Vaccines Are the Safest Medical Procedure We Have. Make Your Wager Wisely.
Frontline infectious disease physician Amesh Adalja received his COVID-19 vaccine on December 18th, 2020 in Butler, PA.
In the late 1650's the French polymath and renowned scientist Blaise Pascal, having undergone a religious experience that transformed him into something of a zealot, suggested the following logical strategy regarding belief in God: If there is a God, then believing in him will ensure you an eternity of bliss, while not believing in him could earn you an eternal sentence to misery.
On the other hand, if there is no God, believing in him anyway will cost you very little, and not believing in him will mean nothing in the non-existent after life. Therefore, the only sensible bet is to believe in God. This has come to be known as Pascal's wager.
It has a surprising number of applications beyond concerns for a comfortable afterlife. There are many things for which the value of believing something or not can be seen as a cost vs. likely benefit wager, often without regard to the actual truth of the matter. Since science does not profess to have a final truth, and in many areas freely admits its incomplete knowledge, Pascal's wager can provide a useful method of deciding between two alternatives.
For example, it seems that a significant percentage of the population is suspicious of science, or so we are told. We often hear that some large number, approaching or exceeding half of Americans, do not believe in evolution. This seems remarkable on the face of it because there is no viable scientific opposition to evolution and it is widely accepted by biologists and other life-scientists as being fundamental to understanding biology – from genetics to medicine.
What we are not often told is that most of those who answer negatively about believing in evolution nonetheless understand evolution – or at least the basics of it. They are not stupid, ignorant or uninformed. They have simply made a Pascalian wager. What benefit we might ask is derived from believing in evolution rather than a divine creation? Unless you are a professional biologist it is hard to see how this would affect your everyday life. On the other hand professing a belief in Darwinian evolution over the biblical narrative will likely ostracize you from family, friends, co-workers, your church community - in short most of your social infrastructure. Place your bets.
Can we apply any of this to decisions over the current controversy surrounding vaccination – and in particular the newly arrived Covid-19 vaccine?
While it is true that for entirely economic reasons, this is the first vaccine to be produced in this way, the method is not really new and the science that makes it possible has been developing over the last 40 years.
Common Concerns
There are certainly reasons to be concerned about being vaccinated and it would be a gross over-simplification to consider anyone who expresses reticence about taking a vaccine, this new vaccine in particular, as being just plain dumb or scientifically illiterate or gullible. They need be none of these things and still may be suspicious of the vaccine.
One issue is safety. The vaccine, any vaccine, is designed to mobilize your immune system, essentially to fool it into believing that there is an invading virus present and to mount an immune response. That way it will be ready when the real invasion comes, if it comes. This seems pretty sensible and preferable to going to war with an opponent you know nothing about. But still, it is fooling around with Mother Nature and some people are uneasy about that. Although it must be pointed out that the virus is not at all shy about fooling around with your immune system and many other parts of you, so letting it have its way is not good policy either.
What about a vaccine made of genes? This vaccine is being produced by what is being touted as a new method using RNA – genes. While it is true that for entirely economic reasons, this is the first vaccine to be produced in this way, the method is not really new and the science that makes it possible has been developing over the last 40 years. So it's not so radical as the press makes it seem.
But it is true that this method uses RNA, genetic material, to make the vaccine. We hear a lot about gene modification and the potential dangers associated with it. Why then am I going to allow RNA, genes, to be injected into me? The first thing to realize is that this is exactly what the virus does – so whether you get a vaccine or an infection, you are getting genes injected into you. The virus RNA encodes around 12 functional genes (by comparison humans and other mammals have around 25,000 genes). The virus only contains the genes to make a new virus – it does not have any of the capabilities of a normal cell to actually turn those genes into the proteins that make up the complete virus. It hijacks your cells to do this – and that's how it sickens you, by forcing your cells to make new viruses instead of what they should be doing.
Now the new vaccines have taken just one of those genes – the one that directs the production of the now infamous spike protein that appears on the surface of a normal virus – and injects just that one gene into your muscle cells, which then make that one single protein. Your immune system comes along and sees that weird protein and makes antibodies to it. These same antibodies will now recognize the spike protein on the surface of any viral particles that invade your body. We have effectively turned the virus into its own enemy.
The viral RNA that you are getting will decompose over a few days because RNA is not a stable molecule (that, by the way, is why the vaccine needs to be kept frozen) and it will no longer exist in your body. It could only become a permanent part of your genome if it were a DNA molecule instead of an RNA molecule – and even the chances of that happening would be chemically remote. So regardless of how it sounds, this may actually be the safest sort of vaccine to use. In the future it is likely that all vaccines will be made this way.
Then, of course, there is the issue of who is running this whole vaccine program – the government and the pharmaceutical industry. These are the guys who brought you opioid addiction, death by Vioxx, soaring drug prices, the worst health care system in the developed world, regulations where you don't need them and none where you do – am I really going to trust this cast of so-called "inept villains," as some believe, to dictate my personal health choices? Do we know for sure that the claims of efficacy are real or just made up to sell some worthless procedure? It would not be the first time. (I would not, on the other hand, worry about Bill Gates having a chip inserted into you along with the vaccine – if you use any social media, navigational tools, or purchase anything online, then Bill Gates already knows more about you than he will get from any injectable chip. So that train has left the station.)
The main upside to vaccines is that because they use your already existing defense system, they are surprisingly safe.
The Vaccine Wager
All this and a few lesser issues are worth a pause for sure. But we must also look on the positive side of the ledger. Why trust science? Modern medicine and the science behind it has eliminated or dramatically lessened such scourges as smallpox, polio, cholera, chicken pox, measles, rabies and dozens of other killer pathogens that had previously wiped out enormous numbers of people, in some cases significant parts of entire generations. Don't we depend on science for much of the comfort and safety of our everyday lives? Isn't science the way we heat our homes, drive to work, fly around the world, have dependable food? Yes, there is the bomb – but there is also anesthesia.
When it comes to viruses, the only tool we have to fight them is vaccination. The only tool. Antibiotics are for bacteria, a completely different sort of creature. Sanitation beyond personal hand washing is ineffective. Vaccines trick the immune system into recognizing the virus earlier than it would otherwise and protect normal cells from invasion by the virus. Tricking the immune system is understandably problematic for people who believe that their body knows best if it's just kept healthy. This virus, as we have seen from the array of infected people that includes apparently healthy folks, unfortunately does not subscribe to that belief.
By a similar sort of reasoning, some people make the plausible error of calculating that the vaccine is 95% effective but the survival rate is 99%, so why not just let my natural resistance take care of this? Indeed, that might not be unreasonable thinking if we were talking about the common cold, but this virus has shown itself to be a tricky character and we are not yet able to predict who gets a serious case and who a mild one. With those sorts of stakes, you shouldn't wager on either of those numbers because they have nothing to do with you as an individual. Like flipping a coin, there is only a 1% chance of it coming up heads 6 times in a row. But if it has come up heads 5 times in a row the probability of it coming up heads on the next flip is … still 50/50.
An even larger unknown is whether there may be long-term effects associated with SARS-Cov-2, as is the case for many viruses. The 1918 influenza virus has been linked to a subsequent 2-3 fold increase in Parkinson's disease by a mechanism we still don't understand. The virus that gives children chicken pox will hide out in a person's body for 40 years or more and then emerge as a painful, sometimes debilitating, case of shingles. The 99% survivability rate of this virus is meaningless if 20 years from now it causes some devastating pulmonary or brain disease.
The main upside to vaccines is that because they use your already existing defense system, they are surprisingly safe. Safer than antibiotics which have numerous side effects because they are not part of our normal make up and are cell killers – mostly bacterial cells, but they are not so perfectly targeted that they don't leave some collateral damage in their wake. All drugs and treatments have side effects, but vaccines in general have the fewest. This vaccine in particular has undergone many more than the usual safety measures - multiple independent review boards, massive press and public attention, governmental and non-governmental oversight, the most diverse trial cohorts ever assembled. Nothing here was rushed, no shortcuts were taken.
So here's the vaccine wager. Vaccines are the safest medical procedure we have. They are also among the most effective, but that's curiously not important for the bet. My claim about their safety is because vaccines are in a special class of medical tools. They are the only medical procedure or drug that is given to healthy people. Every other treatment we use medically is aimed at some existing pathology - from a cold to cancer.
Vaccines therefore have to reach a higher standard of safety than any other medical treatment. You can't take healthy people and make them sick. Vaccines have fewer side effects than virtually any other drug you wouldn't even think twice about taking – aspirin, for instance, which can cause internal bleeding, gastric ulcers, stroke. But since you are sick when you take those drugs you are willing to make the bet that the benefits will outweigh the possible side effects.
With vaccines the wager is much simpler – it is indeed more like Pascal's original wager. It may or may not be highly effective (some vaccines are only 60% effective) but they are so safe that taking them poses little risk, whereas not taking them subjects you (and others) to considerable risk, i.e., getting the virus. Like believing or not in an afterlife, the smart money is with Pascal, who I think would have reasoned himself right to the head of the vaccination line.
Catching colds may help protect kids from Covid
A new study shows that the immune system's response to colds can help prepare it to defend against COVID-19 - but only in the very young.
A common cold virus causes the immune system to produce T cells that also provide protection against SARS-CoV-2, according to new research. The study, published last month in PNAS, shows that this effect is most pronounced in young children. The finding may help explain why most young people who have been exposed to the cold-causing coronavirus have not developed serious cases of COVID-19.
One curiosity stood out in the early days of the COVID-19 pandemic – why were so few kids getting sick. Generally young children and the elderly are the most vulnerable to disease outbreaks, particularly viral infections, either because their immune systems are not fully developed or they are starting to fail.
But solid information on the new infection was so scarce that many public health officials acted on the precautionary principle, assumed a worst-case scenario, and applied the broadest, most restrictive policies to all people to try to contain the coronavirus SARS-CoV-2.
One early thought was that lockdowns worked and kids (ages 6 months to 17 years) simply were not being exposed to the virus. So it was a shock when data started to come in showing that well over half of them carried antibodies to the virus, indicating exposure without getting sick. That trend grew over time and the latest tracking data from the CDC shows that 96.3 percent of kids in the U.S. now carry those antibodies.
Antibodies are relatively quick and easy to measure, but some scientists are exploring whether the reactions of T cells could serve as a more useful measure of immune protection.
But that couldn't be the whole story because antibody protection fades, sometimes as early as a month after exposure and usually within a year. Additionally, SARS-CoV-2 has been spewing out waves of different variants that were more resistant to antibodies generated by their predecessors. The resistance was so significant that over time the FDA withdrew its emergency use authorization for a handful of monoclonal antibodies with earlier approval to treat the infection because they no longer worked.
Antibodies got most of the attention early on because they are part of the first line response of the immune system. Antibodies can bind to viruses and neutralize them, preventing infection. They are relatively quick and easy to measure and even manufacture, but as SARS-CoV-2 showed us, often viruses can quickly evolve to become more resistant to them. Some scientists are exploring whether the reactions of T cells could serve as a more useful measure of immune protection.
Kids, colds and T cells
T cells are part of the immune system that deals with cells once they have become infected. But working with T cells is much more difficult, takes longer, and is more expensive than working with antibodies. So studies often lags behind on this part of the immune system.
A group of researchers led by Annika Karlsson at the Karolinska Institute in Sweden focuses on T cells targeting virus-infected cells and, unsurprisingly, saw that they can play a role in SARS-CoV-2 infection. Other labs have shown that vaccination and natural exposure to the virus generates different patterns of T cell responses.
The Swedes also looked at another member of the coronavirus family, OC43, which circulates widely and is one of several causes of the common cold. The molecular structure of OC43 is similar to its more deadly cousin SARS-CoV-2. Sometimes a T cell response to one virus can produce a cross-reactive response to a similar protein structure in another virus, meaning that T cells will identify and respond to the two viruses in much the same way. Karlsson looked to see if T cells for OC43 from a wide age range of patients were cross-reactive to SARS-CoV-2.
And that is what they found, as reported in the PNAS study last month; there was cross-reactive activity, but it depended on a person’s age. A subset of a certain type of T cells, called mCD4+,, that recognized various protein parts of the cold-causing virus, OC43, expressed on the surface of an infected cell – also recognized those same protein parts from SARS-CoV-2. The T cell response was lower than that generated by natural exposure to SARS-CoV-2, but it was functional and thus could help limit the severity of COVID-19.
“One of the most politicized aspects of our pandemic response was not accepting that children are so much less at risk for severe disease with COVID-19,” because usually young children are among the most vulnerable to pathogens, says Monica Gandhi, professor of medicine at the University of California San Francisco.
“The cross-reactivity peaked at age six when more than half the people tested have a cross-reactive immune response,” says Karlsson, though their sample is too small to say if this finding applies more broadly across the population. The vast majority of children as young as two years had OC43-specific mCD4+ T cell responses. In adulthood, the functionality of both the OC43-specific and the cross-reactive T cells wane significantly, especially with advanced age.
“Considering that the mortality rate in children is the lowest from ages five to nine, and higher in younger children, our results imply that cross-reactive mCD4+ T cells may have a role in the control of SARS-CoV-2 infection in children,” the authors wrote in their paper.
“One of the most politicized aspects of our pandemic response was not accepting that children are so much less at risk for severe disease with COVID-19,” because usually young children are among the most vulnerable to pathogens, says Monica Gandhi, professor of medicine at the University of California San Francisco and author of the book, Endemic: A Post-Pandemic Playbook, to be released by the Mayo Clinic Press this summer. The immune response of kids to SARS-CoV-2 stood our expectations on their head. “We just haven't seen this before, so knowing the mechanism of protection is really important.”
Why the T cell immune response can fade with age is largely unknown. With some viruses such as measles, a single vaccination or infection generates life-long protection. But respiratory tract infections, like SARS-CoV-2, cause a localized infection - specific to certain organs - and that response tends to be shorter lived than systemic infections that affect the entire body. Karlsson suspects the elderly might be exposed to these localized types of viruses less often. Also, frequent continued exposure to a virus that results in reactivation of the memory T cell pool might eventually result in “a kind of immunosenescence or immune exhaustion that is associated with aging,” Karlsson says. https://leaps.org/scientists-just-started-testing-a-new-class-of-drugs-to-slow-and-even-reverse-aging/particle-3 This fading protection is why older people need to be repeatedly vaccinated against SARS-CoV-2.
Policy implications
Following the numbers on COVID-19 infections and severity over the last three years have shown us that healthy young people without risk factors are not likely to develop serious disease. This latest study points to a mechanism that helps explain why. But the inertia of existing policies remains. How should we adjust policy recommendations based on what we know today?
The World Health Organization (WHO) updated their COVID-19 vaccination guidance on March 28. It calls for a focus on vaccinating and boosting those at risk for developing serious disease. The guidance basically shrugged its shoulders when it came to healthy children and young adults receiving vaccinations and boosters against COVID-19. It said the priority should be to administer the “traditional essential vaccines for children,” such as those that protect against measles, rubella, and mumps.
“As an immunologist and a mother, I think that catching a cold or two when you are a kid and otherwise healthy is not that bad for you. Children have a much lower risk of becoming severely ill with SARS-CoV-2,” says Karlsson. She has followed public health guidance in Sweden, which means that her young children have not been vaccinated, but being older, she has received the vaccine and boosters. Gandhi and her children have been vaccinated, but they do not plan on additional boosters.
The WHO got it right in “concentrating on what matters,” which is getting traditional childhood immunizations back on track after their dramatic decline over the last three years, says Gandhi. Nor is there a need for masking in schools, according to a study from the Catalonia region of Spain. It found “no difference in masking and spread in schools,” particularly since tracking data indicate that nearly all young people have been exposed to SARS-CoV-2.
Both researchers lament that public discussion has overemphasized the quickly fading antibody part of the immune response to SARS-CoV-2 compared with the more durable T cell component. They say developing an efficient measure of T cell response for doctors to use in the clinic would help to monitor immunity in people at risk for severe cases of COVID-19 compared with the current method of toting up potential risk factors.
In this week's Friday Five: The eyes are the windows to the soul - and biological aging?
Plus, what bean genes mean for health and the planet, a breathing practice that could lower levels of tau proteins in the brain, AI beats humans at assessing heart health, and the benefits of "nature prescriptions"
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on new scientific theories and progress to give you a therapeutic dose of inspiration headed into the weekend.
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Here are the stories covered this week:
- The eyes are the windows to the soul - and biological aging?
- What bean genes mean for health and the planet
- This breathing practice could lower levels of tau proteins
- AI beats humans at assessing heart health
- Should you get a nature prescription?