Parents have a responsibility not only to their own children, but to their communities—it’s only by achieving a very high level of population immunity that outbreaks can be prevented. Vaccination is particularly crucial for children with cancer and other diseases that cause immunosuppression. They cannot be vaccinated safely, but are at high risk of severe consequences if they are infected—and, thus, they depend on the community’s so-called “herd immunity” for protection against a potentially fatal illness.
While some parents continue to express concern about a possible link between vaccines and autism spectrum disorders, the original report claiming this connection has been debunked and retracted. A large number of carefully designed follow up studies have been carried out, and the overwhelming weight of scientific evidence shows no evidence for such a link. That’s why it continues to be so important to get the word out to parents: Have your kids vaccinated.
South and North America have eradicated Rubella virus with use of vaccines (which DO NOT cause autism)!! This is the third virus that has been eliminated from the Americas using vaccines. More info here at NPR.
The Americas have led the way when it comes to eradicating diseases. It was the first region in the world to eradicate smallpox in 1971 and then polio in 1994. And the PAHO (Pan American Health Organization) already has its sights on another target.
However, elimination of this virus, or others, does not mean people should stop vaccinating. It demonstrates the importance and effectiveness of vaccination.
The eradication of rubella doesn’t mean we’ll never see the virus again in the U.S. People still bring it here from other countries. But it doesn’t spread far because so many Americans are vaccinated.
Despite the success of vaccines in eradicating these harmful and lethal diseases, there is still more to do!
“With rubella under our belt, now it’s time to roll up our sleeves and finish the job of eliminating measles as well,” Etienne (director of PAHO) said.
I guess PAHO should start in California, hahahaha (not really funny). Who said vaccines are ineffective??? And what did they base that lie on??
Measles was eliminated from the United States in 2000 – with elimination defined as “the absence of continuous disease transmission for 12 months or more in a specific geographic area”. But in 2014 things began to unravel when the US experienced its largest number of measles cases ever, and later at the beginning of 2015 when a measles outbreak began in Disneyland and subsequently spread to multiple states. The primary cause of the California measles outbreak was parents who chose not to vaccinate their children because of unwarranted fears that vaccines were linked to autism, despite the fact that such connections have been disproven in the scientific literature. As both a parent of a child who is severely disabled by autism and other mental disabilities and a vaccine researcher and head of a non-profit vaccine product development partnership, I like to also point out the absence of any scientific plausibility for connecting autism to vaccines (Thoughts on World Autism Awareness Day).
I am troubled – the world looks to the United States as a trend setter in many different fields ranging from cinema to the sciences. Vaccine hesitancy is a trend that should never be imitated.
– Peter Hotez, President of the Sabin Vaccine Institute and Texas Children’s Hospital Center for Vaccine Developmentannouncing the launch of PLOS Currents Outbreaks collection on Vaccine Hesitancy
Check out the STORIFY I wrote summarizing a twitter discussion about vaccines… or so I thought. It involves an anti-vaccine troll ignoring facts and science to argue against vaccines, while spewing misinformation and conspiracy theories! Language warning – some of the tweets include swearing (not from CauseScience). Thanks to @divyaramjee and @sassyinmyheart for supporting vaccines. Trolls like this are not far removed from the anti-vaccine movement, and represent what science is fighting against when it comes to vaccines.
In recent weeks we’ve seen an alarming outbreak of measles; a highly contagious and serious virus, especially in babies and young children who have not been vaccinated. This outbreak is particularly disturbing because measles was effectively eliminated from the United States in 2000 thanks to nearly universal vaccination, the single best way to prevent the spread of this disease.
Vaccination works with the body’s natural defenses to help it safely develop immunity to the measles. When more people are vaccinated, there are fewer opportunities for the disease to spread. A community generally needs more than ninety per cent of its members to be immunized against the virus in order to protect those who can’t be.
Before the first measles vaccine was approved in 1963, hundreds died from the disease each year. Others developed pneumonia, lifelong brain damage or deafness.
Let’s not return to these grim statistics. There is no shortage of measles vaccine. It should be used by everyone who has not been vaccinated to prevent measles and the potentially tragic consequences of the disease.
Columbia University Mailman School of Public Health – Seven Myths About Measles
Melissa Stockwell, MD, MPH, a pediatrician and assistant professor of Population and Family Health at the Mailman School of Public Health and assistant professor of Pediatrics at the College of Physicians and Surgeons, both at Columbia University, debunks seven common myths about measles and vaccination.
Remember Kaci Hickox? The nurse that New Jersey Governor Chris Christie quarantined when she returned from West Africa during the ebola outbreak because he ignored the science and gave into Ebola fear-mongering? She is now calling out the Governor for his anti-science stances, this time when it comes to his recent statements on vaccines. Turns out Kaci has a heck of a lot more experience with measles than Chris Christie!! More info on Kaci’s statements here.
I think this is a good example of Gov. Christie making some very ill-informed statements. We heard it a lot during the Ebola discussion, and now it seems to have happened again.
We know that vaccines are safe, and we know that vaccines save lives. I have worked in a measles outbreak in northern Nigeria before. We were seeing about 2,000 children a week with measles. It is a scary disease. I know that these families of these 100 people who have the disease now could tell you a little bit about what the disease looks like and how much misery it causes. After the vaccine was implemented in 1963, there was a large reduction in cases, about 98 percent. And I believe it was 1989 to ’91, there was a resurgence. … The stakes are high. We have to protect our most vulnerable populations. – Kaci Hickox
Herd immunity and measles: why we should aim for 100% vaccination coverage
The measles outbreak traced back to Disneyland has spread to eight states, with as many as 95 cases reported by January 28. Media outlets are highlighting the rise of anti-vaccination sentiments. Scientists are expressing their dismay at people who reject sound medical advice and put their families and communities in harm’s way.
The narrative during this outbreak, or any measles outbreak really, is that measles is a highly transmissible disease. So transmissible in fact that 90–95% of people must be vaccinated in order to protect the entire population, or achieve what is called herd immunity.
That is partly true. Measles is highly transmissible, not least because people can be contagious days before symptoms develop. But there are three problems with this line of reasoning about vaccination rates.
First, the numbers are based on calculations that assume a world of random mixing. Second, the vaccination coverage is not a perfect measure of immunity in the population. Third, and most problematic in my view, it gives people a seemingly scientific justification for not getting vaccinated – after all, if not everyone needs to get vaccinated in order to attain herd immunity, can it really be so bad if I opt out of it.
What exactly is herd immunity?
Let’s look at the concept of herd immunity first. The basic idea is that a group (the “herd”) can avoid exposure to a disease by ensuring that enough people are immune so that no sustained chains of transmission can be established. This protects an entire population, especially those who are too young or too sick to be vaccinated. But how many people need to be immune to achieve this?
In order to calculate the number of people who need to be immune for herd immunity to be effective, we need to know how many people will get infected, on average, by an infectious person.
Imagine that a newly infected person will on average pass on the disease to two other people. Those two will each infect another two people, who will themselves pass it on, and so on, resulting in the classical pattern of an exponentially growing outbreak.
In order to stop the growth in the number of transmissions, we need to ensure that each individual case causes, on average, less than one new infection. So, let’s say that one case leads on average to two more infections, but instead we want that number to be less than one. That means at least 50% of the population needs to be immune, so that at most, only one of the two people who might have been infected by an individual will be.
How many people need to get vaccinated to achieve herd immunity?
So, how do we calculate what fraction of a population needs to be immune to reach herd immunity? First, we need to know what the reproduction number, or R, is. That’s how many new cases a single case of an infection will cause.
Imagine that you are infected in a completely susceptible population, and you pass on the infection to five other people (ie R=5). In order to prevent an outbreak, at least four out of those five people, or 80% of the population in general, should be immune. Put differently, 20% of the population may remain individually susceptible, but the population would still remain protected.
So if you can estimate the reproduction number for a given disease, you can calculate the fraction of the population that needs to be immune in order to attain herd immunity.
For influenza and Ebola, the number R is about two. For polio and smallpox, it is around five to eight. But for measles it is much higher, somewhere between 10 and 20. And because of that, the goal for measles vaccination coverage is typically around 90-95% of a population.
But there’s a problem with this calculation.
The population is not random
The assumption underlying the calculation for herd immunity is that people are mixing randomly, and that vaccination is distributed equally among the population. But that is not true. As the Disneyland measles outbreak has demonstrated, there are communities whose members are much more likely to refuse vaccination than others.
Geographically, vaccination coverage is highly variable on the level of states, counties, and even schools. We’re fairly certain that opinions and sentiments about vaccination can spread in communities, which may in turn lead to polarized communities with respect to vaccination.
And media messages, especially from social media, may make the problem worse. When we analyzed data from Twitter about sentiments on the influenza H1N1 vaccine during the swine flu pandemic in 2009, we found that negative sentiments were more contagious than positive sentiments, and that positive messages may even have back-fired, triggering more negative responses.
And in measles outbreak after measles outbreak, we find that the vast majority of cases occurred in communities that had vaccination coverages that were way below average.
The sad truth is this: as long as there are communities that harbor strong negative views about vaccination, there will be outbreaks of vaccine-preventable diseases in those communities. These outbreaks will happen even if the population as a whole has achieved the vaccination coverage considered sufficient for herd immunity.
If negative vaccination sentiments become more popular in the rest of the population as well, we may start to see more sustained transmission chains. Once those chains are sufficiently frequent to connect under-vaccinated communities, we may again be in a situation of endemic measles.
The solution often proposed is that we should do a better job of convincing people that vaccines are safe. I’m all for it. But I would also suggest that we should stop basing our vaccination policies on models that made sense in a world of constrained vaccine supply, and aim for 100% vaccination coverage among those who can get vaccinated.
This would also solve another problem, often glanced over: There are many people who cannot get vaccinated for medical reasons, either because they are too young, or because they have other conditions that prevent them from acquiring immunity through vaccination.
Herd immunity against measles requires that 90-95% of the entire population are immune, whereas vaccination coverage is measured as the percentage vaccinated of the target population – which only includes people who are eligible for vaccination. This means that to achieve 95% immunity in the population for measles, vaccination coverage needs to be higher than 95%. This is the scientific argument for a public health policy that aims at 100% vaccination coverage.
More importantly, there is an ethical argument to be made for the goal of 100% vaccination coverage. It sends the right message. Everyone who can get vaccinated, should get vaccinated – not only to protect themselves, but to protect those who can’t, through herd immunity.
HELLO SCIENCE!! A lot of you want to talk about science deniers, that’s what you are people! You non-vaxxers, you’re science deniers. That’s it!
A small minority of parents refuse vaccines for their children citing all kinds of weirdness, including a possible link to autism, which science says DOES NOT EXIST. And according to the CDC, there is absolutely no link to autism. And anti-vaxxers are hurting all the other little children by not letting little Johnny and little Janey get their shots. Get your shots, come’ on now!
– Shepard Smith
Honestly… I think this is my favorite #Science Quotable ever!! Video below.
Fox Host Shep Smith To Anti-Vaxxers: ‘You’re Science Deniers!’
I’ve heard of many tragic cases of walking, talking, normal children who wound up with profound mental disorders after vaccines. I’m not arguing vaccines are a bad idea. I think they’re a good thing. But I think the parents should have some input. – Senator Rand Paul during a CNN interview
Were these tragic cases based on science?? The worst and most hypocritical was yet to come. Paul sent a followup email to CNN elaborating and slightly backpedaling.
Dr. Paul believes that vaccines have saved lives, and should be administered to children. His children were all vaccinated. He also believes many vaccines should be voluntary and like most medical decisions, between the doctor and the patient, not the government.
As a “doctor”, I would hope that Senator Paul would recognize the weaknesses introduced by voluntary vaccination. What if his children were unable to be vaccinated? Or what about when they were too young to be vaccinated as babies? These children can only be protected by high vaccine rates among people who can get them.