AUSTIN, Texas — As the science and education around the COVID-19 vaccines evolve, fertility doctors still receive questions about whether or not adults who are pregnant or trying to get pregnant should get a vaccine.
Dr. Kaylen Silverberg, who leads the Texas Fertility Center, talked with KVUE'S Mike Marut about his advice.
Mike Marut: The past year, being a fertility doctor, how many questions have you gotten in regards to not just COVID and how this affects pregnancy or fertility, but now the vaccines for the past six, seven months?
Dr. Kaylen Silverberg: There's just been a nonstop barrage of questions really that have come in. So the disease comes around and people are getting sick and they're worried and they're masking and they're getting confusing, contradictory frequently information from authorities and they don't know really what the right thing is to do. And so they all come in and they ask questions or they bombard our telephones with questions. And what we tell them is what we know. And we also tell them what we don't know. OK, so let's kind of review what we know. We know that COVID is real, OK? We know that COVID can be serious and we know that COVID tends to be more serious in pregnancy, for a variety of different reasons, but it tends to be more serious in pregnancy. Therefore, even though the Centers for Disease Control and the World Health Organization went back and forth about their guidelines, the Centers for Disease Control has been pretty consistent that women who are pregnant or trying to get pregnant should get vaccinated. The World Health Organization has been much more hands-off, 'No, no, no, no, no, you shouldn't get vaccinated.' And that's really been a problem because it's really transmitted contradictory information and confusing information to a lot of people.
Mike Marut: How do you clear that up with people? I mean, not even just the discrepancy between the two organizations, but as time goes on and we learn more about, again, either COVID or the vaccines, right, clearing up what is old information versus the newest information.
Dr. Kaylen Silverberg: And this is what people need to understand. The point that you're making is a really valid point. Information evolves. You know, we learn this is a brand new disease, right? I mean, it didn't exist two years ago. And so we've had to learn a whole lot. And a lot of scientists have really put themselves through a crash course to try and learn as much as possible about this disease. The Operation Warp Speed thing was incredible: To get a vaccine delivered - from not even knowing about a disease to getting a vaccine delivered against the disease that would protect the overwhelming majority of people in 18 months is crazy. And so it's really wonderful that we were able to get that accomplished. Now there are a bunch of differences between the vaccines. You have two basic different categories of vaccines. You have the messenger RNA vaccines and you have vaccines made using the "old technology." And I'm air quoting "old" because it's not really "old technology." It doesn't mean that it's outmoded or not good anymore. It's still very good technology. But what we used to do to make vaccines is we used to take a particle from the virus. We would either heat and activate it or kill it in rare cases, use small particles that were alive and inject those into people and cause your immune system to make a reaction to make antibodies against that virus itself. And that's what the Johnson Johnson vaccine is. So it's a vaccine using the traditional, as opposed to "old," traditional technology. Moderna and Pfizer are brand new earth-shaking technology where they take messenger RNA, which codes for protein production, and what they did was they basically reverse-engineered a couple of areas on the spike protein, which is part of the protein code of the virus that allows it to attach to human cells and subsequently infect human cells. And so they manufactured the RNA against those that would produce a protein that was on those five proteins, and then they inject that messenger RNA into our bodies and that causes our bodies to make antibodies as well. And as it turns out, when you look at the data, at least so far, it looks like the majority of Pfizer vaccines are more effective. They've got broader coverage if they are conferring protection in over 95% of patients who receive it, whereas Johnson Johnson is more like the low 70%. That kind of clarifies the differences between the vaccines.
Mike Marut: Is there a technology between the messenger RNA versus the traditional vaccine delivery? Is there one that is more effective or seems to be more effective when it comes to helping not just potential mothers, but if they are pregnant, whether it's a fetus or depending on how far an embryo, how far along they are in the pregnancy?
Dr. Kaylen Silverberg: Let's talk about what we know, what we don't know as far as the virus goes, OK? All we knew a few months ago is what the virus would do to pregnancy if a woman was infected towards the end of her pregnancy. We had no knowledge about what would happen if a virus affected a woman's pregnancy in the middle or even at the beginning. We know if you look at chickenpox, if you look at herpes, if you look at viruses that we understand very well and know about, now we know that certain viruses affect the pregnancy only at certain times during the pregnancy. So chickenpox, for example, if you get infected with chickenpox early in pregnancy, probably no big deal. But if you get infected with chickenpox late in pregnancy, it's a little bit of a problem. OK, German measles, we know that's got effects, different effects at different times in the pregnancy as well. So what we're learning now is because the virus has been around for a longer period of time and now we have some women who are pregnant who got infected early in pregnancy and maybe somebody got infected in the middle of their pregnancy. They're collecting that data now to see what's going to happen. But the biggest problem with that is some illnesses and some diseases may not arise at birth. They may not present at birth. It may be that, God forbid, children get developmental delays or things start to show up three years from now, five years from now, 10 years from now. It's not likely, but it's always a possibility. And so we have to be honest with our patients and tell them what we know, what we don't know. The second question that you asked was about the technologies. So there was a report that circulated very widely on the Internet. Some guy in Germany, a scientist came up with a theory about messenger RNA and his theoretical concern was, "Hey, wait a minute, if you take this messenger RNA vaccine, you may make antibodies to placental tissue, which would render you sterile." There's absolutely no evidence that that's true in laboratory studies that have been done so far. It's flat out not correct. There are very few human trials or even ongoing looking at this. But some people are actually interested in looking at this and evaluating it further. No data has come out yet regarding the results of those trials.
Mike Marut: How far have we come just in the past year when it comes to studying this? I mean, it's been such a widespread virus. How far we come with the research?
Dr. Kaylen Silverberg: Well, so there's different types of research, and research into viruses is pretty difficult to do. And let me tell you why. If a new pharmaceutical drug comes out, we design what's called a prospective randomized placebo-controlled study. In English, what that means is we take two groups of patients, one group we give the actual drug we're studying and one group, we get the placebo and we don't tell the patient what we're giving it to or which one we're giving to them. They've consented to that. They understand that. And then we can evaluate the data downstream and find out if that drug made a difference or not. With viral infections, you can't do that, you can't say, OK, I'm going to infect this group of people with a virus and I'm not going to infect this group of people with the virus, or I'm going to give this group of people a vaccine and I'm not going to tell them, but I'm going to give this group of people a placebo vaccine. Those were done under very, very small sample sizes early on to try and determine if, in fact, the viral vaccines that they were looking at were even effective. OK, but it's hard to do long-term studies like that. So what we're doing more now is what is called a registry study. So they are following people who got infected at different points during the pregnancy. And they're following not only them and their health, but they're following the outcome of their pregnancy. So were their babies smaller than they should have been? Were they bigger than they should have been? Do they have a greater likelihood of being admitted to the intensive care unit or not? Do they have any evidence of getting infections or diseases in the first year of life? And they'll follow these kids longitudinally and it'll take years for us to really know and have that data analyzed and know what it shows.
Mike Marut: Have you faced any challenge with having to convince people one way or another throughout the past year?
Dr. Kaylen Silverberg: Absolutely. No one knows the right answer. Anybody who tells you that they know the exact right answer with a disease that's only been known to mankind for 18 months is fooling you. They don't know. We just don't know. We have no idea what the long-term effects are going to be, if any. We have no idea if booster doses of the vaccine are going to be needed, if any. You know, I mean, think about vaccines that we know already, right? I mean, we know the flu shot you have to get every year. With a tetanus vaccine, you get a booster every 10 years. A German measles vaccine, you get it once when you're a kid, and never again. So the fact that we don't yet know with a virus that's been around for 18 months, what the ultimate treatment course is going to look like is expected, is not a surprise. It's not that people aren't doing their research and they're not doing their work. There's just no way for anybody to be able to predict the future, but it looks highly unlikely that there are going to be down the road problems. But again, nobody knows the answer to that question. We just don't know.
Mike Marut: The studies that have been done recently in regards to the vaccine suggest that there are no harmful effects from the vaccine on fertility. Are these studies that you have looked at specifically as well, or is this something that is still so new that you are waiting for even more to come out before talking about that with patients?
Dr. Kaylen Silverberg: The studies that have come out are preliminary, right. Let's look at male fertility, for example. There are studies that come out that have suggested that there's no change in sperm count due to the vaccine. There's a couple of small studies that have suggested that there is a change in sperm count. But what these studies don't take into account is it takes between 90 and 108 days from the time that sperm cell starts to develop in a man's body until it comes out. So any time during that 90 to 108 day period, if a man gets infected, gets a fever, gets some other problem, you can still see an effect. So we're going to need long-term studies to be able to determine, number one, is there an effect on sperm count? And number two, is it long-lasting? And number three, to the sperm counts, if there is an effect, do they recover?
Mike Marut: And one of the studies that I sent over to you and actually prompted this interview in the first place, said that they only tested like 45 men or something like that. Is that research like that? I'm not going to say that it's not helpful because we need as much as we can get right now, but 45 men is not a big population to be testing at all.
Dr. Kaylen Silverberg: Correct. Any study that reports on forty-five people, you've got to take with a grain of salt. Because we're going to have thousands, tens of thousands, maybe hundreds of thousands of people that are eventually going to be studied and eventually reported upon, and all forty-five will do is scare people. You know, it may be that you maybe you've got a small study that's reassuring that the numbers are so small you can't know with certainty that that's really reassuring. It just and conversely, if the study is only involving forty-five people, and it suggests that five people have a problem, you don't know if that's going to be real or how that's going to be borne out when larger numbers come out.
Mike Marut: Having all the research that we do right now, what do you tell patients, what do you tell couples that come to you and say, "Hey, we're thinking about getting pregnant or we're trying to get pregnant, but we have not been vaccinated yet?"
Dr. Kaylen Silverberg: What I tell people is they've got to make their own decision. We don't have all of the answers, any doubts that they have are reasonable because again, we don't have all the answers. But what I tell them is based on the best available evidence that we have on July 2, 2021, they should get vaccinated. If they're pregnant, they should get vaccinated. If they're trying to get pregnant, they should get vaccinated. I strongly believe they should get vaccinated. I got vaccinated. So, I mean, I tell people and I can't I can influence what they think, but I can't order them to get vaccinated, they need to do what they think is right.
Mike Marut: Those are the only questions I have for you. Is there anything else that you want to add about the research that's been done so far in regards to the vaccine and fertility? Or is there anything that I missed? Anything important to talk about?
Dr. Kaylen Silverberg: No, I mean, there's a lot of stuff. I hate to say it over and over again. But there are just so many things that we still have yet to learn. But what I want to emphasize is that I would encourage people to do their own research, but I would also encourage them to speak to medical professionals and get that research validated because there's so much misinformation coming out of the media, so much misinformation coming out on the Internet. And it's very important that people know how to assess scientific studies. The average person can't really assess a scientific study. They can read it, they can read the conclusions, they can understand it. But they don't know if that study is scientifically valid or not. They don't know if there's a bias introduced or if there's no bias or if it's been limited. And so a lot of scientific studies that come out, especially in a topic this important, I would encourage people to go to your physician and talk to your physician and ask questions. If you have any doubt about what you should do, ask and doctors will tell you to the best of their knowledge where we are today. But unfortunately, things have a way of changing over a period of years. And we don't know the long-term effect of either the viral infection or of the vaccine.
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