What determines whether we can create a vaccine for an illness or not?

Submitted by ShelfordPrefect t3_10kye24 in askscience

I'm curious what it is about certain types of infections that mean creating a vaccine is difficult or impossible. We created a vaccine for COVID-19 in months but have been working on one for HIV for decades.

What is it about scarlet fever, herpes etc. that make them more difficult to vaccinate against than polio, measles or meningitis?

It's been answered for HIV before: it attacks the immune system and mutates quickly - is it the same type of factors for other illnesses, or something else?

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FelisCantabrigiensis t1_j5txe0b wrote

HIV is like a rootkit on the software of your immune system: it destroys the very cells that would be sent to destroy it. That's why it's so hard to vaccinate against. Fortunately, we have very effective treatments to suppress it and we can, if we deploy these widely enough, expect to suppress it out of transmission in the foreseeable future. HIV isn't very easy to transmit so if you suppress it in the people who have it, it should die out when the oldest person with HIV dies of other causes, after spending their life with suppressed HIV.

Herpes is a sneaky bastard that hides out in nerve cells, out of the way of the immune system. The immune system can deal with it if it can find it, so that's why it hides.

Note that the work to be able to create a Covid vaccine has been in progress for decades. BioNTech (the actual inventors of the "Pfizer Covid vaccine") was founded 15 years ago and the more fundamental research on mRNA vaccines was done before the company was founded.

A huge amount of this understanding of viruses comes from the ability to sequence genomes. This is almost magical - it really is science fiction come to life. It's as magical as the "Star Trek communicator" becoming "cellphone in your pocket, works worldwide". The Human Genome Project required rooms full of thousands of expensive machines working for several years to sequence one genome. Today, you can do a full sequence of a human-size genome in less than a day (current record: 5 hours 22 minutes!). You can grab a random virus or bacterium and sequence it overnight, just to see what's interesting in its genome. If you find another one tomorrow, you can compare them over the weekend. This is a huge change for all life sciences.

It was sheer luck that mRNA technology was almost advanced enough to make vaccines for coronaviruses when SARS-CoV-2 (the virus that causes COVID-19) showed up. A lot of researchers worked a lot of overtime to turn "almost" into "actual" in an amazingly short time.

We also have a lot of experience making vaccines to viruses that the immune system can handle when suitably primed (i.e. NOT retroviruses like HIV, but most others) in other ways - using similar virus strains, culturing viruses and inactivating them, weakened live viruses, and so on. These methods had been used to produce vaccines for the SARS virus (the vaccines were not widely tested because by the time they were ready, there were too few cases to test and no need for them). The same techniques were also used to produce SARS-CoV-2 vaccines.

We can expect a lot more vaccines for diseases previously considered impossible to vaccinate against, using mRNA technology.

Aside from mRNA tech, research continues on other diseases. RSV (Respiratory syncitial virus) is a serious disease for infants, but attempts to make vaccines were disastrous in the past and the reason why the first attempts failed has only recently been understood after 30 years of work. This work doesn't even use mRNA knowledge, it's completely separate innovation.

Virology and immunology are both extremely complex topics which we have, across the world, not nearly mastered. We do not understand either, not even nearly, so the rate of advance of knowledge is rapid in both. When they intersect, they are both even more complicated. You have to see the current state of vaccines as a work in progress, where some problems have been solved and others have not, depending on random chance and whatever seems most important at the time.

I'm nearly 50 years old. In my lifetime, we have gone from commonplace vaccines for only a few things - polio, etc - to vaccines for a whole array of nasty diseases (measles, mumps, rubella, diptheria, typhoid, tetanus, pertussis, pneumococcus, influenza (moving target, alas), etc).

I expect in 50 more years, we'll have zapped most of them.

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quats5 t1_j5v4x5s wrote

I remember looking around about a decade ago and realizing that I hadn’t heard about chickenpox in a while.

I had a very light case when I was so young that I don’t remember it, so I’ve always known my immunity is likely negligible and that I need to be wary and stay clear of people who have it. It’s much more dangerous in adults.

….and then I realized I hadn’t had a mental alert of caution! Caution! Chickenpox! in… years.

So I Google and… oh. They made a vaccine for it in the 90’s, and it’s standard now. And practically nobody gets chickenpox any more because of this.

Nice.

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farrenkm t1_j5w9k8d wrote

I started working for a local hospital system around the turn of the century. They asked if I was up-to-date on my vaccines, and I said yes. Brought in the hep B documentation and everything.

Then they asked: have you ever had chicken pox? Dunno. Not that I'm aware of. They drew a titre and -- nope, no antibodies. They gave me the vaccine late 20's, early 30's. My next question, that I'll ask my MD, is if I need to worry about shingles. If I never had chicken pox, if I had the vaccine, should that be protection enough so I don't need to worry about it? My first reaction is "yes, that's true."

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NatAttack3000 t1_j5wdaph wrote

I had the chickenpox vaccine at about 24 and got chickenpox at 31, so you definitely still have a risk of getting chicken pox and possibly shingles though far less than if you didn't get vaccinated

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farrenkm t1_j5wkio1 wrote

Thank you. I thought that might be the case, so I was going to talk to my MD at my next physical. Reaching the age where this is a consideration . . .

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auraseer t1_j5z4nq1 wrote

CDC still recommends you get the shingles vaccine when you turn 50. We don't yet have proof that the chicken pox vaccine protects for your whole lifespan. It hasn't been around long enough to be sure, and we know that some kinds of immunity wane as the years pass.

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farrenkm t1_j6153ue wrote

Thanks for the response. Getting the vaccine doesn't bother me, I just didn't know if it was still a concern without having had chicken pox proper. That age isn't far off, so it's information I'll need.

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mradenovirus t1_j5v4cwo wrote

Rabies is an extremely slow virus. You can actually get bit and then go get the vaccine and be saved. That’s part of the reason we can be vaccinated for it. A primed immune system can still have time to react and clear

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ommnian t1_j5vynbe wrote

Yes, but also, when you're given the rabies vaccine in these cases, aren't *just* getting the rabies vaccine. You are also getting Rabies Immunoglobin. Which works alongside the vaccine to prevent the rabies virus from infecting you.

https://www.mayoclinic.org/drugs-supplements/rabies-immune-globulin-intramuscular-route/description/drg-20065738

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zebediah49 t1_j5x3s5u wrote

You probably don't actually need that.

But when the alternative is certain death, it's worth going the extra mile with the immunoglobin, just in case...

(Also, I certainly don't want to be part of the controlled trial to determine how necessary it is)

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FelisCantabrigiensis t1_j5v8436 wrote

That's true, and very unusual among viruses.

You can also be pre-emptively vaccinated for it, and then it works well too.

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saganmypants t1_j5wb1ov wrote

Amazingly, of the 14 vaccines routinely administered to babies today 8 of them were developed through the work of little known Maurice Hilleman and his team

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SkiNinja82 t1_j5x1otn wrote

woah that guy was awsome! i did micro as my undergrad with a small toe dipped into immunology but never heard of him during my studies!

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No-Turnips t1_j5wdzdz wrote

IF we all keep getting vaccinated. There are previously eradicated viruses making a resurgence in younger populations because of anti-vaxxing. Eradication depends on us ALL continuing to vaccinate.

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layzeeviking t1_j5y3ctf wrote

Expecting everyone to cooperate is an authoritarian pipe dream, and even then, there's all the viruses that also infect other animals (like sars-cov-2). We can live in a sterile box, or accept a certain risk.

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Suspicious_Ad_4768 t1_j5uof5a wrote

So herpes hides in the nerve cells. So does Rabies, but how do we have a vaccine for Rabies?

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FelisCantabrigiensis t1_j5uq5rq wrote

I haven't kept up with the exact differences, but I will say that rabies is 100% deadly and herpes is 0% deadly, which may affect the amount of effort put into this.

Rabies also does not hide out in nerves. It travels along nerves to the brain, but it doesn't hide there in a mostly-inactive state for a long time. It vigorously infects nerves and travels along them, which makes it more vulnerable to immune cells and also triggers more response from immune cells.

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dbx999 t1_j5xmcnr wrote

When a virus occupies the nerve cells and the brain, it’s like occupying an immune-free zone. The technical term I believe is immune privileged sites. These areas do not have immune system activity. This is probably why these viruses have adapted to occupy these sites.

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FelisCantabrigiensis t1_j5yqcpv wrote

Correct. Not least because immune activity killing off nerve and brain cells is a serious problem because they regrow slowly or never, so the compromise is that the immune system does not touch irreplaceable cells and aims to kill viruses and bacteria before they can reach those cells.

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dbx999 t1_j5yqww6 wrote

Worrisome that Covid is found in various areas including immune privileged sites as this indicates full recovery from the infection may not occur

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PerpetuallyLurking t1_j5uv6pk wrote

Yeah, the fact that no one dies OF herpes has a lot to do with the impetus to find a vaccine vs everyone who gets rabies dies. And even then HPV is related to herpes, can lead to cancer, and now has a vaccine. So…wait patiently, probably. They’re working on the deadly ones first, not the annoying ones that do have a reasonably easy treatment.

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SofaKingI t1_j5wa8kr wrote

Keep in mind that "hides" is a massive oversimplification.

Anyway, I don't think Rabies "hides" in the same sense as herpes. It doesn't lay dormant in your nerve cells for years until the next chance to cause an outbreak. It just infects nerve cells.

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Kenlaboss t1_j5w5git wrote

We truly live in the beginning of the modern era, and it's fantastic in a way to see history unfold before us.

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eazy_64 t1_j5wv9ms wrote

Nanotechnology as well. Wait until you hear about nanoscale microbots that can evade your immune response and deliver therapy or target specific cells.

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hollyjazzy t1_j5x71au wrote

Thank you for this beautiful explanation.I certainly hope your prediction at the end is correct, and that the anti vaxxers do not derail it. I remember when smallpox was declared extinct, it felt miraculous that such a deadly disease for centuries was no more. So many more diseases were on the cusp of being eradicated until distrust of vaccination started increasing immmensely in the early years of this century.

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mancapturescolour t1_j5xn7bv wrote

> Fortunately, we have very effective treatments to suppress it and we can, if we deploy these widely enough, expect to suppress it out of transmission in the foreseeable future. HIV isn't very easy to transmit so if you suppress it in the people who have it, it should die out when the oldest person with HIV dies of other causes, after spending their life with suppressed HIV.

Yes, it's effective and cheaper than ever.

> If properly adhered to, ARV treatment, which costs as little as 20 cents a day, not only keeps an HIV-positive person alive and healthy, but also reduces the risk of transmission.
Source: https://www.red.org/our-impact-areas/#testing-and-treatment

Now the game-changer in all this, for me, is that supressing HIV during pregnancy prevents mother-to-child transmission of the virus. That means a child to a HIV+ parent can be HIV free at birth! So, we don't have to wait for HIV to die out with old age, there are people already born HIV- thanks to these drugs. The United States have made a significant impact through PEPFAR in the last 20 years (this Saturday!) but we rarely hear about that success story.

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[deleted] t1_j5yq4tt wrote

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mancapturescolour t1_j5z0ck9 wrote

Thank you, that is very important to point out. I appreciate your insights, it's so valuable to share.

It's a multifaceted issue and what you state, adherence, is a key point indeed: Undetectable = Untransmittable aka (U=U). For that to happen people that need these ARVs must have access, and be comfortable to take them regularly for a long time.

We're not there yet but I believe we will have the means to turn this epidemic around completely. Whether by vaccines, replacing stigma by normalization of what life with HIV is today, or arriving at an HIV free generation...as long as there's a will, there's a way. Just the idea that you can lead a "healthy" and normal life with HIV today is so mind-blowing compared to how it was only a few decades ago.

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smash8890 t1_j5x45yk wrote

Why did the RSV vaccine fail?

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MazerRakam t1_j5xj36h wrote

Combination of a lot of factors, vaccine research was still fairly new and virology wasn't nearly as well understood as it is now. They were targeting the wrong proteins and getting frustrated that they weren't getting the results they expected. Come to find out, RSV actually changes shape (protein unfolding) after it enters the cell. This is important because antibodies can only prevent a cell from getting infected, antibodies cannot enter a cell and push the virus out. So researchers were taking infected cells, analyzing the virus in those cells (after it changed shape) and tried to make a vaccine that would teach the immune system target those structures. But those structures weren't found outside the cell, and the immune response was hindered because of that.

Luckily, someone figured that out, and they redirected their focus and were able to create a vaccine that teaches the immune system to target the virus structure before it enters the cell and now RSV vaccines actually work the way they should.

https://www.nature.com/articles/d41586-021-03704-y#:~:text=Tragically%2C%20the%20shot%20did%20the,the%20trial%20and%20killed%20two.

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[deleted] t1_j5u2r2d wrote

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blp9 t1_j5uhmq0 wrote

>(also during all years of mrna development it was never tested on humans)

This is a table with at least a dozen completed human clinical studies for mRNA cancer treatments prior to 2017.

While this is a table of mRNA infectious disease trials, with at least 3 of them completed. Also all prior to 2017.

This is from a journal article published in 2018.

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LSeww t1_j5untbx wrote

Most of them are I/II phases studies (dozens to low hundred participants), only two at phase III, of which one is terminated (no desirable effects) another is expected to end in 2023. A decent amount of them were not even completed in 2019. So no, nothing was tested on humans at the time they decided to use if for covid. "Tested" means completed phase 3.

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blp9 t1_j5uv2dz wrote

That is a much better point than "it was never tested on humans".

Is your position that the Pfizer and Moderna Phase 3 trials were flawed in some way and therefore don't count?

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LSeww t1_j5uw7zb wrote

The point is: they chose a technology never (successfully) tested on humans for a “warp speed” vaccine development. Of course their phase 3 trials don’t count.

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Any-Broccoli-3911 t1_j5tx1yj wrote

Whether the immune system can beat it by itself if you survive it.

All the diseases we aren't to create a vaccine for (HIV, herpes, etc.) are diseases that your immune system is unable to beat.

For covid-19, your immune system will learn to beat it in a few weeks without a vaccine if you survive it. For those other diseases, if you have them, your immune system will never remove them from your body even if it has years to do so.

If a disease cannot be beaten with years of trying to learn how to beat it, it's unlikely than giving it a preview (which a vaccine is) will help.

It's because the viruses mutate fast and can hide from the immune system. For herpes, it hides inside neurons. For HIV, it hides inside CD4 T cells. The immune system isn't good at targeting neurons and T cells.

It's not because HIV attacks the immune system. It takes more than 10 years for HIV to destroy the immune system without treatment and it never does with treatment. The immune system is unable to beat it even when it's working well.

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sum_ergo_sum t1_j5uifxg wrote

Another factor not mentioned yet is that different types of viruses differ in mutation rate and mechanism of mutation due to biochemical differences in how their genetic material is stored and copied. Viruses with small genomes that mutate quickly, like HIV, can out-evolve vaccines more quickly. And in some viruses, like influenza, recombination allows for populations with new antigens to emerge quickly when multiple strains interact in the same organism (e.g. part of swine or bird flu could recombine with another strain and cause a novel flu strain), so we have to account for this when doing epidemiological predictions for targeting yearly vaccines.

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nexpermabad t1_j5w89bn wrote

Everyone mentioning HIV attacking the immune system is incorrect. The problem is that HIV is incredibly mutable. We create many antibodies that bind to HIV, however HIV can mutate to escape them. There is a conserved portion of HIV (the part where it binds to CD4 T-cells) that a few antibodies called broadly neutralizing antibodies (bnAbs) are able to target. However, these bnAbs are relatively rare, and tend to happen in patients who have had HIV for a while.

It's incredibly difficult to generate these bnAbs from a vaccine. Your body generates tailored antibodies through a process of mutation and selection called affinity maturation. These HIV bnAbs require a ton of mutation. There is research on trying to shepherd B cells through many rounds of mutation and selection to create these bnAbs by vaccinating with multiple different antigens, but this is still a very difficult problem.

Another difficult vaccine is malaria. We have vaccines that create antibodies that help protect against malaria. However, having antibodies to a foreign protein diminishes our ability to further develop an immune response to said foreign protein. As a result, current vaccine candidates have struggled with creating a large enough antibody response to generate strong protection.

Source: I'm a soon-to-be Ph.D. graduate in a computational vaccine design lab.

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FellowConspirator t1_j5urcxn wrote

To make a vaccine, the thing that you are making a vaccine against (typically a virus) needs to have a prominent protein on it's surface. The vaccine can be inactive virus, or parts, it doesn't matter, you just need to provide the foreign protein to the immune system so that it can learn to recognize it so when a virus tries to infect, the body is prepared to stop it.

Viruses mutate over time, and if the protein on the outside tends to change a lot, it can be difficult to make a vaccine against. It turns out that small changes in the protein can really change the shape, and it's the shape that the immune system recognizes. The other thing that can make it tricky is that some viruses tend to carry a bubble of fat around them that hides the protein so the immune system can't see it.

HIV is difficult because it has another trick up it's sleeve: it attacks the immune system itself, meaning that if it gets a foothold, a vaccine would be useless because your immune system can't fight back. AIDS, the disease caused by HIV, happens with the immune system pretty much fails because the virus has disabled it. The person starts getting all sorts of infections and cancers that they wouldn't normally get, and that's what makes it deadly.

COVID-19 was simple, for a few reasons: we're already familiar with this type of virus (we've known about coronaviruses for over 60 years, how they work, the genes in them, etc.) and they have whopping big proteins on the surface that don't change a whole lot with time. We also know have molecular biology technology developed in the past few years that makes it possible to rapidly sequence RNA, synthesize RNA, and deliver RNA to cells to express it. So, it took about 3 days to sequence the virus, and a few weeks, to synthesize the RNA message that could teach cells to produce the surface protein of the virus and teach the immune system to recognize it. The whole process could technically be done in a week -- the parts that slow it down are: scaling up production, setting up quality control to make sure it's consistent without contamination, and all the safety testing and process to review safety data, get permission to proceed, etc.

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Asylumdown t1_j5vresc wrote

That’s not necessarily why HIV is hard to make a vaccine for. People can be infected for years without it damaging their immune system to the point where it can no longer mount a defense against HIV. People DO develop robust immune responses to HIV, that’s actually what an HIV+ diagnosis is - positive for HIV antibodies.

Part of the problem is what we think we’re talking about when we say “immune”. Becoming vaccine-immune to something doesn’t mean that none of your cells will ever become infected by that virus, it means that your body will recognize the signs of infection on your cell surfaces and destroy the infected cells before the infection progresses to the point where you’re acutely sick.

The problem is that HIV is incredibly efficient at evading exactly that immune response. It’s not a regular RNA virus that hijacks the entire cell and rapidly reproduces until the cells explode. It’s a retrovirus that transcribes itself right in to your DNA and slowly (relative to something like influenza) buds off new viral particles without immediately killing the cell it’s infected. Your body could be chock-a-block full of HIV antibodies, but if even one viral particle gets through and infects a CD4 cell, there is a high chance it can churn out enough viral particles to produce systemic infection before your immune system notices there’s something amiss with that one specific cell. This is what happens with any infection you have vaccine immunity to - some number of cells will become infected and produce more virus, but in HIV’s case, one of the first places those newly produced viral particles will go are your latent or resting immune cells. These cells won’t immediately begin transcribing any new virus and and HIV writes itself right in to their DNA. It effectively hides itself from the immune system by writing itself in to the DNA of your immune system. That’s also why treatment has to be lifelong. Those latent or resting immune cells can wake up at any time and start the whole thing over again. Some naturally do every day in every human body through the normal functioning of your immune system.

It’s why drugs like PrEP work and vaccines don’t. PrEP, when taken correctly, stops HIV from reproducing at all. So even though some random CD4 cell near the exposure site might become infected, it can never make any new HIV particles and that cell will eventually be cleared from the body through natural processes. It can’t progress to a latent reservoir of infected cells that can permanently hide from the immune system. It’s also why PEP (post exposure prophylaxis) can work, if taken early enough.

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tforss t1_j5xwwnv wrote

HIV is hard to make a vaccine for because without consistent treatment there is no way for the body to fully eradicate it, and it will only progressively get worse. Even with medication, it only suppresses the virus. The body is unable to replicate this protection on its own without the assistance of medication. If a vaccine existed that could stimulate the immune system to produce this defence naturally, it wouldn't have to rely on medication, at least not entirely.

So yes its hard to make a vaccine for something not fully understood and why the immune system cant develop any form of natural resistance. No matter how long someone has been diagnosed as positive, their immune system has no ability to ever learn to protect itself from this.

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Asylumdown t1_j60g0tf wrote

That’s not entirely true. The body does learn to protect itself and it does mount an antibody response and does attack HIV infected cells.

But HIV is one of only three retroviruses that we know about that infect humans and cause disease. The body can’t fully clear any of them. Retroviruses aren’t the only viruses our bodies can’t clear, but the mechanism for why is different from other acute viral infections that hijack your cellular machinery to rapidly print out millions of copies of themselves, killing the host cell in the process. Retroviruses write themselves right in to your DNA and can leave zero trace of themselves on the surface of the cell they’ve infected for weeks, months, or years. Until your own DNA starts transcribing those viral proteins, it’s virtually invisible to your immune system. Once you’re systemically infected with any of the three human retroviruses, some (large) number of cells somewhere in your body will have the instructions to make more of that virus baked in to their biological operating system for the rest of your life. It’s why vaccines don’t work (at least on HIV). Vaccines don’t stop cells from becoming infected. They help your body kill off the infected cells before the infection gets out of control. But with HIV, really any level of active viral replication is “out of control” because it goes straight to places your immune system will never be able to see and immediately hides in cells you will have for the rest of your life.

It sets up a war of attrition that the body has no mechanism to win. With HIV that war involves the very cells the body needs to fight off viral infections, so over time the immune system slowly fails. With the other two retroviruses we can get, they can eventually cause lymphoma.

That said, the medications for HIV are incredibly effective both as a treatment and as a preventative. They completely shut down viral replication. There’s ones that stop HIV from entering a cell at all, one’s that stop it from transcribing itself from RNA in to DNA, one’s that stop it from integrating with your DNA, and ones that stop it from assembling new, functional viral particles. They can’t write it out of the DNA of already infected cells - again, some of which you’ll have for the rest of your life - but they can stop any new cells from becoming infected and keep viable viral particles out of the blood and sexual fluids.

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[deleted] t1_j5vcjf7 wrote

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Still-No-Astronaut t1_j5vkf4g wrote

>It doesn't seem to prevent people from getting sick which is what we were told it would do.

This statement is just incorrect. If you were under the impression that vaccines prevent people from becoming infected, you were mistaken. They prevent hospitalization and death. That has been proven in randomized controlled trials.

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[deleted] t1_j5vkwhg wrote

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[deleted] t1_j5vn07h wrote

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[deleted] t1_j5vqow1 wrote

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Alexis_J_M t1_j5vlh5v wrote

The COVID vaccines have a dramatic difference in the number of people who die, the number of people who get sick enough to go to the hospital, the number of people who are sick long term. That's basic statistics, well understood.

The people dropping dead and having heart problems? Those are statistically insignificant. It's a tragedy when someone drops dead 3 days after their COVID vaccine, but it's not statistically much more likely than people dropping dead for other reasons. Acetaminophen kills more people every year by a wide margin, but you don't hear people talking about banning that.

"Herd Immunity"? The virus is out-mutating that. Just ask all the people who have gotten COVID 3 or 4 times. Just ask the countries that tried that as a national strategy.

It's truly disheartening just how politicized the reaction to COVID-19 has been.

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[deleted] t1_j5vm8pi wrote

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FellowConspirator t1_j5vmicp wrote

Unfortunately, a lot of people have the same confusion, and it's because politically minded people have fostered it. The science and medicine involved aren't so complicated that a layman couldn't grasp it, but unless you seek out the information or rely on expertise and reliable sources, you'd end up where you find yourself.

Ask yourself: is there an empirical way to determine the efficacy of a vaccine? How do vaccines work / what is the mechanism by which they act? Who has this information / where can I find it? Are there populations that are more clinically at risk from infection? What is the mechanism of that? Why do I not know the answer to these questions? Where would I go to find studies and experts in the field?

All of your questions have been asked and have clinical and scientific answers that an unambiguous and with exquisite detail. It's only political if you ignore the science and listen to the pundits and politicians.

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ggiesen t1_j5wpzs8 wrote

We know because we have randomized, double-blind studies and millions upon millions of doses and millions upon millions of infections. We know statistically you're far less likely to end up in the hospital or die from Covid if you're vaccinated, and have millions of examples to prove this out.

That doesn't mean you will never get sick or die from Covid if you're vaccinated, just that you're far less likely to, and as such, the vaccine works. All of these are well understood if you don't bury your head in the sand or fill it with extremist garbage.

Sure, perhaps we've come to expect too much from vaccines, like with the efficacy of things like the polio vaccine which has effectively eradicated the disease. We were all hoping for a silver bullet that can end the pandemic. But that doesn't mean the vaccine doesn't work or that we would be better off without it.

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throaway-90210 t1_j5wvipc wrote

A few things:

  1. We were never guaranteed it would prevent transmission, the original trials were against symptomatic disease. Transmission data was gathered in real time as vaccines were given, and it's an imperfect science anyway. Many vaccines don't stop transmission including the inactivated polio vaccine.

  2. We will always be a step in behind in vaccine updates because of the regulatory process, we updated vaccines to BA.5 and now XBB.1.5 is dominant. It's going to be this way.

  3. It's not an argument, it's a fact it has reduced burden all you have to do is compare hospitalization rates for those vaccines and those not. Unfortunately many people don't understand base rate fallacy.

  4. The increased risk of myocarditis has been acknowledged by every major health body. You know what else causes myocarditis, viruses. The flu can cause it. We know COVID-19 causes it.

  5. The virus will continue to mutate away from immune responses. Herd immunity is definitely not here in the way many people use the term.

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LittleCreepy_ t1_j5uweyj wrote

Well, trying to answer from a different point of view: Vaccines have to help the body kill the intruder, while leaving the patient intakt.

A virus can be understood to undergo different developmental stages. Much like an insekt goes from egg to larvar to adult, a virus goes from virus particle, floating alone and, debatably, dead in their environment, to integrating itself into the host. It quite litteraly overlapes with their victim, the cell becomes, to an extend, two individuals rolled into one. Targetting one while keeping the other is quite the challenge.

I hope I magaged to express myself clearly enough to be understood. I am still trying to put it into words in my native language, so I hope I didnt sow too much confusion. I am open to questions.

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Manuvelo t1_j5wf005 wrote

Damn, now everytime I feel alone I'll remember my Herpes virus is sharing its existence with me.

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LittleCreepy_ t1_j5xzvnb wrote

Jup. We are an ecosystem, with things living not just around and on top of us, but also inside of the very individuals that make up the hive from which the WE/I emerge. There is no seperating line between us and the environment. And if THAT is not freaking you out, I dont know what will.

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Lindseydanger007 t1_j61rsk4 wrote

>irus. You can actually get bit and then go get the vaccine and be saved. That’s part of the reason we can be vaccinated for it. A primed immune system can still have time to react and clear

your explanation was very clear - you did great.

could we kill HIV with radiation in the same way we kill cancer cells? Why isn't that on option - other than obviously radiation isn't ideal in any situation. But would it hypothetically be an option?

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LittleCreepy_ t1_j65cwo2 wrote

Not that I know. Radiation would disproportionatly affekt the genes of the host, rarely getting the genes of the host that both use and very rarely destroying the genes of the virus. The hallmark of a good medizin is that it only targets the parts it should. Radiation is really really reaaaly bad at selectivity.

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0oSlytho0 t1_j5v906w wrote

One other important factor involved is not based on the severity of the disease, nor the targetability of it. It's cost related. Anything that threatens "the west" gets more attention than diseases in e.g. subsaharan Africa because there is more money to make in richer countries.

I work at a company that develops immuno therapies for (initially) late stage (insert type, I can't tell, sorry) cancer. Our antibodies could be designed against basically anything but we picked a target that's not too crowded on the market and affects enough people that we expect to earn back our research investments and make some profit to invest in new therapies.

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TaraJo t1_j5vfm73 wrote

Can I draw attention to the amount of attention thrown at covid, too? When covid came around, the world screeched to a halt and opening up was slow and dangerous until we got a vaccine. Many workplaces, stores, restaurants and other businesses were having to close for weeks at a time because a strain of covid was spreading among their employees. Everyone wanted that vaccine really bad and the sooner the better. HIV, on the other hand, can be (mostly) avoided by practicing safer sex and not sharing needles. It’s much harder to spread and even if you have HIV, you can mostly live your life normally nowadays. There is much less emphasis put on getting an HIV vaccine.

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DrRadon t1_j5vurrk wrote

The main problem with covid actually was that the world did not screech to a halt. I think this grew quit uninterrupted for about three month until lockdowns started to his in Europe and the us. Granted, who could have known and most of us were numbed from media talking about klller viruses ever two or three years…

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TaraJo t1_j5x1kn1 wrote

Things shut down for that first month or so. Not everything but I remember the streets being really creepy with how empty they were. I live along a pretty busy street in my city but there was nobody on the streets for a while.

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tforss t1_j5xtjro wrote

because covid has/had no barriers to who or how it infected the general population and how easily and quickly it spread. HIV doesn't have the same impact to the world population as a whole.

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boooooooooo_cowboys t1_j5vq767 wrote

It’s largely based on whether or not your own immune system is able to clear the virus or not.

Catch measles? Your immune system will kill it and remember it well enough to protect you forever. All you need to do to make a great vaccine is to use killed virus.

If you’re talking herpes or HIV, your immune system can’t root that out and kill it once it’s in there. The only hope of vaccinating is to prevent every last viral particle you encounter from ever being able to enter any of your cells. That’s a much more difficult prospect.

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HighlandHiker t1_j5uh9b8 wrote

I think you’ve hit on some key points with mutations, and but it also is useful to know the gritty mechanics. An antigen is something the body encounters that triggers an immune response, typically but not always a foreign substance or organism. Your body produces antibodies until it finds one that works against the antigen it has encountered, then “saved” that antibody in case it’s useful in the future. Thus, the tetanus vaccine protects against future tetanus infection.

The hard part is finding an antigen the immune system will see and that doesn’t change too quickly over time in our population. Flu changes but slow enough for new vaccines to come out each year (with varying efficacy). Some infections have very clever ways of hiding their antigens from detection, such as disguising as your own cells. Others have potential antigens that are accessible but change very quickly, while other parts of their structure are possible antigens that change slowly over time and make better vaccine targets. The better the infection is at hiding or changing quickly, the harder it is to nail down a good antigen to target.

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abs-licker-69 t1_j5y4gg5 wrote

Making a vaccine is for achievement of introduction of the agent to the body. Body reacts to new, vaccine, agent primarily... which is mild. The subsequent attacks are handled vigorously. As body acts specifically for specific agents, you need to keep in mind how you making the vaccine will affect the receivers. Basically, briefly speaking... vaccine is nothing but part/whole of the disease agent, modified to not make receiver ill but good enough to introduce nd initiate a host defence mechanism. HIV directly targets the immune cells, and turns them into a factory of new infected cells, so to find a safe way to introduce it into a human with controllable outcomes, it'll be a complex process... moreover, HIV is an RNA virus, which means the mutation rate among HIV offsprings is frequent, that mean one vaccine made for a type of virus may/may not be effective against the mutated virus now... Okay this is the simplest i could make it😮‍💨

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KyleRichXV t1_j5x8ac3 wrote

There are a lot of factors. A lot of great stuff here already, but another thing to consider is how well an antibody can “stick” to a piece of the virus to prevent entry into the cell - no entry, no infection. Some viruses have known antigens in that they will produce an immune response when discovered, but the antibodies sticking to that piece of the virus doesn’t actually stop it from binding, or it can bind another receptor.

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