimens that would allow us to test for antibodies over time. There is another study on campus, the HEROES study, that is looking at antibody status in those infected and vaccinated. 

Do the antibody tests detect both disease response and vaccine response? Can the tests distinguish between the two?

Antibody tests can be designed to detect different proteins. Most antibody tests target the spike protein. The spike protein is found on both vaccine antibodies and natural antibodies.  Some antibody tests look for antibodies to parts of the virus that are not vaccine targets. These antibody tests will only pick up past infections (natural antibodies). Finally, some antibody tests test for both of these components. 

What is the minimum age required for an individual to be antibody tested?

An individual of any age can be tested for antibodies; however, very young children may experience more discomfort during the blood drawing process. 

How long do COVID-19 antibodies last?

It is not known just how long antibodies persist; however, studies indicate that they may persist over one year. Other scientists speculate that antibodies may persist for life. 

Do I need to be vaccinated if I still have antibodies from a natural infection?

Even if you still have antibodies, we still highly recommend receiving the vaccine. Often, the immunity you gain from an infection is tailored towards that specific strain of the virus. The vaccines cause your immune system to generate protection to a broad selection of possible strains; so they better protect you from possibly developing COVID a second time.

What are the prospects for achieving herd immunity?  Will we need to only achieve that benchmark amongst elderly and vulnerable populations?

This depends on the geographic area in question. Certainly, there will be some communities that will achieve high enough levels of immunization to prevent significant outbreaks. However, there are some parts of the US that have very little chance of achieving herd immunity through vaccination. Unfortunately, some of these communities with high vaccine refusal may end up achieving herd immunity through infection with COVID, which will certainly lead to increased mortality and hospitalizations in the process.

What is known about the impact of COVID-19 on small children, premature children, and children with underdeveloped immune systems?

While serious illness is quite rare in most children, there is higher risk for very young infants and those with lower immune status due to underlying health conditions. To date 335 deaths have been reported in children in the United States - or 0.01% of child cases. Over 16,000 children have been hospitalized - or 0.9% of all child cases. While this is low, there is definitely risk to children. New variants are more transmissible and may cause more serious illness for children. Until vaccination is available for young children, they and their families should continue to take recommended precautions.

Are there any known long-term effects in teenagers that have had COVID?

Some teens have gone on to suffer from long COVID such as shortness of breath that persists for weeks following infection. Teens rarely suffer from multi-system inflammatory syndrome (MICS).

How will I know if I've filled out all of the applicable CoVHORT surveys, or if I've missed one?

You can search for "CoVHORT" in your inbox to find any unopened survey invitations; and don't forget to check your spam or junk folders! You are also welcome to email us at and we will be happy to check the status of your participation.

What percentage of participants have dropped out and joined the CoVHORT study along the way?

We are actively recruiting participants for this study, so all have been recruited along the way. Since we are actively recruiting, we have not assessed drop outs at this time.

Are the results of this study being shared with the CDC, and is the CDC study being shared with our region?

CDC tracks many different studies. In addition, one of our faculty investigators is also on a CDC study and shares information back and forth.

What info can I give to a friend or family to participate, for both adult and child participants?

You can encourage your friends and family to visit the Arizona CoVHORT Study website:

Will this study give us data that shows how long the vaccine provides antibodies over time? How about antibody load?

Our study is not monitoring antibody duration, but other studies at the UA are and they show at least one year or longer for antibody persistence.

How many of the participants are vaccinated?

At least 4,215 of our participants have received at least one dose of a COVID-19 vaccine.

Are results of the CoVHORT study getting to the medical community in Arizona, especially providers to help them understand long-term COVID impacts? Will study results be available to places like Banner, TMC, etc.?

Absolutely. We are working on sharing our results to the research and healthcare community as often as possible and will be publishing our results in academic journals. It is our hope that the information we learn from you will help guide how long COVID is treated and screened for within the community.

Is CoVHORT looking at the connection between the State of Arizona’s policies related to COVID-19 and the beliefs and behavior of our community members?

Yes, we are!

How many participant got COVID-19 after being vaccinated?

VERY few, but we are continuing to collect this data over time.

How are long-haul COVID-19 cases currently being treated?

Long COVID is complex and highly variable. Our understanding of how to treat it is still evolving. However, long COVID clinics are beginning to open; and happily, many long haulers feel much better following vaccination.

Are there any long-COVID treatment/research centers open to us here in AZ?

Our group is just now starting to collaborate with a long-COVID clinic in Phoenix, and another in Banner that is just getting started. We are working with them to post information on how to contact them on our website.

Do you anticipate the U of A creating a Long-COVID Clinic to test Long Haulers and facilitate treatment or research towards treatment?

There is currently a long COVID clinic at U of A. It is run by Dr. Marilyn Glassberg.

As vaccinated individuals, when can we stop wearing masks?

The CDC is updating their guidance on wearing masks for vaccinated individuals as more information is made available. You can go to this website: to see the latest information!

Where can I find a reputable published review of mask efficacy?

Masks are safe and effective. Masks may help prevent people who have COVID-19 from spreading the virus to others. The CDC has guidance for wearing masks. Wearing a face mask may limit exposure to respiratory droplets and large particles and may help prevent people who have COVID-19 from spreading the virus. Here is a systematic review of mask efficacy with additional details:

Is asymptomatic transmission, including in vaccinated individuals, something to be concerned about?

Asymptomatic transmission appears to be quite rare (with the current variants circulating) when someone is two weeks past their full dose, particularly for the Pfizer and Moderna vaccines. Even if there is a break-through infection, viral loads are lower in vaccinated individuals. However, if an individual is known to have been exposed to COVID-19 and they are around individuals of high risk, it is better to err on the side of caution and wear masks and take other common-sense precautions.

It is also important to note, although there is a substantially lower risk of transmission in vaccinated individuals, there is still some risk. It would take 1) a break-through infection, and 2) having enough virus to transmit. While the risk is greatly reduced, especially if both people are vaccinated, it is still possible and there is evidence that in immune compromised individuals (e.g., a transplant recipient) the vaccine might not work quite as well, but still provides some protection."

Has there been evidence of fomite transmission of COVID-19?

This appears to be possible, but not a common route of transmission. It is not necessary to wipe down groceries, for example.

What is the probability of having asymptomatic COVID and passing it on to an unvaccinated toddler?

It is certainly possible. If the person is not vaccinated, the likelihood is much higher. If they are vaccinated and end up with an asymptomatic infection, the risk is still not zero, but it is far, far less.

If the Pfizer and Moderna vaccines were developed with similar methods, why are their reactions so different?

The biological mechanisms behind why one may elicit more side effects than the other, even though both vaccines are mRNA based, could be due to a couple of different things: 1. Moderna's dose contains more than 3 times the amount of mRNA than Pfizer's dose, and 2. Each vaccine uses different nanolipids to house their mRNA. Both of these molecules (the mRNA and nanolipids they are contained in) act as adjuvants in addition to their other functions. Adjuvants enhance the immune system's response to antigens, helping to set off the chain of responses that leads to your immune system being able to recognize and respond more quickly to it in the future. It could be that the increased mRNA in Moderna's vaccine and/or the different nanolipid used result in a stronger initial immune response to the vaccination, which is responsible for the side effects people start to experience ~12hrs post injection.

How fatal is the vaccine versus COVID-19?

There is no comparison. Thus far there have been three deaths that appear to be related to blood clots from the J&J vaccine. These are the only deaths that appear to be related to vaccination. There have been over 330 million doses administered. By contrast, there have been 37 million documented cases of COVID-19 and over 600,000 deaths. This is a staggering contrast that illustrates vaccines are exceedingly safe in comparison to getting COVID-19.

What are the most common symptoms/complications of contracting the SARS-CoV-2 virus versus getting vaccinated?

The most common symptoms of COVID-19 include fever, shortness of breath, loss of sense of taste and smell, cough, fatigue, headache, sore throat, nausea and diarrhea. Hospitalization and death is much more likely from natural infection, than from the vaccine, especially in individuals with weakened immune systems.

Are there many participants in your antibody studies that are on immunosuppresant drugs that the vaccine has not worked for? Is this something you are looking at?

The Arizona CoVHORT does not collect blood samples or other biological specimens to measure individuals' responses to vaccination. We are currently unaware as to whether other studies that are collecting blood samples to measure responses to vaccination are looking at this specifically.

How are individuals affected differently if they first had a severe COVID-19 infection and then received the vaccine following their infection?

Most people who had COVID-19 and then go on to get vaccinated do just fine. There is some evidence that the reaction may be a bit stronger, with individuals feeling poorly for a day or two more.

What are the main differences between the J and J vaccine (one-dose vaccine) and Moderna and Pfizer (two-dose vaccines)?

The CDC has provided a great resource for understanding the similarities and differences between the 3 vaccine options. You can find more information here.

Have we established a causal relationship between vaccination rates and rates of infection and/or spread of the disease?

In Arizona, as more people have gotten the vaccine, we are seeing less COVID-19 cases. For example, a few months after the vaccine was made available to the Phase 1 groups, we saw a decrease in cases in this population. Recently, we saw a rise in children 12-18 years, but now that the vaccine is available to them, we are seeing a sharp decline as well!

Does receiving the second dose of Pfizer at an interval of 20 days rather than 21 days affect effectiveness?

No. Other areas of the world have used different vaccine schedules and have shown an equivalent immune response compared to the standard 21 day vaccine schedule for Pfizer. 21 days is still preferred, but 20 days should not make a significant difference.

How long will the vaccination last? Is there any information on needing a booster shot for those vaccinated early on?

There are clinical trials going on right now which are looking at the need for a booster; however, there is not enough information at the moment for us to know whether we will need a booster or a yearly shot moving forward. What we do know from the clinical trials, which followed vaccinated participants, is that the Moderna and Pfizer vaccines confer a strong immune response 9 months after vaccination! We are hopeful that this immunity will continue for longer as well.

Do you have any information on people getting symptom relief once they are vaccinated?

Yes! There have been a few case studies (which is a description of a single person) which show improvement, or complete resolution of long-COVID symptoms after vaccination. We still need more research in this area, but this is very exciting!

Have there been side effects from the vaccine in children ages 12-18 years?

During clinical trials, the most common side effects for children ages 12-18 years were tiredness, fever, and feeling achy.

Are there any long term effects we should be worried about after receiving the vaccine?

No. The COVID-19 vaccine is a safe and effective vaccine, and the benefits of the vaccine are numerous.

Could you tell more about COVID vaccine swelling that supposedly is causing false positives on cancer screening exams?

In the clinical trials for the the Moderna vaccine, axillary swelling or tenderness was reported in 11.6% of patients (5% with placebo) after dose 1, and 16% (4.3% with placebo) after Dose 2. A recent case study (which means a description of one patient only) showed a lymphadenopathy after being vaccinated for COVID-19, which appeared on a mammogram screen ( This is where this statement originated, but it does not show that the vaccine will cause false positives on cancer screening exams because it was one person, and more research is needed. Lymphadenopathy is a swelling of the lymph nodes. This is a sign of the body's immune system gearing up in response to the vaccine and will go away often within a few weeks. Patients who are concerned about potential swelling should seek care from their primary care doctor.

Can children under 16 years be vaccinated?

Yes. Any person, 12 years and older, can now get the COVID-19 vaccine.

Is there any mechanism for students under 18 (12-17 year olds) to get vaccinated who want to get vaccinated; however, their parents are anti-vaxxers?

This is a tough situation. Any person, 12 years and older, can now get the COVID-19 vaccine with an adult present. We would recommend talking with the parents of the child if you have a close relationship, and helping to advocate for the child if they are interested in getting it, but their parents are not.

Will COVID-19 vaccinations become seasonal?

This is currently unknown in terms of seasonality. I don’t think we have yet settled into a predictable seasonal pattern. In the future, it may have a more predictable pattern and seasonality like influenza.

Is the COVID-19 vaccine safe for children 12-16 years, who have medical issues that are of concern?

While the vaccine appears to be VERY safe for children (both of my kids have now gotten their first dose), it is best to go with their pediatrician's recommendation.

Are teens expressing challenges where they want to get vaccinated but their parent(s) will not allow it?

There have been some stories about this. It is important that we provide accurate information to parents so they can make informed decisions about getting their children vaccinated.

How can we deal with COVID-19 anxiety as we return to "normal," eg. returning to the workplace and trying to reconnect with friends we grew apart from during the pandemic?

Change is hard, and this has been a year of constant change. Going back to work is not the same as going back to the way things were “in the before times.” The best way to address anxiety is to take it in small steps. For a person who is extremely nervous, simply going to work and parking (maybe walking to your office), may be a good first step. Go in for a short time, throw out your unwatered plants, and say hi to one or two colleagues. Associate going in with something positive! Take a new photo you love to work, or get your favorite coffee drink when you go in. Taking it slow and being compassionate with each other, we will get to a new normal.

Can plasma be donated following infection and vaccination?

From the Red Cross: “The American Red Cross is testing all blood, platelet, and plasma donations for COVID-19 antibodies. As part of that effort, plasma from whole blood donations that test positive for COVID-19 antibodies may now help current COVID-19 patients in need of convalescent plasma transfusion.

As hospitals resume surgical procedures and patient treatments that were temporarily paused due to the COVID-19 pandemic, donors are urged to give now to ensure blood products are readily available for patients."

Last year,  there were studies that showed blood type and COVID-19 symptom severity may be related. Are there any studies available to support this?

Early on, there were studies that indicated Blood Type O was less susceptible, and Blood Type A was more susceptible. However, a recent review of these studies and compilation of evidence suggests there is no relationship.

COVID-19 Vaccines and Reproductive Health

In this presentation, our own Dr. Leslie Farland, MSc, ScD;reviews the recent data regarding COVID-19 vaccines and reproductive health, fertility, and pregnancy outcomes. Conclusion: COVID-19 vaccination does not negatively influence fertility or pregnancy outcomes. Learn more below!

The University of Arizona Health Sciences

COVID-19 Symposium

Our two-day event was filled with exciting talks about COVID-19 research efforts. We had approximately 20 scientific presentations highlighting the broad array of work being conducted by our colleagues at the University of Arizona and throughout the state. In addition to the science, this symposium included experiences and presentations designed to bring us together as a community. Each day, we were fortunate to have Mr. Miguel Flores conduct a traditional blessing. On Tuesday, Ms. Nyona Smith, of the Tohono O’odham Nation, virtually performed a jingle dress dance during lunch. A full list of the presentations can be found below.

  • Keynote Address: Pima County COVID-19 Response
    Francisco García, MD, MPH
  • CoVHORT: Building the University of Arizona COVID-19 Cohort
    Kristen Pogreba-Brown, PhD
  • A Retrospective Evaluation of District Openings Amid COVID-19
    Theresa LeGros, MA
  • "DASH-SAFE": A personal real-time risk-assessment, risk-management, navigation and automated alarm tool
    Esther Sternberg, MD & DASH Team
  • Workplace Safety and Mental Health Distress among Grocery Store Workers during the COVID-19 Pandemic
    Brian Mayer, PhD
  • Inclusive Policymaking Tools: A COVID-19 Case Study
    Celina Valencia, DrPH
  • Testing Effectiveness of Behavioral Interventions to Improve Mask Compliance Among College Students
    Anastasiya Ghosh, PhD
  • Intention to vaccinate during the “twindemic”: influenza and COVID-19 vaccine decision making in adult residents of Pima County, AZ
    Maiya Block
  • Genomewide Association Study of COVID-19 Severity
    Mario Trejo, MPH
  • COVID-19 and Aging
    Mark Wager & Zhao Chen, PhD
  • Raising Families and Returning to UArizona: A COVID-19 Re-entry Study
    Madeleine deBlois, Sc.D
  • Pilot Testing an App-Based Meditation Intervention Among Firefighters During the COVID-19 Pandemic
    Evelyn Sarsar
  • Keynote Address: The Tohono O’odham Nation’s COVID-19 Response and Experience
    Wavelene Saunders, Vice Chairwoman, Tohono O'odham Nation
  • American Indian Research Center for Health COVID Prevention Outreach to Tribal and Urban AIAN Communities
    Teshia Solomon, PhD
  • CoVHORT: Tribal Engagement in the University of Arizona COVID-19 Research Program
    Felina Cordova-Marks, DrPH, MPH
  • Tucson Indian Center's Community Response to COVID-19
    Drew Harris
  • University-Community Research Response to COVID-19 Amplified Food, Energy, and Water (FEW) Insecurities on the Navajo Nation
    Karletta Chief, PhD
  • Impact of the COVID-19 Pandemic on Navajo Adults and Health Care Providers
    Heidi Brown, PhD
  • Community Engagement Alliance (CEAL) Against COVID-19 Disparities: An Overview of Tribal Engagement for the Arizona CEAL
    Samantha Sabo, DrPH, MPH & Naomi Lee, PhD
  • Lunch Break & Virtual Performance
    Nyona Smoth, Tohono O'odham Nation
  • Association between blood type and COVID-19 susceptibility in Arizona
    Ateefa Rashid
  • Surveillance of COVID-19 Related Xenophobia among Arizonan University Communities & Healthcare Communities in the United States: Driving Factors and Magnitude of Prejudice, Discrimination, and Racial Tension
    Coco Gomez Tirambulo & Caitlyn McFadden
  • AZ HEROES Study
    Maiya Block
  • Keynote Address: The Pascua Yaqui Tribe’s COVID-19 Response and Experience
    Herminia Frias, Councilwoman, Pascua Yaqui Tribe

Become part of the solution!

Fight the virus, join the CoVHORT