Vaccinations have been one of the greatest public health achievements of the twentieth century, credited with extending global life expectancy, reducing premature mortality and morbidity, and reducing healthcare costs. May 8, 2020, marked the 40th anniversary of smallpox eradication - recent proof that vaccines have prevented millions of deaths each year since its invention. This heralded success of vaccines can often mean it is a victim of its own success as more people decide against immunizing their children. The Public Health Insight Team discusses how vaccine hesitancy poses a threat to public health and the potential re-emergence of previously controlled vaccine-preventable diseases.
Follow us on Instagram, Twitter, and Facebook. We would love it if you shared your thoughts with us through direct message on your social media platform of choice or by emailing us at ThePublicHealthInsight@gmail.com.
Icon made by Smashicons from www.flaticon.com
Vaccinations have been one of the greatest public health achievements of the twentieth century, credited with extending global life expectancy, reducing premature mortality and morbidity, and reducing healthcare costs. May 8, 2020, marked the 40th anniversary of smallpox eradication - recent proof that vaccines have prevented millions of deaths each year since its invention. This heralded success of vaccines can often mean it is a victim of its own success as more people decide against immunizing their children. The Public Health Insight Team discusses how vaccine hesitancy poses a threat to public health and the potential re-emergence of previously controlled vaccine-preventable diseases.
Follow us on Instagram, Twitter, and Facebook. We would love it if you shared your thoughts with us through direct message on your social media platform of choice or by emailing us at ThePublicHealthInsight@gmail.com.
Icon made by Smashicons from www.flaticon.com
[00:00:00] Sully: Public health as a population-based field of science focused on preventing disease and promoting health every week, you will be engaging in interactive discussions and analyses of the latest public health issues affecting you and your community all around the world. This is the public health insight podcast.
[00:00:25] Gordon: My name is Gordon, and I'm here with our public health panel, Ben, Leshawn, Sully, and Will.
[00:00:31] Ben: Before we move on is important to note that the views expressed in this podcast are our own and do not represent any of the organizations we work for, or affiliated with.
[00:00:40] Gordon: May 8th, 2020 marks the 40th anniversary of the smallpox eradication.
[00:00:45] However, this historical achievement has been tempered as there's growing concerns that the global societal disruptions and lockdowns have been affecting the immunization rates in both developing and developed countries. In an article titled Arisun deaths from preventable [00:01:00] diseases must not be part of COVID-19 legacy, Dr. Edward Parker, a research fellow at the vaccine center at the London school of hygiene and tropical medicine, warns that the incidence of vaccine preventable diseases will spike if immunization programs are suspended. In this episode we'll discuss the emerging global threat of vaccine hesitancy and public health's role in understanding the growing anti-vaccine sentiment.
[00:01:25] So last week, the last week of April was world immunization week and immunizations as you know have been widely recognized as one of the greatest public health achievements of the 20th century credited with extended global life expectancy, reducing premature mortality and reducing healthcare costs. So what are vaccines and how do they work?
[00:01:47] Sully: So a vaccine is basically a safe way to introduce a micro organism, like a bacteria virus, or any other like pathogen into your body without the potential for an active infection or disease taking place. So you pretty [00:02:00] much insert a non-active component of the virus or bacteria. Your body creates an immune response to it.
[00:02:06] And then while that is happening, you're building up an immunity to it. So if you're ever exposed to that pathogen again, in the future, your body's already ready for it with its own immunity.
[00:02:14] Leshawn: And at the immunological level, at least we have specialized white cells called B cells or B lymphocytes, which generate these proteins that you may have heard of called antibodies or immunoglobulins.
[00:02:27] And what these do are they actually attack specific components or it's a fancy way to say it is called antigen.
[00:02:33] Gordon: Yeah. And the key component with a vaccination is that the version of the virus or bacterial or pathogen that is being introduced intentionally into the body is almost a downgraded, non-virulent strain, and what I mean by non-virulent is it doesn't have all the viral and bacterial components to cause the. Actual disease once it's introduced to the human body. So there's a lot of misconceptions that when [00:03:00] someone is admitted being administered a vaccine that you're literally taking the known virus in its active form and putting it in someone's body.
[00:03:08] So what the immune system does, immune system targets specific components of a virus or bacteria in the immune response to prevent the spread and replication of this pathogen. So in a vaccine would merely take a certain, as Leshawn mentioned, a certain portion of this virus or our bacteria, and introduce it into the body in such a way that it is recognized and the body can form its own natural response to it.
[00:03:37] So people think vaccinations is not a natural thing, but you're using an already existing immune system in the body to recognize a virus so that when it's introduced to you. You don't get sick.
[00:03:49] Leshawn: And from a historical perspective in 1796, Edward Jenner actually carried out a famous experiment. So what he did was he inserted pus taken from cowpox [00:04:00] pustules.
[00:04:00] He inserted it into an incision on a boy's arm. He saw that milkmaids often suffered mild disease of cowpox and never contracted smallpox and Jenner subsequently showed that if you had been inoculated with cowpox, you were then immune to.
[00:04:17] Gordon: And then, so this is how vaccines got its name from the smallpox vaccine. I think the Latin word or Latin phrase for smallpox vaccine is virus vaccinia. So vacca means cows. So that's how vaccines got their name. So we've talked about vaccines and how they're developed and the idea is that vaccines are given to prevent what we would call a vaccine preventable disease or VPDs, which are just simply diseases for which there is an effective vaccines available.
[00:04:50] So what are some of these common vaccine preventable diseases?
[00:04:54] Wil: I know one is called measles. I think everyone has heard of measles, it's a particularly highly [00:05:00] infectious virus caused by the measles virus, and pretty much it means that one person may directly spread to as many as 18 people, and think that's one of the notable attributes of this disease is that the frequency at which it spreads and how quickly it can spread to other populations
[00:05:18] Gordon: And for a comparitor coronaviruses and influenza are somewhere between two and five. So this is essentially three times, even four times more infectious than a lot of common infectious diseases. And another point about measles is typically given in the measles mumps, rubella vaccine to children in two doses before the age of six. And this as we'll discuss later has led to the unfounded observation that MMR vaccines are linked to autism.
[00:05:51] So given what we've talked about, vaccine preventable diseases, why are these vaccines then important on a population level?
[00:05:59] Sully: Yeah. [00:06:00] Say for example, you have a community and one person from that community travels to another community, somewhere else where they're experiencing a disease outbreak, and then they come back to that community and then they spread it in their own community.
[00:06:15] And then if you don't account for that, you're going to have a cycle of outbreaks. So what a vaccine does is it breaks that chain. It makes one community more immune to a virus so that when people travel around, they don't get affected and they don't help spread the virus.
[00:06:33] Gordon: And this goes back to the central dogma of immunology.
[00:06:36] The way it works is a human being gets exposed to a particular pathogen, and then they get sick on the first exposure. Their body usually is able to develop a response to the pathogen and have circulating antibodies as Leshawn described to attack this invading pathogen on the second time, it re-infected the person.
[00:06:56] So if do you have, as Sully mentioned, if you have a population [00:07:00] where a particular virus, it could even be an old disease like measles or even polio, for example. Our population has never been exposed to the virus from, just from an outbreak or they've never been given the vaccine, this new virus, COVID-19 when you have a new virus that comes into a population for which no one has a residual immunity, it can lead to large outbreaks.
[00:07:24] So with this let's discuss some of the kind of historical achievements of vaccines.
[00:07:30] Leshawn: I started at the beginning talking about smallpox and maybe I'll just continue a bit more about it. So smallpox actually killed 2 million people per year up until 1960s. And it was actually an immunization campaign that was actually credited with reducing the 2 million deaths per year to zero.
[00:07:49] So you can see that eradicating smallpox as a disease had a lot of public health significance because it prevented so many deaths.
[00:07:58] Ben: Polio is also such a success [00:08:00] story because we had 300,000 cases annually from the 1980s. And that fell to just 2000 in 2002. And then we also had the creation of the oral polio vaccine, which effectively eradicated two strains of polio, reducing the rates of infection by 99%.
[00:08:14] So that's a huge accomplishment in the field of vaccines.
[00:08:17] Wil: Lastly, measles. So measles used to kill around half a million people per year in the pre vaccine era, and recently it's seen in 99% decrease in the post vaccine era and has cut death rates to less than 1000 per year. And I just want to share an interesting fact with you guys. So the Pan-American health organization PAHO, which was created in 19. It is the regional office for the world health organization for the region of the Americas, and in a lot of the work we do at the agency, it's collaborating and working with PAHO on different projects. And one of their, I guess PAHO's main achievements is that under the current leadership of the PAHO director, America's as a whole was a first [00:09:00] WHO region to actually eliminate endemic transmission of measles, rubella, and congenital rubella syndrome, which is a pretty cool milestone to hit for sure.
[00:09:10] Gordon: And we'll later, we'll talk about why the theme of this episode is the paradox of vaccinations. The more successful they are, the less people will decide to vaccinate their children. So that's one of the challenges with successful public health interventions. So we talked about a bunch of different vaccine preventable diseases, and there's something called herd immunity.
[00:09:32] Which is essentially the percentage or threshold of a population that needs to be immunized to prevent a widespread outbreak. And depending on how infectious a disease is like measles as a most rapidly spreading infectious disease herd immunity percentages need to be higher. And the key thing to know about herd immunity is be below a certain threshold.
[00:09:58] The [00:10:00] population level effect of vaccinations doesn't work as well. So if you have a population where 50% of the population is immunized, then this will not curb any potential outbreaks because the sufficient number of people aren't protected. And when you have less people vaccinated, there's more people that are able to carry the infectious virus and spread it to us.
[00:10:24] Leshawn: So with that herd immunity, it's especially. Because a lot of people that may be immunocompromised or pregnant women or newborns, they're not able to get the vaccine. So to especially important that the rest of the population rally together and ensure they're vaccinated to make sure that they stay safe.
[00:10:42] Gordon: And that's another counterintuitive part of vaccines. It's actually the more healthy you are and the more able you are to tolerate getting vaccinated is more of the reason to do it because there are people who are sick and vulnerable who have underlying medical conditions that prevent them [00:11:00] from being vaccinated.
[00:11:01] So it's almost like the more healthy you are. It's the better choice to become vaccinated because you also then protect people around you. Oftentimes people worry about I'm healthy, I'm strong. I don't want to get the flu shot because I'll overcome it anyway. But you getting vaccinated against the flu, for example, will prevent you from then spreading it to someone who could then get sick and die.
[00:11:25] And I think it's a very complex message and I don't think public health has fully grasped how to communicate that to the general public.
[00:11:34] Wil: Another aspect of this is Leshawn pointed as accessibility. Like we have vulnerable populations that just can't get the vaccine, and one of the milestones of public health is that originally when vaccines were first created, for example, for the smallpox vaccine, there were huge lines of people.
[00:11:50] Lining up as akin to what we would say for like a black Friday sale, right? The line just goes all around the store. They're waiting for their vaccine, et cetera, et cetera. Now we've made [00:12:00] vaccines more accessible in the sense of you can get at a pharmacy, you can get it in schools, you can get it in different healthcare settings other than going to a clinic.
[00:12:07] So I think that's an important thing to note in helping us achieve this hurdle immunity.
[00:12:12] Sully: So we've seen, and we've heard about all the positives and how vaccines. So great and have saved the lives of millions of people each year for the last couple of centuries, since they were discovered, or people started to do research on vaccines, given all this wealth of information and scientific backing, showing that vaccines work.
[00:12:35] Why do you guys think it's still a very taboo topic in many circles? I'm sure we've all heard them. People who are very much against vaccines and the anti-vax movement and things like that. Yeah. What are some reasons that this idea is still persisting?
[00:12:50] Gordon: Something new I've learned doing research on this topic is that the anti-vaccine movement is not a new phenomenon, right?
[00:12:59] I thought [00:13:00] of it as, oh, there's something that came out in the last 15 years, 20 years about something linking to autism. And then that's when people started to distress. Vaccines is from back in the first day where Edward Jenner's was taking stuff out of the pus of cows and inoculating people, and that people were already critical of those methods and had concerns about why they were safe.
[00:13:22] So the anti-vaccine ideology is something basically where the intersection of science and reality, it's just seemed a little far-fetched for some people to believe that you're introducing a novel thing to a human being's body and the safety implications of that. And I think that's something- it's a perpetual battle we've been fighting for over the last a hundred years.
[00:13:41] Ben: Yeah. That's a very good point, especially, I'm going back to what you said about Edward Jenner's first discovery. I think if we all think back to what he did with extracting the up the pus out of them, these cowpox, and putting into a human. Just think about the societal reaction to that.
[00:13:59] If, [00:14:00] for example, I think even now if we heard something like. It's still not the most accepted by all circles. It's, there's some level of ethical consideration there, right? Straight up testing on human and individuals. Yeah. That's a good point that intersection between science and.
[00:14:18] Leshawn: Yeah. And I think if we even talk about the vaccine hesitancy cycle, I know that Gordon alluded to it earlier, but let me quickly describe how that looks. So initially you have your campaigns encouraging and promoting vaccination, which leads to an increased vaccine uptake. And then eventually you'll hopefully have herd immunity achieved and maintained.
[00:14:41] And then as a result of that, you will have a decreased incidence of your vaccine preventable diseases. Which will also lead to decreased fear, but then all of a sudden people presume that vaccines aren't important and that the conditions that have been established, they may take it for granted as a result of that.
[00:14:59] You start [00:15:00] getting increased concern and fear regarding vaccine safety, and that ultimately leads to increased reluctance or refusal to vaccinate, which is our vaccine hesitancy. And that leads to decreased vaccine uptake, which leads to. The re-emergence of a lot of the vaccine preventable diseases that we see.
[00:15:18] And then again, you start the cycle with needing to improve uptaking coverage by starting up some of these vaccine campaigns again.
[00:15:25] Gordon: Yeah. So in the most recent example of this and potent example was a series of studies that were conducted by Andrew Wakefield, formerly a doctor, and he's since lost his license.
[00:15:38] Basically there was a series of studies that fabricated how vaccines were linked to a higher incidence of autism based on certain chemicals or compounds that were administered in the vaccine. It was later shown that these individual components and MMR vaccines itself were not connected to any increase in the [00:16:00] diagnosis of autism.
[00:16:00] And we've learned in our master public health program, that celebrities are very powerful in the spread of misinformation and disinformation. Most notably Jenny McCarthy, given that she herself has the emotional connection of being a mother to an autistic child. So given that it's been disproven over and over again, That vaccines are not linked with autism in the scientific community, knowing this fact why are there still reasons why people choose not to vaccinate them?
[00:16:32] Leshawn: That brings a good point. And I think we all just have to remember that certain groups of people may have different agendas that they want to push. So even going back to our misinformation episode, people will mix a bit of the truth and then falsify the rest of their message to have some authority on a topic.
[00:16:51] But in a case like this, we just have to make sure that we're aware of where the sources are coming from. And if they are sources. Perhaps a [00:17:00] study that was fabricated and later withdrawn from a journal. We as consumers of information, have to be aware of that.
[00:17:07] Wil: For me, one of the reasons why people may choose not to get vaccinated or have their children vaccinated.
[00:17:14] Simply that the distrust for the science, even with all the research that's published for the general public, who don't have that comprehensive understanding of how these studies are conducted or just the detailed epidemiology involved in the process, it's this all just seems to be blabber. And if you don't, if, and if you don't understand.
[00:17:34] Let's say how the vaccine is developed, it doesn't matter what kind of results are shown to you. I feel that there would be some degree of distrust just simply because you don't understand it and therefore I don't want to pursue it further.
[00:17:47] Ben: Yeah. I think that's a failure of academia, Will, because there's a lot of times where we have published results, but it's not palpable to the general public because it's not being presented in a way that most people can [00:18:00] understand.
[00:18:00] So I think yes, the hesitancy and the mistrust in the healthcare system, but also the lack of trying to meet halfway with academia or more measures should be done in that sense to make sure that people actually understand what a vaccine is versus I just don't trust scientific articles in general.
[00:18:17] Gordon: So I wanted to touch on something Leshawn said earlier and Ben and Will alluded to it as well.
[00:18:24] Part of the misinformation, disinformation of vaccines, not only comes from people who don't have any credibility to speak on the matter people who are licensed medical doctors are also contributing to misinformation. So when we say to people, listen to your doctor, they are listening to their doctors.
[00:18:41] There's some doctors out there. And hopefully, they've had to answer to their licensing bodies for certain information or giving out, but are some doctors. As we discussed Dr. Wakefield, he was perpetuating the message that vaccines were harmful and they could potentially cause autism and other adverse reactions and diseases.
[00:18:59] So it's a [00:19:00] failing also of healthcare providers as well as a community and not maybe given that vaccines are not as, or vaccine preventable diseases in developing countries are not as, visible as they once were. Maybe doctors aren't even having those conversations with their patients anymore about the importance of vaccines and helping to combat the spread of misinformation.
[00:19:20] So public health's role and the role of the medical community is not to criticize or place blame, but rather to understand why they're low vaccinations and immunization rates in some population.
[00:19:33] Leshawn: That's actually a really interesting point that you bring up. I know that in the Ukraine, which actually has mandatory vaccinations in place. A lot of the patients that are vaccine hesitant, they're actually paying off their doctors and the doctors are signing notes that are saying that they have received the vaccination when in fact they didn't.
[00:19:53] Gordon: Wow.
[00:19:53] Sully: So it seems like this whole issue stems from fear of the unknown and [00:20:00] the only thing that can combat that is proper education about how vaccines work and the benefits.
[00:20:06] So wouldn't you say that in order to break the cycle of vaccine hesitancy, which was the reality for decades, wouldn't you say that education can actually break that cycle?
[00:20:18] Ben: So we wanted to find what vaccine hesitancy is first and defined by the WHO it is, the reluctance or refusal to vaccinate, despite the availability of vaccine.
[00:20:28] And the key operating term here is the definition of reluctance. So in order to tackle this issue of reluctance, we have to have a multi-pronged approach that goes beyond education. Like education still should still included, but we should also take into account legislative laws that we can pass. So for example, in Ontario, we have the immunization of school pupils act, which states that children must be vaccinated against certain diseases in order to attend school or daycare, unless they have a valid exemption.
[00:20:54] We also have the federal food and drug act, which oversees the regulation of vaccines. We have surveillance [00:21:00] Ontario and Canada has numerous iterations of infectious disease tracking since the end of the 19th century. Canada, currently has Countrywide tracking that has done under the Canadian immunization monitoring program and Ontario has central immunization information databases to track vaccinations in children. So you have surveillance, you have laws, you have education. It goes a long way in order to address this reluctance.
[00:21:24] Gordon: If we're going to create campaigns to combat the spread of misinformation and to increase immunization rates and to let populations know how important vaccinations are. Then we have to look at some of the contributors to vaccine hesitancy. So one of the most common contributors for why parents decide not to vaccinate their children is actually because of philosophical and religious reasons. And we know that these are very deeply held beliefs by a lot of cultures and communities and it's not [00:22:00] something you can simply ask them to overlook. We have to work with these communities and find out what information would be helpful in helping them to make the most healthy decision for them and their family and I think that's something that's not happening at the moment.
[00:22:15] Wil: And specifically in a Canadian context, it's so difficult because as a society, we place so much pride in our healthcare system, which contributes to vaccines, but you also place a lot of pride in our ability to exercise our philosophical, religious rights.
[00:22:29] So it's difficult where you can't really have one or the other or you can only just have one because it goes against our idea of what our society should be.
[00:22:37] Sully: Or maybe it's just a misunderstanding of how beliefs oppose vaccines in the first place, because of the lack of education.
[00:22:44] Wil: Another point that I wanted to add regarding the source of vaccine hesitancy.
[00:22:50] We're talking about this more from a context of a higher income developed country, right? And individuals in developed countries often wink vaccine [00:23:00] preventable disease. With the lower-income or the developing countries. I often hear people saying that, oh, things like measles or other vaccine preventable diseases don't exist in places like north America or Western Europe that are typically well-developed.
[00:23:16] And when you have this kind of mindset you can easily have large portions of the population simply just disregard the need for vaccine because they believe that they themselves will not be effected. And since they don't understand the idea of herd immunity or some altruism component of it, they completely don't see a need to be vaccinated and, or they're just reluctant for it and which contributes to more and more vaccine hesistency.
[00:23:41] Gordon: Like you're saying there's a nonchalant attitude because you don't perceive it as an imminent threat, and I know public health struggles with risk communication and risk perception. People may not perceive this as a threat, but as we've seen with COVID-19 infectious diseases are [00:24:00] spread because of globalization and mobility.
[00:24:02] Communities are no longer isolated from one another. All it takes is one person moving to an area with an active outbreak of disease and then bringing it back. So people under appreciate the kind of danger infectious disease carries when they're not truly eradicated yet, for smallpox, theoretically, if there's a disease that is no longer circulated anywhere and there's no humans effected you can then make the argument that the vaccine is no longer needed because the virus has not been detected anywhere.
[00:24:31] But for circulating viruses and globalization it's a matter of time before it gets to some communities, right? So that's a really important point. So I just wanted to move it more along. So we talked about the contributing factors of vaccine hesitancy, but what are the public health consequences of an increase in vaccine hesitancy?
[00:24:51] Ben: So a direct consequence of that would be a decline in immunization rates. So we're not able to achieve herd immunity, therefore we're ineffective in limiting the rapid [00:25:00] disease and this is also due to a distrust of scientific evidence. So it's hard for us to make public health recommendations based off scientific evidence if people don't trust the scientific evidence.
[00:25:11] Leshawn: Yeah. And one of the indirect consequences would be an increased in vaccine preventable disease outbreak. Measles was once officially eliminated in the U S with less than a hundred Americans each year being diagnosed with it, but this number started to climb since 2011 with the notable spike that we may have heard in the news in 2014.
[00:25:31] Gordon: Another consequence is the whole children missing school piece. Ben talked about some of the legislation and acts that require kind of students to be suspended. If they're not up to date on immunizations, these students are now missing school, missing education and parents are now having to take time off work.
[00:25:50] So that's lost income and an opportunity cost as well. So there is an economic component affected as well when immunization rates do not reach [00:26:00] the herd immunity levels.
[00:26:01] Wil: So the world health organization said that the disruption of immunization services, even for brief periods will result in increased numbers of susceptible individuals and raise the likelihood of outbreak prone vaccine preventable diseases.
[00:26:16] And these disruptions may occur in several ways. For example, the current COVID 19. What do you guys think are the implications that this pandemic may have on future attitudes, towards immunization and vaccinations in general?
[00:26:31] Leshawn: We see that in a lot of low and middle income countries, there's a lot of vaccination advocacy initiatives to increase the uptake of vaccines.
[00:26:41] A lot of this work requires individuals and volunteers to go door to door, or house to house, give reminders or give information to individuals regarding vaccines because of the physical distancing measures that have been recommended it seems like these advocacy initiatives [00:27:00] may have to halt for a bit or choose between following these restrictions imposed on them or vaccinations in your population.
[00:27:08] Wil: And so how would this affect the future attitudes towards vaccines?
[00:27:12] Leshawn: I was looking into some other work done by the Canadian Institute of health research, the CIHR as a part of the COVID-19 rapid response initiative and some of their research show that about 20% of individuals said that should a vaccine become available, they're likely not to take it. And the sample size for this, at least the first wave of the research was around 7,000 people in Canada and the United States, but still having 20% of people not wanting to take a vaccine that would help prevent COVID 19 is definitely something to be concerned about.
[00:27:48] Gordon: It was interesting because normally in Canada, anyway, the percentage of people who are considered vaccine hesitant is around 20 to 30%.
[00:27:58] So what you're saying Leshawn [00:28:00] is that given, even though we've seen the complete carnage COVID-19 has caused vaccine hesitancy hasn't really moved and that's a deep seated mistrust for government and science altogether, I would say.
[00:28:13] So vaccines are the epitome of public health and merit so closely because like public health, if you don't hear about a disease anymore, it means the vaccines are working public health efforts, particularly in the case of vaccines and vaccine preventable diseases is a victim of its own success as over 100 different COVID-19 vaccine candidates are being fast-track towards the development with the hopes of addressing the ongoing crisis. We must not forget about the vaccines that are already available, that saved millions of lives each year. Public health needs to understand the unique needs of each population, including the socio-cultural aspects and develop trust, even when vaccinations are not mandatory.
[00:28:56] Narrator: Thanks for listening. Remember public [00:29:00] health is a field of inquiry and an arena for action to improve lives. One population at a time. This has been the Public Health Insight podcast. If you've enjoyed this episode, please drop us a like and follow us on Spotify, Apple podcast, Google podcast, or your podcast platform of choice.
[00:29:16] You can also send us your question, comments, and suggestions for discussion topics at publichealthinsight@gmail.com. Thank you for listening and we'll see you in the next episode.