January 13, 2022


Hi everyone. My name is Dr. Katelyn Jetelina. I am an epidemiologist at the University of Texas Health Science Center, where my research lab and teaching reside. I am also the founder and author of a newsletter called Your Local Epidemiologist. I have been invited back again to answer some of you guys' great questions specifically, probably around Omicron, although I haven't seen the questions yet so, we'll see what is on most of your guys' minds. I thought that I would open though, with kind of giving you a state of affairs of where we've gone since I was last on. To say it lightly Omicron has really springboarded us into a hyper dry tsunami of cases. The United States right now, our seven day average, it equals about 800,000 new cases each day, which is far higher than we've ever peaked before.

As a comparison last winter, our peak was 247,000 cases. We also know we're vastly underestimating the true number of cases, just because of our testing capacity. We just don't have the capacity to test like this, to test this much transmission in the community. The amount that we are underestimating, we don't know what that is, and it'll be time until we have a better understanding of what cases we are missing and why. Thankfully though, the past couple of days, Omicron leader in the Northeast, specifically New York and Massachusetts have peaked and they have started to descent, but other regions like the South, and the West, and the Midwest continue to increase. The south particularly, is the growth leader right now. As a country, as a whole, we expect to peak in our cases in about two weeks, probably the beginning of February. But importantly, keep in mind that we're talking out case peaks, hospitalizations and deaths lag about three to four weeks. And so we expect mid to end February is when we'll peak for those more severe indicators.

Thankfully, we are continuing to see a decapitalization phenomenon in the United States and across the globe. What this means is that, while cases are exponentially or even vertically increasing right now, hospitalizations are increasing but not at the rate of cases, and this is really due to two things. One is because our immunity is working. Our vaccines are working really well and keeping people out of the hospitals and out of death beds. Second, we have more and more evidence that's showing that intrinsically, Omicron is less severe than Delta. It's importantly more severe still than the original variant, but we will take all that we can get. And so that's really helping our hospitalization numbers. And I think we're really lucky that this decapitalization phenomenon is happening. The challenge though is how transmissible this virus is, and even if it's a lower percentage of hospitalization and death, if this virus is going through 330 million people, that low percentage becomes a really big number. Unfortunately, in the past few days, we reached hospitalization at peak. Today, I think it's about 145,000 hospitalizations compared to last winter, our peak and our highest was 135,000 hospitalizations. So, things aren't really looking good right now. We are in the smack middle of this wave, and hopefully soon things will start looking better across all of our indicators. We are just at the mercy of time. So with that, I will open it up for questions.

Should we be upgrading cloth masks to N95?

Absolutely, it is time to upgrade that mask. Omicron is incredibly transmissible. I've seen estimates putting it near measles. And so it is very easy to get infected. If you're exposed to this virus. We know that N95's work really well. They block 95% of particles. And so, if you have access to an N95, I would certainly upgrade it. The next question that I always get is, what about those KN95's or KF94's? I would put those at the same level of effectiveness as N95's. They're great. And that particularly good news for us with little kids, because kids don't have N95's, they don't make it for them. And so those KN95's over those KF94's work really well. They're a bit more comfortable too, because they have loops around the ears, they have this like duck appearance, so it's a little more comfortable for people as well. So yes, upgrade.

Now, if you can't get your hands on either of those with your cloth mask, sometimes there is a pocket. So, I would certainly put a filter in that pocket if possible, or I double up, put the cloth mask with a surgical mask, and that's much better than just a cloth mask. So yes, time to upgrade those masks especially if you are indoors in public areas.

Should everyone try to have at home antigen tests and how often should we be testing?

At home antigen tests is the most underutilized tool in this pandemic. And I think everyone should have them in the home, we should all have them in our closets ready to take. If you went to a business trip, take a test, if you are going to visit great grandma, take a test. The problem is what is reality right now? And the reality is we just don't have the testing supply for what these are meant to be for breaking transmission chains. And so we have to be very smart in when we use these antigen tests and who uses those antigen tests.

So, right now during the Omicron wave, I would not be testing. If you are asymptomatic and you're not going and visiting vulnerable populations, please keep these antigen tests for those that really need them. For example, those that need to be tested for treatment like the antivirals, they need them, those that are vulnerable, need them right now, and if you're asymptomatic, you need them. So, I would be a little more guarded about your at-home antigen test supply if you are even able to get them on your hands.

How often should we be testing?

Now, if you are asymptomatic, and like I said, try not to do this, but if you're going to great grandma's, I would definitely test every other date just to make sure you're not bringing the transmission, you're not bringing the virus to that vulnerable population. Now, if you're asymptomatic, I would start testing using your antigen test about two to three days after you have symptoms. And the reason for this is because we're seeing that antigen tests are a little less sensitive with Omicron in the beginning of infection.

Omicron is so transmissible that it's taking a little longer for those antigen tests to register that you have Omicron. We're going to see a little more false negatives. And so hold onto your test, hold onto that precious test supply that you have and wait a few days after symptoms. You should definitely isolate then test a few days. And if you get a positive, you'll know. And then I would definitely retest about five to six days after symptoms. CDC says, you can go back into the public if you're asymptomatic, or if your symptoms are getting better. I, I, I don't necessarily agree with that, but that is what the current guidance is. And so I would yeah. Use those tests to determine if you're positive and then determine when you can get out of isolation.

Should we wait a certain period after contracting COVID-19 before getting the booster shot?

This is a really good question. And no, you do not need to wait. All you need to wait for is for your symptoms to be getting better. For example, not have a fever. This is usually about 10 to 14 days after your symptoms start. And really, it's because we don't want you going to CVS and infecting everyone at CVS. But, you certainly don't need to wait the 90 days like a lot of people think that they have to wait. You do have to wait the 90 days, if you are treated with monoclonal antibodies, but with this Omicron wave, monoclonal antibodies aren't really working, so we're not giving them. So, if you get infected, definitely go get your booster at minimum 14 days after symptoms.

How do the COVID 19 vaccines lessen the likelihood of transmission and prevent people from being hospitalized?

Okay, so there's two parts of this, one is transmission. Before Omicron vaccines reduce transmission about 50% to 70%.

They were actually really good at doing this. And we got really lucky. This isn't the vaccine's main priority. It's not to stop transmission. And so, with the two-dose series, we did stop transmission a lot before Omicron. With Omicron, this doesn't seem to be the case with the two-dose series. Now, if you have the booster, although we haven't seen the studies, we hypothesize that transmission is reduced a lot. That's because boosters actually really work against Omicron. Depending on how long ago you got your booster, there's about a 50% to 80% efficacy against Omicron with that booster. And so, because of the high efficacy, we do believe that transmission is reduced. I wouldn't assume that all booster people don't transmit the virus. I would assume worst case scenario that you are. But we do have reason to believe that transmission is reduced, which is fantastic news.

The second part of that question is, how are vaccines working against hospitalization and death? And they are working fantastically, even among those with no booster. It looks like the response, the secondary defense, which is our T-cells are holding up. So, it looks like vaccines and even some of those with the infection induced immunity are staying out of the hospital. And this is really great news because this is causing this decapitalization effect that I was talking about in the beginning. And we really need all the help we can get on an individual level, right? Not to show up at hospital, but also as a population level, not to overwhelm our hospital systems. And so, we're really happy with how the vaccines are holding up with severe disease.

When will we see COVID 19 vaccine approved for kids under five?

Yeah. So, I have two kids under three, and I've been very disappointed on how long this is taking, but, unfortunately, or fortunately, they're testing a lower dose.

So even lower dose among the five- to 11-year-olds, which was a lower dose than those for 12 plus. And because it's a lower dose, it doesn't look like they got that dose right in the first place. And we want to make sure it works and it's safe. And so, unfortunately Pfizer had to kind of redo their randomized control trial, and it looks like Pfizer's vaccine will be coming this summer if everything goes well. Now, Moderna's vaccine should be coming in March, at least the data for that vaccine should be coming in March. However, there's a bit of question about whether the vaccine for five and unders came and be authorized. If the Moderna vaccine for those five to 16 or five to 17 are not authorized. And I don't know how that works. And so I'm really not holding my breath for this Moderna vaccine. I truly think the first one will be Pfizer and unfortunately will probably summer of 2022. So, us parents still have a while.

What should people do if their taste and smell still hasn't returned more than a year after contracting COVID?

Yeah, so unfortunately you are not alone. About 10% of people that lose their taste and smell from their initial infection hasn't gotten it back. And I know this impacts quality of life dramatically. And so, thankfully, there are long COVID clinics that are starting to pop up all over the country. So I would certainly have a conversation with your primary care physician about what they suggest and where those long COVID treatment centers are that can particularly focus on these symptoms and are most up to date with the data and even treatment. And so, I would definitely reach out to your healthcare team and not lose hope. We are seeing that people are getting their tastes and smell over time slowly but surely. And I'm hopeful that these people will as well.

Do we know if Omicron is as likely to cause long COVID as other strains?

No, we do not know. You know, long COVID is incredibly difficult to measure and that's why we have really bad sense of long COVID because it's the range of symptoms are so different. They range from loss of smell and taste, to memory fog, to even brain matter degradation. And so it's so wide that it's really hard to understand the true prevalence, even before Omicron. The other issue is that these symptoms of long COVID are very similar to symptoms of people weren't COVID. So for example, headaches is one of the biggest or highest prevalent side effects of long COVID. But I get a headache every time my toddler screams. And it's really difficult to measure. And in the United States, we do not have a good sense of this, even before Omicron. Now, Omicron enters, right? And it's a little less severe, and that's because the virus isn't replicating as quickly in our lungs as it is in the upper respiratory.

And so, there's really two competing hypotheses here. One is long COVID going to be less severe with Omicron because there's just not that much viral load, or on the other hand, is long COVID going to be more severe because there's a whole different disease pathway that it's finding that it didn't do prior. And it's going to be a while until we have a good sense on what that is unfortunately. And I think with everything in public health, we really prepare for worst and hope for the best. And so, I think it'll be a little while until we see data on this. And so, we have to be patient and see what the mercy of time again.

If you've had COVID presumably Omicron and two subsequent negative PCR's, how long are you immune, and when are you vulnerable?

Okay, this is a good question and one of the biggest unanswered questions we have right now. We don't know how long Omicron immunity lasts. And that's really important to answer because that has major implications on when our next wave is going to be and the severity of that wave.

Again, we have two hypotheses, right? One is that, it's going to last as long as previous variants, which was about, I don't know, 16 months. But, there's the other hypothesis that, because this isn't a higher viral load, because our response isn't so intense with Omicron, that maybe immunity doesn't last as long as Delta and we simply don't know. I will say I'm pretty confident that the immunity will last for about, certainly, for 90 days, but what happens after that with the waning is certainly up for debate and we haven't seen the evidence yet. So unfortunately, we just don't know.

Does previous infection with COVID lead to herd immunity? And it sounds like prior infections do not protect against Omicron, so is herd immunity even attainable?

Yeah, so previous infection or infection induced immunity does help with our immunity role. It's a bit more random, and that's why we're really suggesting vaccines with a more uniform response, but, there is such thing as natural immunity, right? We do have that and it does help with our wall.

I think that herd immunity it's been a point of confusion throughout the entire pandemic. Herd immunity is a policy. It is a policy goal. It's not that once we reach 90% or 95%, what we need with Omicron, that everything's good, and all cases drop, and we're good to go. All of that herd immunity means is that once we get transmission down, it can stay down. And you're right, a lot of people aren't confident that we're going to reach herd immunity on a national level, even on a global level, we've only reached this twice ever. One is, with smallpox and that's because we vaccinated our way out of smallpox. And two is with measles. We reached herd immunity in the United States and in the early 2000's with measles. Unfortunately, this is not the case anymore due to the increased anti-vax movement in the United States, we are not at herd immunity for measles in the United States right now. It's certainly geographical, we’re determined, and we only know when we reach herd immunity once we've reached it. We don't know, it's a very retrospective look rather than a prospective look. And so, it's to be determined, but I'm not holding my breath that we're going to reach herd immunity with SARS-CoV-2.

What does endemic mean, and what does endemic look like for workers and employees?

So endemic is also highly misunderstood. This basically is up for interpretation, but what it means essentially is that our lives are not disrupted by SARS-CoV-2. And so, what does that mean? It means that we won't have state level crises like we're seeing right now, it means that our hospitals will not be overwhelmed, it means that we're going to have an outbreak here and an outbreak there, and hopefully it also means that we're going to start seeing this pattern of seasonality. So corona viruses thrive in the winter. It's no coincidence that our biggest two waves yet were both during the winter. And so, what I think this will start looking like is that even as soon as 2022, is that we're going to see about two mutations a year or two mutations that mean something to us a year with waves in the winter, just like we see with flu in the winter.

And I think what this means is that we need to learn to live with this virus. And there's two parts of that, right? We need to learn, we need to learn from these previous waves. We need to leverage the tools we have, like good masks, like antigen testing, We need to increase the supply of that, my goodness, we need to increase the supply of that. Thankfully, we also have antivirals the supply of that coming in fast in 2022, and ventilating spaces. I think one of the best things that employers could do right now is ventilate spaces really well, get that air flowing and get it filtered. That is one of the best protections you can do for your employees. And then the second part of learn to live, is live with it, right? This whole notion of let it rip kind of framework for SARS is not going to work. We have vulnerable pockets in our population, our immunity will win, we will have new variants and we get new variants more and more this thing transmits.

And so again, I think we will need to learn to live with it as the world is learned to with it. And we have the tools to do that, we just really need to utilize them on a national level better.

What is the mortality rate of fully vaccinated boosted individuals since Omicron has become a dominant strain? How does that compare with mortality rates of unvaccinated individuals?

Mortality is incredibly low among boosted individuals. That doesn't mean that boosted people won't die from SARS COVID 2, unfortunately, there are vulnerable people, especially those that are over the age of about 70 and especially among immunocompromised. But I saw a graph the other day that I actually included one of my posts that the vaccines have prevented about a million deaths since they were rolled out, so vaccines are doing really well and especially with Omicron. And so, I think the latest odds from the CDC was that boosted individuals are 17 times less likely to die from the virus, but those estimates were reported before Omicron. So we'll see.

I forgot the second part of that question. Oh yeah. So how does it compare against unvaccinated individuals? It's much better than unvaccinated individuals and we need to start trusting our vaccines that they are protecting and as scientists are very much on top of it to ensure when we need a next vaccine, because we probably will. The debate is out there of when that will be and what type of vaccine that will be. But for now we have a lot of confidence in them. Okay.

What happens when someone is exposed to COVID but does not get infected? How does this act as a boost in any way?

Okay. So if a vaccinated person is exposed to the virus, this means that the virus enters your nasal passage way and it floats around to try and find a cell. Now, importantly, the vaccines work really quickly and they have these or our immune system works really quickly actually and we have these things called neutralizing antibodies. These neutralizing antibodies find the virus before the virus even goes into the cell to start replicating. And that is why vaccines work really well against stopping transmission because you can't transmit a virus or a disease that you never get.

Now, sometimes we don't have enough neutralizing antibodies and that virus will infect that cell and start replicating, and replicating, and replicating, and you'll start getting symptoms and you'll be contagious. In that sense, you can be asymptomatic and have the disease and start spreading it to people. Or you can be symptomatic and start spreading it. But importantly, once that replication starts and you have symptoms and you're contagious, the vaccines still help a lot, and they help clear that virus much quicker among unvaccinated people. And so the vaccine immunity, even infection induced immunity helps in those two ways. So, we can be pretty confident in that.

And then the second pat of the question, does this act in a boost in any way? Yes. Actually this is called hybrid immunity. So having a vaccine and an infection induced immunity. So if you have the two vaccine series, for example, mRNA, and you get infected, this is basically a booster.

Now, we still recommend that you get a booster because we don't have a solid understanding from the data on what this relationship looks like and for how long, but it does help with your immune system and that immunity wall that you're building.

Do we know if it's safe to be outdoors unmasked with others given the contagiousness of Omicron?

We haven't seen any data come out about this. I suspect though that if you're unmasked outdoors, there's still a little likelihood of your infection. The thing that outdoors brings is increased ventilation. It really helps this airflow and really dissipates the cloud of SARS-CoV-2 around an infected person. And so that's why it's still a lot more safe outdoors than indoors. Now, can you get infected outdoors? You could, but the likelihood is much less than indoors. And so, honestly, when I'm outside and it's not crowded, and I'm talking, I'm not at a concert shoulder to shoulder, I'm comfortable not wearing a mask. If you're outside and you're at a shoulder to shoulder event, I would certainly wear a mask outside. There are multiple factors that play into transmission.

You talked about numerator and denominator in a recent newsletter. I did. It was this morning. How can we use that to communicate with workers about risks?

I think, how do you do it? You communicate, both angles. You communicate how important it is to recognize the numerator, how many people are in getting infected? What are those trends looking like? But you also present the other side and what that denominator looks like. I think that also employers and jobs really also need to understand I know a lot of policy makers are denominator people, but a lot of people are enumerator people too. And so we really need to understand the perspective from both angles. And we're moving into a denominator policy driven world, we have to.

And so, I would do the best to communicate the difference and go from there. We have the tools to make a workplace very safe. We have really good masks, we have antigen testing, and most importantly, we have vaccines. And so, if everyone's vaccinated or if there's some people that are unvaccinated, if they still wear a mask, a really good mask, the odds of transmission in that workplace are low, it is. And we need to get a lot more comfortable using these tools at hand and to start living smartly with this virus. And so that is the end of this. I want to end by saying yes, things are bad right now. Do not take Omicron lightly, but don't lose hope either. We have a lot of tools that are working really well. We're also incredibly lucky that Omicron is less intrinsically severe, and we are starting to see light at the end of the tunnel with this Omicron wave. So, hang in there.

If you ever have more questions, I am available on my newsletter, called Your Local Epidemiologist. I try and get a few posts out a week on the latest data. I'm also on Facebook, Twitter, and who knows? The U.S. Chamber of Commerce Foundation may invite me back for another and ask me anything. So, thank you, and happy new year, and stay safe out there.