Ask the Expert

Yes, infected people can transmit the virus that causes COVID-19 even if they do not have any symptoms. That is why it is so important that if you test positive for COVID-19, regardless of symptoms, you follow the isolation guidelines on the UCI Forward page to break the chain of infection and reduce the spread of COVID-19.

On Friday (Nov. 26), the World Health Organization designated COVID-19 omicron as a variant of concern based on evidence that the omicron variant has several mutations that may have an impact on how it behaves; for example, how easily it spreads or the severity of illness it causes. The variant was first detected in South Africa and has since been detected in a number of other countries, though not in the United States. Public health experts do, however, believe it will be detected in the U.S. as well. 

It is not yet clear whether omicron is more transmissible compared to other variants, including delta, or whether it causes more severe disease. The number of cases has risen in areas of South Africa where omicron is present, and epidemiological studies are underway to determine if this increase is because of omicron or other factors. The WHO and public health experts are working to understand how effective current vaccines and detection tests are for omicron. PCR tests continue to detect infection, including infection with omicron, and studies are ongoing to determine whether there is any impact on other types of tests, including antigen tests.

There are no changes to current campus policies or plans at this time. While public health experts continue to learn more about omicron, this serves as a good reminder for all of us to get vaccinated against COVID-19 and flu, and get those around us vaccinated and to get your COVID-19 booster dose when you are eligible to do so. Remember, all adults are eligible for boosters six months after their second dose of Pfizer or Moderna and two months after the single Johnson & Johnson dose.  Remember to complete your daily symptom check, stay home if you are ill and get tested for COVID-19 if you have symptoms regardless of your vaccination status. If you will be traveling, be sure to check and follow CDC travel guidance for pre- and post-travel recommendations.

Answered by David Souleles, director of UCI’s COVID-19 Response Team

One dose is better than no dose. I anticipate children, even after one dose, will have a pretty strong protection, but you will need that second dose to get you closer to 100%. Also taking into consideration different individuals, children who are immunocompromised or who have underlying conditions that may reduce their response to the first dose — in general, starting the series sooner rather than later is best, especially going into the holiday season.

Answered by Dr. E.R. Chulie Ulloa, assistant professor of pediatric infectious diseases

Featured in The Washington Post

The CDC and the California Department of Public Health have recommended and the University of California has required universal indoor masking regardless of vaccination status in communities with substantial to high levels of community transmission per CDC standards. As of Oct. 7, Orange County is at a substantial level of community transmission per CDC, whose guidance applies to the weekly not daily case rate. For the seven days ending on Oct. 6, the CDC had Orange County at 62.57 cases per 100,000. (See this link.) UCI must also comply with Cal OSHA COVID-19 Emergency Temporary Standards related to the use of face coverings in the workplace.

As the community transmission level decreases, the campus will evaluate updating campus directives on face coverings taking into consideration campus and community case rates and testing positivity rates, UC systemwide guidance, and Cal OSHA COVID-19 Emergency Temporary Standards.

Answered by David Souleles, director of UCI’s COVID-19 Response Team

Lessons should be cognitively demanding as opposed to rote learning. I recommend beginning instruction by asking students, “Did delta have to happen?,” which promotes thinking about why viruses evolve, how humans currently give plentiful opportunities for viruses to mutate and what actions people can take to help. Having children investigate and make an argument would be a valuable learning opportunity.

Answered by David Souleles, director of UCI’s COVID-19 Response Team

I doubt we'll make it through the winter without another surge, but the height will be heavily mitigated by vaccines and boosters. Here in California we have hope for a smaller wave (maybe the same as what we just experienced) vs. less vaccinated states ... I think it's highly unlikely that it's all downhill from here, but that may be a real possibility in the spring.

Answered by Dr. Susan Huang, medical director of epidemiology and infection prevention for UCI Health

Face coverings can be removed while an individual is eating or drinking indoors on UCI-controlled property, but if you are not fully vaccinated, you must stay at least 6 feet apart from other individuals.

Answered via UCI’s Executive Directive on face coverings

There are many reasons you should be vaccinated, even with reports of breakthrough infection with the delta variant.

• First, vaccination is the only protection you have after you’ve been exposed and the virus enters your body through your eyes, nose or open mouth. Vaccination gives you an army in your body that is ready to fight any COVID-19 virus that enters. This includes both antibodies and fighter cells that recognize the virus and attack it. This is why vaccinated people are far less likely to become infected with delta virus (about one third as likely as unvaccinated persons).

• Second, because vaccinated persons are less likely to become ill, they protect those around them. While vaccinated persons can become ill and shed a lot of virus, it remains to be seen whether the virus that vaccinated people shed may be less contagious than the virus shed by unvaccinated ill persons.

• Third, vaccination provides near perfect protection against severe disease, including hospitalization and death. The truth is no one thinks they are going to get severe disease until it happens. The vaccine protects you from the worst kinds of outcomes from this virus.

• Finally, vaccination can be very convenient. More and more workplaces, performances and social events are requiring proof of vaccination.

Answered by UCI Health

The vaccines do not cause infertility or affect any of our genetic code. The COVID-19 vaccines do not enter the part of the cell where DNA is housed, and do not and cannot affect our genetic material. In addition, the vaccine only stays in the body very briefly and is taken up by the cells in our arm. It does not move from the arm to the reproductive organs. During the vaccine trials, when participants were asked to refrain from becoming pregnant, over 20 people who received the vaccine became pregnant during the trials, suggesting the vaccine does not cause infertility. If you are pregnant when you receive the vaccine, the vaccine ingredients do not cross the placenta. The only thing that crosses to the baby are the protective antibodies that your body makes in response to the vaccine. Over 150,000 pregnant people in the U.S. have chosen to receive the COVID-19 vaccine and, so far, there is no evidence of infertility or harm to the baby.

Answered by UCI Health

The currently approved vaccines are highly effective at reducing severe illnesses and hospitalizations for COVID-19, but they do not prevent 100% of such cases. So hospitalizations with severe illness have indeed occurred among fully vaccinated people. From the latest research studies, it seems that severe COVID-19 illnesses among fully vaccinated people are more likely to occur among people who are immunocompromised or have underlying conditions such as chronic lung disease and cancer. So, if community incidence of COVID-19 remains high, there will be a greater chance of vulnerable people getting infected and developing severe illness even though they are fully vaccinated. This is why it’s important for everyone to work together to reduce COVID-19 in the community by avoiding crowded indoor gatherings, improving ventilation in our buildings, masking and getting vaccinated.

Answered by Sanghyuk Shin, associate professor of nursing and director of the UCI Infectious Disease Science Initiative

Students who received a vaccine in their home country that does not meet the UC COVID-19 Vaccine policy requirement, must receive an FDA-approved COVID-19 vaccine upon arrival into the U.S. and complete the series to meet compliance. 

But there may be a waiver period depending on when they received their last dose. This student should go to the Student Health Portal and submit for a “medical exemption” with the reason of “recent vaccination” with “non-approved vaccine.” If possible, they should have their provider sign the dates they were vaccinated. As a reminder, all students should upload any COVID-19 vaccines they have received through their student portal.

UCI’s Contact Tracing and Vaccine Navigation Services can also assist international students with issues related to vaccine documentation and answer questions as to whether vaccines received internationally meet the UC COVID-19 vaccine policy requirements. Students who have questions about the timing or safety of receiving another COVID-19 vaccine so soon after their home country vaccine should ask CTVNS for clarity, and may be asked to submit a Request for Medical Exemption. CTVNS can be reached at contacttracing@uci.edu.

Answered by by Dr. Albert Chang, M.D., M.P.H., Medical Director of UCI’s Student Health Center

Emergency Paid Sick Leave ends on Sept. 30; we have no indication from the UC Office of the President that the leave will be extended. In March 2021, the University offered all employees, including exclusively represented employees, a new 2021 allotment of Emergency Paid Sick Leave. Full-time employees may take up to 80 hours of EPSL for one of six qualifying reasons, ranging from caring for themselves or others with COVID-19 to caring for dependents because of school closures. As with the prior EPSL allotment, employees receive their regular rate of pay during EPSL. Although the law allows employers to place caps on pay for EPSL, the University decided not to apply these caps. This allotment of EPSL expires Sept. 30. Employees may apply for EPSL at this website.

After Sept. 30, staff employees may utilize leave accruals, such as sick, vacation, PTO or compensatory time off, for leaves related to COVID-19. Additionally, staff employees on leaves longer than a few days should file a leave request via UCI's partner Sedgwick. For long leaves, staff employees may qualify for disability income and should coordinate with Sedgwick and HR.

Answered by Ramona Agrela, chief human resources officer and vice chancellor human resources

The White House is now recommending adults 18 years and above who have completed their two-shot Pfizer/Biontech or Moderna mRNA vaccination series to get a booster. Booster vaccines are expected to be available in late September, pending FDA evaluation and CDC recommendation. Details are still being fleshed out, but it appears that it's going to be first for older adults, residents in chronic care facilities, healthcare workers, and then people who received the vaccine more than six to eight months ago. This was partially motivated by data that suggested a small reduction in vaccine efficacy over time in the vaccine clinical trial data.  

For moderate to severely immunocompromised individuals, booster shots have already been authorized by the FDA and recommended by the CDC for those who have had their second mRNA vaccine at least 28 days prior. This is because studies had shown a diminished production of protective antibodies after being vaccinated for some patients that were immunocompromised. Some data has also shown a sizable increase in antibodies to fight COVID-19 for patients that had received a third shot, including antibodies against the delta variant. Importantly, some data from the UK showed that a longer wait time between doses was associated with larger antibody response, so it is possible that the delay prior to a booster could lead to improved protection.

Answered by by Jonathan Watanabe, professor of clinical pharmacy

We have followed people who received mRNA vaccines, such as Pfizer or Moderna, for about six months so far. The immune response is durable, declining by only about 10% from the peak. Based on our data, it looks like an annual boost — similar to what we expect to get for the flu vaccine — may be recommended. Since this coronavirus is prone to variants, the annual boost may contain a different variant from year to year, similar to the flu shot.

Answered by Philip Felgner, professor in residence of physiology and biophysics, and director of UCI’s Vaccine Research and Development Center

Nearly all research indicates that the current vaccines are sufficient in protecting us from the known variants. The alpha, beta and delta SARS-CoV-2 variants differ in the amino acid sequences of their receptor binding domains (RBD). We checked and found that the mRNA vaccines induce antibodies that bind just as well to all of the different RBD variants. The increase in delta virus case numbers is associated with an increase in virus levels that are shed from delta virus-infected people, and close contacts experience a higher level of virus exposure compared to earlier strains. The original mRNA vaccines protect against severe disease requiring hospitalization; people experience cold symptoms and recover at home.

Answered by Philip Felgner, professor in residence of physiology and biophysics, and director of UCI’s Vaccine Research and Development Center.

To ensure that students can hear and understand instructors clearly, we are enhancing our microphone capacity in all classrooms. This is one of the many classroom improvements we’re making to support a high-quality, healthy learning environment.

Answered by Michael Dennin, vice provost of teaching and learning

The claim that more young people are hospitalized due to vaccine-induced adverse effects than due to COVID-19 illness is factually incorrect. First, vaccine trials clearly showed that the risk of developing severe COVID-19 symptoms that can result in hospitalization is much larger than the risk of developing adverse effects after vaccination. This result holds for all age groups studied — 12 years old and above. Moreover, millions of people, including adolescents, have been vaccinated, but only a very small number of adverse effects have been reported in the Vaccine Adverse Event Reporting System that monitors these events across the U.S. In other words, the more people we vaccinate, the clearer we see that COVID-19 vaccines are safe and effective. So, if you haven’t done so already, vaccinate as soon as you can to protect yourself and your community.

Answered by Professor Vladimir Minin, a statistician and infectious disease modeler

It appears that the SARS-CoV-2 virus has been established as part of the human virome – which is the total collection of viruses in and on the human body – and will persist. The virus has spread rapidly among widely dispersed human populations. It has shown the ability to mutate to fine-tune and sustain the infectious cycle through several cycles of infection in humans and animals. Viral variants have arisen and will continue to appear, and some of these will be more capable of spreading. It’s possible that the virus may become less virulent for humans but, like the common cold coronaviruses, still persist. Finally, precursors of SARS-CoV-1 and SARS-CoV-2 exist in bats and may provide a reservoir for future cycles of human infection.

Research efforts will continue to provide the means to control this virus, as we have done for polio and smallpox, both of which were controlled in the 1950s and 1970s. The principal difference with SARS-CoV-2 is that the virus has an animal reservoir in the Asian horseshoe bat and is capable of reemergence. This is also the case with influenza, which persists in waterfowl and is amplified in swine. The genetics of influenza are dictated by the host, with mammalian strains being selected by passage through the pig. If it’s shown that the SARS-CoV-2 virus – like the flu virus – requires an intermediate host to make the jump from bat to human, then immunization of that host may be effective.

Answered by infectious disease researcher Michael Buchmeier, who has been studying coronaviruses for more than 40 years

Read: What you need to know about the delta variant

The range of responses for a student violating a COVID-related Executive Directive include an advisory letter, warning, disciplinary probation (for anywhere from one quarter to duration of enrollment), suspension (for any length of time) or dismissal. We can use an interim suspension for an immediate safety concern, which removes the student from the campus but not any remote classes, for the duration of the investigation and any appeal process. We had about 900 cases last academic year.

Answered by Kim Burdett, director, Office of Academic Integrity and Student Conduct

No. Because plexiglass barriers don’t extend to the ceiling (or to the ground at the entrance to a cubicle), and therefore don’t create an enclosed space. So you’ll still be required to wear a face covering.

Answered by the Campus Recovery Implementation Team

We expect booster shots will be needed before the winter wave as people’s immunity starts to wane about nine to 12 months after being vaccinated. Just last week, the FDA authorized immunocompromised persons to receive an extra (third) dose of the Pfizer or Moderna vaccine to help generate a stronger immune response. In addition, we expect Pfizer and Moderna to request FDA authorization for a third dose for other groups beginning in September. The booster would be the exact same dose as the prior vaccines and would only be available to those who already received that type of vaccine. We know there is quite a bit of mixing and matching of vaccines in other countries, so it remains to be seen whether that will happen here as more evidence emerges. I know many people who received the J&J vaccine would like to receive a dose of Pfizer or Moderna, so stay tuned. These are hot topics and more is coming.

Answered by Dr. Susan Huang, director of epidemiology and infection prevention

In December of this year, the CDC is planning to retire its own original PCR diagnostic test that it developed at the very beginning of the pandemic. This is because the FDA has authorized hundreds of other SARS-CoV-2 diagnostic tests with higher throughput that can test for more than one illness at a time. The original test is not being withdrawn because it produced too many false positives.

Answered by Philip Felgner, professor in residence of physiology and biophysics, and director of UCI’s Vaccine Research and Development Center. Professor Felgner recently won a prestigious award for his contributions to designing COVID-19 vaccines.

A certain number of false positives are to be expected, and as the prevalence of COVID-19 declines, the percentage of false positives increases. At the same time, the positive predictive ability of the PCR test declines. Where PCR tests are especially useful is to confirm COVID-19 in the subgroup of symptomatic individuals. This is a group where the prevalence of true COVID-19 is higher than in the population as a whole.

(Read more at FactCheck.org.)

Answered by Philip Felgner, professor in residence of physiology and biophysics, and director of UCI’s Vaccine Research and Development Center. Professor Felgner recently won a prestigious award for his contributions to designing COVID-19 vaccines.

For those not vaccinated it may be for several reasons. In research I’ve worked on, we’ve learned from discussions with parents about vaccinating their kids that there is high complacency about the risk of COVID-19 and low confidence in the vaccine. Messaging needs to build confidence in the effectiveness of the vaccine, and remind people that choosing not to vaccinate is riskier than vaccinating. We also need to make it as easy as possible for people of all backgrounds to get the vaccine, by, for instance, allowing them to take a couple days off work to vaccinate and rest without fear of losing their jobs. The key message is that we are all in this together and the more people who vaccinate and mask up inside for now, the quicker we can all get out of this horrific pandemic. It is a collective risk and we are dependent on each other.

Answered by by Suellen Hopfer, assistant professor of public health and expert on vaccine hesitancy

The UC Office of the President and UCI leadership have made a commitment to return to full in person work, learning and research for the fall quarter in order to support all of our students in their educational endeavors. This decision was not made lightly and was made in alignment with current federal, state, and local public health guidelines and mandates.  These guidelines and mandates are meant to assure the campus is as safe as possible with the return to in person learning given the current state of the COVID-19 pandemic. 

Here at UCI, we have a number of risk reduction measures that layer together to reduce the risk of transmission of the virus that causes COVID-19. These include:

• A COVID-19 Vaccine policy requiring all students, staff, and faculty to be fully vaccinated or have an approved exception or deferral in order to access university property or programs.  Vaccination is one of the most important tools we have to reduce the risk of COVID-19
• A Chancellor’s Executive Directive requiring universal indoor masking regardless of vaccination status for all students, staff, faculty, and visitors to the campus
• Mandated daily symptom checking and reporting for all students, staff and faculty, with COVID-19 testing arranged for those who are symptomatic.
• Mandated weekly asymptomatic testing for those who are unvaccinated or partially vaccinated
• Onsite case investigation and contact tracing services to quickly identify cases and close contacts and arrange for isolation and quarantine as appropriate

University leadership is continuously reviewing case trends on campus and in the community and public health guidance and recommendations, as well as consulting with local and state public health officials on risk reduction measures and will continue to monitor and adjust measures throughout the academic year as needed.

Answered by David Souleles, director of UCI’s COVID-19 Response Team

As we know, the virus is primarily spread from person to person among those in close contact through small droplets or aerosols that stay in the air for minutes to hours. When you're outside, fresh air is constantly moving and dispersing these droplets, thereby diluting the virus concentration, and making it less likely to breathe in enough of the respiratory droplets containing the virus. This is predicated on air movement occurring, like on a windy day, versus a quiescent condition.

Indoors, the high ventilation rate augmented by the air filtration inside buildings can be more effective in controlling exposure because the air movement can always be controlled, meaning, there is a constant air movement present. Constant air movement = constant dispersion and dilution. Outside, there are no controls for the air movement and therefore cannot be guaranteed. Admittedly, this controlled dilution is more difficult to predict for indoor spaces such as elevators and utility rooms.

It is important to note that ventilation is not the only factor to consider in terms of avoiding infections. A number of news articles continue to mention the importance of good ventilation (high air change rates, improved filtration, etc) but they also all mention the paramount importance of being vaccinated.

Answered by Alvin Samala, Industrial Hygiene Manager, Environmental Health and Safety

Nobody knows for sure. We have seen lots of curveballs in this pandemic, and with so many variants now and different U.S. states and counties all showing different patterns from each other, it's harder than ever to predict. I do see that there is (at least) one large wave left in the emergent phase of the pandemic in the United States. What I mean by that is the current summer surge of COVID in Orange County (454 hospitalizations as of Aug. 6) will either continue to build, surpassing the summer wave of 2020 (722 hospitalizations, 7/14/2020) and look more like the wave that crested in January (although less severe) — or it will die down by, say, Labor Day. The latter would be consistent with evidence from Europe, which shows that summer surges of the delta variant are among the most evanescent of waves. There is good news and bad news here. The bad news is that if the summer wave fizzles, I expect it to be followed by a fall or fall/winter wave, much like last year. The good news is that all these waves and would-be waves will be associated with less mortality than before. The principal reason for the decrease in the death rate is vaccination, which works directly and indirectly. Directly, because vaccinated people either don't get COVID or they get mild(er) cases. Indirectly, because vaccination skews older; therefore, cases skew younger, and cases in younger people are less severe. But, in short, the COVID crisis is far from over.

Answered by Andrew Noymer, epidemiologist and associate professor of population health and disease prevention

Throughout the COVID-19 pandemic, masking has proven to be an effective tool at helping to reduce the spread of the virus. This continues to be the case, even with the emergence of the delta variant, and it’s why federal and state public health officials are now recommending that all people, regardless of vaccination status, wear masks while indoors. A recent COVID-19 outbreak on the East Coast suggests that those who are fully vaccinated and become infected with the delta variant may be able to also transmit the virus — and that is the basis for the recommendation for all to mask indoors.

Answered by David Souleles, director of UCI’s COVID-19 Response Team

Over the last 16 months, we have seen major curtailments to our daily activities and, as conditions improved, a return to many of those activities. However, as long as a large percentage of the population remains unvaccinated, COVID-19 will continue to circulate and require public health measures to help reduce the spread and keep our hospital and healthcare systems from being overwhelmed. The most important step a person can take to help get us back to normal is to be vaccinated.

Answered by David Souleles, director of UCI’s COVID-19 Response Team

Yes. Current data indicate that the COVID-19 vaccines currently authorized for emergency use are also effective against severe disease and death from variants of the virus that causes COVID-19, including the delta variant.

Answered by David Souleles, director of UCI’s COVID-19 Response Team

As long as a substantial number of people remain unvaccinated, the COVID-19 virus will continue to be transmitted between people. When the virus spreads, new variants can also emerge, as we’ve already seen. And as new variants emerge, they have the potential to be more transmissible and to cause more serious illness. That’s why, right now, the most important thing people can do to reduce the risk of new variants emerging is to get vaccinated. If the virus has nowhere to go, it will have no ability to mutate and result in new variants.

Answered by David Souleles, director of UCI’s COVID-19 Response Team

Only a small portion of fully vaccinated people get infections, even with the delta variant, according to the CDC. And these rare infections tend to be mild. However, people with weakened immune systems, including people who take immunosuppressive medications, may not be fully protected, even if vaccinated. Those people should consult with their healthcare providers about how to reduce their risk.

Answered by David Souleles, director of UCI’s COVID-19 Response Team

Recent data released by the CDC following an outbreak of COVID-19 on the East Coast suggests that vaccinated people infected with the delta variant can still spread the virus to others. Public health officials and researchers are working to learn more about this.

Answered by David Souleles, director of UCI’s COVID-19 Response Team