Polio's threat can be easily overcome by readily available vaccine
Host Amber Smith: Upstate Medical University in Syracuse, New York invites you to be "The Informed Patient" with the podcast that features experts from Central New York's only academic medical center. I'm your host, Amber Smith. Dr. Leonard Weiner is the senior member of the pediatric infectious disease team at Upstate. And while his colleagues have been taught to care for someone with polio, Dr. Weiner is the only one who can tell stories about actually taking care of patients with polio in the early years of his career, when it was much more common. Dr. Weiner is a professor of pediatrics and pathology, and he specializes in pediatric infectious disease. Welcome back to "The Informed Patient," Dr. Weiner.
Leonard Weiner, MD: Glad to be here.
Host Amber Smith: Did you ever think polio would make a comeback in America?
Leonard Weiner, MD: Well, I hate to use the term "comeback," but it's not totally surprising that we do see cases pop up, including the most recent case that's, garnered so much attention in the press. and in New York state.
Polio still occurs around the world, and it has been imported into the United States from time to time. And this unfortunate patient in Rockland County is not the first time. I took care of a patient with polio from what's called a vaccine-derived strain in the year 2000.
And as I mentioned, there have been cases, around the country, in subsequent years. The important thing to remember is that those cases occur in under-immunized communities. They would not occur in a community where the immunization rate is at a level which is effective in preventing polio.
Polio vaccine, given in its full course, is 99-plus percent effective in preventing polio.
Host Amber Smith: So, we've seen sporadic cases here and there in the United States in the recent past. But this seems a little bit different with the governor declaring a public health emergency. It seems like people are getting really worried about this.
Leonard Weiner, MD: Well, I think they should be worried about it, but again, it represents the difficulty of controlling what is normally fully vaccine-preventable disease when you have low rates of vaccination. The counties in question downstate, particularly Rockland County and Orange County, have some of the lowest rates of polio immunization in the United States.
Host Amber Smith: So, when did you start practicing medicine? And what can you tell us about the patients that you took care of with polio way back then?
Leonard Weiner, MD: Well, I've been at this a long time, but let me just give you some background. The last wild case, when I say "wild" polio, I'm talking about a virus that is not derived from a vaccine. And I guess that requires some clarification.
The vaccine (used in) the United States now is inactivated vaccine. It has no potential whatsoever of causing disease in anybody, but it is, as I mentioned, almost a hundred percent protective when administered properly. Oral polio vaccine, the so-called Sabin vaccine, which has not been used in the United States since the year 2000 or so, but is used in other parts of the world, has the potential since it's live and it replicates, that means it grows in people to produce the protection. Rarely, that virus reverts back to a disease-causing strain. That reversion is usually in the so-called Type 2, which is what's happened in this particular case. And it's happened before and does happen in other parts of the world as well.
So with that background, what we have is a scenario where somebody comes in contact with somebody who had oral polio vaccine somewhere other than in the U.S. and picks up the virus and either gets sick directly because the virus is the so-called reverted virus, or it passes through people. It's infectious from one person to the next.
And by the way, that's why oral polio is used in other parts of the world, because it does spread and protect. In the United States, we don't need that, but in other parts of the world we do, because we don't reach out with the vaccine to everybody. So it's kind of a yin and yang; we have a great vaccine for all scenarios, but occasionally the Type 2 strain in the oral polio vaccine can revert and cause real disease.
And that's what happened here somehow. And nobody knows for sure how yet. This person who developed it was an adult who developed polio, paralytic polio, was exposed to somebody who got oral polio outside of the U.S. or brought it back, and that strain has caused disease. And that's what people are identifying in wastewater and in specimens from other individuals. And that's why the governor, I think appropriately, has said we've got to get this under control. This is an emergency.
Host Amber Smith: There are stories of parents in the 1940s that were afraid to let their kids play with other children or go where there might be crowds -- movie theaters or swimming pools. What do you recall about the mood of the country at that time?
Leonard Weiner, MD: So, I recall not in the '40s because it's before my time, but I do recall my, parents not letting me go to the community pool because they were afraid of polio. So the last major outbreak in the U.S. was in 1952, there were 20,000 cases of paralytic polio that year, the highest number ever, and, by 1955 with the use of the inactivated vaccine, the killed vaccine, so-called Salk vaccine, polio was pretty much quickly eradicated in anyone, in any community where vaccine, was utilized.
And that's the scenario of where schools and clinics were set up, and everybody went and got their shot, and then they would get the remaining shots. Polio vaccine requires four doses in children, at 2 months, 4 months, 6 to 18 months and then another last dose at between 4 to 8 years of age. If you do that, you never need anything else later in life, and you're protected against polio.
Host Amber Smith: So is the polio vaccine in use today the same one from back in the 1950s?
Leonard Weiner, MD: How should we say this? It's been spoofed up, it's better than it was then. It's been modified. But in the early '60s, we went to the so-called Sabin vaccine, I mentioned that before, which was the live vaccine. And we used that in the U.S. through 2000. And then in 2000, it became clear that the complications of that vaccine, the rare, less than one in a million chance of getting actual polio from that vaccine was still greater than the risk of going back to the newer inactivated vaccine that we use now. And so, since approximately 2000, we've used only inactivated, but it's a newer inactivated, and it's more effective.
Host Amber Smith: When it was first made available, was it just for children, or was it for everyone? Did the whole population need to get vaccinated at first?
Leonard Weiner, MD: No, because most polio occurs in children, and we can go into that quickly. That's because, as I said, most people who get polio have no other symptoms other than maybe flu-like or nothing, and yet they're protected. So, in the 50s and 40s, most adults who didn't get sick already had some protection. So this was a childhood vaccine.
Host Amber Smith: Were people receptive to getting vaccinated, or was there skepticism when it first rolled out?
Leonard Weiner, MD: Again, I wasn't there, but I can tell you from the pictures that they lined up for blocks and blocks, and then when it became, in the early '60s, the live vaccine on the sugar cube, schools were doing it every day until everyone was fully vaccinated. This was a very, very safe vaccine, even safer today, and highly, highly effective. And if you've been fully vaccinated as a child, you do not ever need a booster -- unless you maybe are going to parts of the world as a health care provider where polio is still seen.
Host Amber Smith: This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith. I'm speaking with Dr. Leonard Weiner, a pediatric infectious disease specialist and professor of pathology at Upstate. And our subject today is polio.With the polio virus being discovered in the wastewater in New York city and a case of the adult being paralyzed by a polio infection, how big of a threat is this disease to the general population?
Leonard Weiner, MD: Well, that's the key question, isn't it? And I would just point out what we touched on earlier, which is that in the scenario that we're seeing now, it's only a threat for communities where vaccination rates are low. If you were vaccinated as a child, it doesn't matter that it's in the wastewater, or somebody else might potentially transmit it to you. It's not a threat to you. However, if you're talking about communities with low vaccination rates, then the virus is able to spread and cause disease. So the answer, clearly, is we have an effective and safe vaccine, very effective, very safe. We just need to get it out there.
And, as a marker of what can be done, back a few weeks ago in Rockland County, they administered 2,000 doses of polio vaccine in one afternoon.
Host Amber Smith: Just from people who suddenly recognized the importance?
Leonard Weiner, MD: They recognized they were under vaccinated and they showed up.
Host Amber Smith: Now, if someone was vaccinated as a child, as an infant, or if they can't remember whether they were vaccinated or not, is it worthwhile to get a booster at this point?
Leonard Weiner, MD: Since the '70s in the United States, it's been a school requirement to be fully vaccinated against polio. So if you went to school -- not home school, but if you went to a public school -- to be vaccinated. If anybody has any question, since records going back that far are hard to find it's perfectly safe to get polio vaccine additional doses. However, it's usually not recommended even in the scenario we're talking about for adults because they were adequately vaccinated as youngsters.
Host Amber Smith: We've heard about viruses that mutate, such as with COVID, the SARS CoV-2 virus, so I wonder if that could happen with polio. Is the disease that we're seeing today the same as it was in the 40s, or has it changed?
Leonard Weiner, MD: I'm going to answer that in two ways. The virus that is derived from the vaccine -- which is what we're seeing now, and what's in the wastewater and what caused disease in Rockland County, in Israel and other parts of Europe -- that is a mutated virus from the oral polio vaccine strain type 2. So it is a mutation. I commented earlier, this was sort of a reversion back to a disease causing virus from the attenuated form that's usually in the oral vaccine.
However, the second part of your question really relates to, if you get polio nowwith one of these mutated strains, is it really any different than what polio used to be? Or if you're unlucky enough to be in Afghanistan and you get polio, is that a different disease now? And the answer is no. The disease is the same, and in some cases tragically the same, but we're not dealing with the same kind of mutation that we associate with, for example, COVID or even influenza virus each year, when we have to change the vaccine to match the virus, because it changes each year.
Host Amber Smith: So let's go over, if you don't mind, what are the symptoms, and how is this diagnosed today?
Leonard Weiner, MD: Again, the most important thing to remember is that most individuals with polio, and most of them are children, almost all are children,will have little or no symptoms. If they have symptoms, about one in four or one in five, of those that are infected -- the others being truly asymptomatic -- the one in four or one in five have a little low grade fever, may have some headache, could start with the runny nose and end up with a little bit of diarrheal illness, loss of appetite. And the incubation for period for that from one person to the next is somewhere around three to six days.
So it gets transmitted pretty quickly by the fecal-oral route. If you're going to develop paralysis --and, as I said, that's quite rare -- somebody who's infected may be one in 100 or even less than that. Around seven to 21 days, you begin to show signs of, usually, upper arm or upper leg weakness, and that can progress over the next days and can be severe, and in a small percentage affect the breathing muscles. And those are the individuals who are at greatest risk and have to go on a respirator, and sometimes, in the past, those people did not survive. And in other parts of the world, they don't survive.
Host Amber Smith: Since this mainly affects children, if you're an adult here in New York and you were not vaccinated as a child, is there a reason to be,or not?
Leonard Weiner, MD: Oh, absolutely. I mean, I think that's partly what the health department and the governor is trying to get people to do, if you were not vaccinated as an adult. Remember the case that alerted us to all this was an adult. That was not a child. The individual in Rockland County was an adult who was not vaccinated. It was part of a community with a very low vaccination rate, and that individual, even though we don't know who that is, we do know that that individual was not vaccinated. So if you're not vaccinated, or you think you're not vaccinated, that's a real trigger to go get vaccinated.
Host Amber Smith: Can you tell me about how the disease is treated today and compare it with how it was treated when you were coming up?
Leonard Weiner, MD: So, there is no antiviral agent or the class of viruses that polio... so polio is an enterovirus. There are other enteroviruses that cause a wide range of disease from just minimal illness. There are even some that can cause a polio-like illness called acute flaccid myelitis. And we do see that from time to time. So that quite closely mimics polio, though it's not the same strain. It's a cousin, so to speak. It's part of the enterovirus family. We do not have drugs that can inactivate the enterovirus group of viruses.
So polio treatment and treatment for the other paralytic diseases that come from the other types of enteroviruses is always supportive treatment. And it was supportive treatment back in the 50s and before. And the main support in those days was, if you had trouble breathing, was the iron lung, and we don't do that anymore. We use respirators. But it's supportive treatment. There is no magic medicine. And, that's why vaccination is so important, because you have to prevent. The real point to remember is that we do have an almost 100% perfect prevention for this disease, and that is polio vaccination, which is one of the safest and longest standing vaccines. Remember, we're talking about Jonas Salk, who discovered the inactivated vaccine and first gave it to patients in the early 50s. By 1955, even though 1952 was the year with the largest paralytic polio outbreak -- 20,000 cases -- by 1955, that number was down to hundreds, just due to vaccinating children in schools and at houses of worship and community centers. It was miraculous..
Host Amber Smith: And since then, pediatrician's offices have been giving out the vaccine to the children. If you're an adult, would you be able to get the vaccine from your primary care provider?
Some, and also from the health departments. County health departments are now, as part of the emergency, are now being geared up to help give the polio vaccine. And, you can look online at the New York State Department of Health site, and you can see what the polio vaccine rate for children is in the various counties. And if you're in a county with a low rate -- remember, this disease is spread usually by children to other children, but also, potentially, to adults, as occurred in Rockland County -- then if you're in a community at risk or you know you are in a population group that has a low rate, you want to seek out vaccine.
Host Amber Smith: Well, I appreciate you making time for this interview, Dr. Weiner.
My pleasure. My guest has been Dr. Leonard Weiner, a professor of pediatrics and pathology at Upstate who specializes in pediatric infectious disease. "The Informed Patient" is a podcast covering health, science and medicine brought to you by Upstate Medical University in Syracuse, New York, and produced by Jim Howe. Find our archive of previous episodes at Upstate.edu/informed. This is your host, Amber Smith, thanking you for listening.