Smallpox and AIDS?

Components of a smallpox vaccination kit (image in the public domain).

The smartest person with whom I have ever worked sent me a very interesting article from Science Daily. She and I wrote several articles related to the science behind vaccination years ago, and this article is relevant to that issue. It reports on a study published in BMC Immunology, an open-access journal. The results of the study are worth noting.

The researchers studied peripheral blood mononuclear cells (PBMCs) and how susceptible they were to infection by HIV, the virus that causes AIDS. PBMC is the name given to any blood cell that has a round nucleus. Since red blood cells don’t have a nucleus, what this means is that the researchers were looking at certain white blood cells, which are a part of the body’s immune system. Obviously, the susceptibility of white blood cells to HIV is an important issue in the study of AIDS.

Here is the key: they looked at the PBMCs from 10 volunteers who had never been vaccinated against smallpox as well as the PBMCs from 10 volunteers who had been vaccinated against smallpox with a Vaccinia-based vaccine 3 to 6 months prior to the study. Vaccinia is a virus in the poxvirus family that is typically used to produce the immune response to protect against smallpox. Guess what they found.

They found that the PBMCs from people who had recently been given the Vaccinia-based vaccine were significantly less prone to infection than those from the people who had never been given the vaccine. In other words, the white blood cells from people who were recently vaccinated against smallpox were more resistant to HIV infection than those who had never been given the vaccine!

Now why in the world would a vaccination against smallpox make white blood cells more resistant to HIV? Well, according to the authors, it has been previously shown that when a person is infected with the virus that causes measles, for example, his or her white blood cells are also resistant to HIV infection. They think this occurs because the other virus is more easily detected by the immune system, and that “primes” the immune system to start dealing with infections. As a result, a virus that is not easily detected by the body (like HIV) gets attacked because the immune system has already been kicked into high gear by the other virus.

Of course, the article in Science Daily and the research article say that these results might explain the sudden explosion of AIDS cases that started in Africa in the mid-to-late 1950s. As the Science Daily article quotes an author of the study:

There have been several proposed explanations for the rapid spread of HIV in Africa…Our finding that prior immunization with vaccinia virus may provide an individual with some degree of protection to subsequent HIV infection suggests that the withdrawal of such vaccination may be a partial explanation.

So in other words, once smallpox was eradicated, routine vaccination went away. As a result, people’s immune systems weren’t being “primed” by the Vaccinia virus that is a part of the smallpox vaccine, and this led to a significant rise in AIDS cases. It is an interesting conclusion, and I think the study provides evidence for it.

However, I have a word of caution: Don’t think that we can start vaccinating people against smallpox and that will somehow reduce the spread of AIDS. First, what happens in a Petri dish is not always indicative of what happens in the body. Thus, just because some cells taken from people were resistant to HIV in a controlled laboratory setting doesn’t mean they will behave the same inside a person.

Second, there are risks associated with smallpox vaccination, as there are with any medical treatment. In order for the risks to be worth taking, the benefits have to be significant. When smallpox is a viable threat, the benefits of smallpox vaccination far exceed the risks, so getting the smallpox vaccine is clearly the best course of action. However, this study has no way of measuring the actual amount of protection the smallpox vaccine might provide against AIDS. Thus, the benefits are completely unknown. Until we can quantify exactly what level of protection is given (if any) by the smallpox vaccine, there is just no medically justifiable reason to start vaccinating against smallpox when smallpox itself isn’t a danger.

So while this study offers no immediate help in the fight against AIDS, it gives us some interesting new avenues to pursue. After all, if the measles virus and the Vaccinia virus really do give some level of protection against AIDS, we should be able to find the commonalities between those viruses (as well as other viruses that do the same). Those commonalities might help us produce an effective vaccination that specifically protects against HIV.

10 thoughts on “Smallpox and AIDS?”

  1. I’m very happy to learn that you aren’t an AIDS denialist. And not an anti-vaxer as well. However, this statement needs revising:

    “Second, there are risks associated with smallpox vaccination, as there are with any medical treatment. In order for the risks to be worth taking, the benefits have to be significant.”

    Change the last word to “larger than the risks”. Since the risks associated with smallpox vaccination are very, very low, then it should be administered as a public health measure if the benefits are merely very low. I’m afraid the actual dollars and cents cost of a full smallpox vaccination regime is what will prevent it from happening in Africa.

    1. Shooter, I follow the data. That seems to be something you can’t understand. The evidence for the efficacy of vaccination is overwhelming, and while there are some puzzles associated with HIV and AIDS, Koch’s postulates have been fulfilled in regards to HIV, so it clearly causes AIDS. If you would only follow the data instead of your high priests, you would understand.

      By the way, the risks associated with the smallpox vaccine are not “very, very low.” As the data clearly indicate, the serious side effect rate for the smallpox vaccine is about 0.1%, and the life-threatening side effect rate is about 0.001%-0.005%. Compare this to the MMR, where the serious side effect rate is 1,000 times lower and the life-threatening side effect rate is so low it cannot be quantified.

      I guess we need to add vaccines to the list of things you know very little about. The list just keeps growing, doesn’t it?

  2. We are not comparing smallpox vaccine to MMR vaccine. We are stating the risks associated with smallpox vaccine. 1 in every 1,000 people experience “serious” reactions. Specifically:

    “These reactions included a toxic or allergic reaction at the site of the vaccination (erythema multiforme), spread of the vaccinia virus to other parts of the body and to other individuals (inadvertent inoculation), and spread of the vaccinia virus to other parts of the body through the blood (generalized vaccinia). These types of reactions may require medical attention.”

    1 in 1,000 people may require medical attention. That’s low in my book. How about morbidity:

    “Based on past experience, it is estimated that 1 or 2 people in 1 million who receive the vaccine may die as a result.”

    Again may die. So it’s safe to say less than 1 in 1 million have died from smallpox vaccination. That’s very low. (see, I’m compromising by taking one “very” off)

    So my point – which you didn’t address — is that the benefit of smallpox vaccination need only be greater than this very small risk. If further research validates and confirms this study’s findings, then smallpox vaccination should be disseminated as widely as possible in sub-Saharan Africa. Do you agree?

    1. Shooter, you really need to learn about things before you try to pontificate on them. Of course, what am I thinking? If you learned about these things, it would destroy your preconceived notions, and we can’t have that, can we?

      We are INDEED comparing the smallpox vaccine to routine vaccines, as it gives a very strong indicator of what a low risk is. You claim (erroneously) that the risks of the smallpox vaccine are “very, very low.” The risks of the MMR vaccine are very, very low, and as the data clearly show, the risks of the smallpox vaccine are 1,000 times higher. Thus, the risks of the smallpox vaccine are definitely NOT very, very low. They are not even “very low.”

      Since you seem to follow the statements of high priests better than you do the data, perhaps the World Health Organization’s statements on the smallpox vaccine will help you come to the same conclusion that anyone who understands the data has already come to:

      Existing vaccines have proven efficacy but also have a HIGH INCIDENCE of adverse side-effects.

      The risk of adverse events is SUFFICIENTLY HIGH that vaccination is not warranted if there is no or little real risk of exposure.

      Vaccine administration is warranted in individuals exposed to the virus or facing a real risk of exposure (see above).

      (emphasis mine)

      Of course, if the World Health Organization isn’t high enough in your church hierarchy, perhaps your favorite source will convince you:

      As of June 21, 2003, a scientific advisory panel had issued a recommendation against further vaccination of first responders because a SIGNIFICANT number of those vaccinated suffered heart problems, notably pericarditis and myocarditis.

      In May 2007, the Vaccines and Related Biological Products Advisory Committee of the U.S. Food and Drug Administration (FDA) voted unanimously that a new live virus vaccine produced by Acambis, ACAM2000, is both safe and effective for use in persons at high risk of exposure to smallpox virus. However, due to the HIGH RATE OF SERIOUS ADVERSE EFFECTS, the vaccine will only be made available to the CDC (a part of the United States Department of Health and Human Services) for the Strategic National Stockpile.

      (emphasis mine)

      You ask, “If further research validates and confirms this study’s findings, then smallpox vaccination should be disseminated as widely as possible in sub-Saharan Africa. Do you agree?” Of course not, and no responsible scientist could possibly agree with such an ignorant statement. If further research validates and confirms this study’s findings, then the LEVEL OF PROTECTION must be assessed. If the level of protection provides a benefit that is significantly greater than the (not small) risk associated with the smallpox vaccine, THEN AND ONLY THEN should the smallpox vaccine be used as a preventative measure against HIV. Even if this becomes the case, it should be done according to RESPONSIBLE medical practice, which is to start with the high-risk groups and see how they respond before doing anything with widespread dissemination. BOY am I glad you aren’t in the medical field!

  3. “I’m afraid the actual dollars and cents cost of a full smallpox vaccination regime is what will prevent it from happening in Africa.”

    Unfortunately Dollars and cents are very important, Shooter. There’s only a certain amount that’s going to be spent on healthcare in Africa. I know the sentiment that asks “for the sake of what money would you surrender a human life?” But when you consider instead “for how many other lives (which could be saved with that same money) would you surrender a human life?” things look slightly different.

    Let’s say you can either provide, for a certain amount of money, mosquito nets which are proven very effective at stopping the terrible scourge of Malaria (Malaria remains among the biggest killers here an SS Africa), or vaccines for a different disease which has an unknown measure of protection against AIDS (and has side affects). Or you could provide propper wells and toilets in combat against water-borne diseases such as Cholera and Dysentry.

    1. Josiah, your comments are so thoughtful. They are a breath of fresh air! You have elucidated the considerations of reasonable medical professionals exceptionally well! Indeed, the consideration of “dollars and cents” is very important, and anyone with any sense (pun intended) understands that you spend your relief money where it can do the most good.

  4. Josiah, I’m with you. Malaria, cholera and dysentery should get the cash right now. Smallpox vaccinations as an anti-AIDS measure is a long way from even being a legitimate option right now. Long way to go to prove its effectiveness and then there is the relative cost issue you bring up. I’m not calling for everybody in Africa to get the smallpox vaccine right now.

    Dr. Jay, I’m against you, again. All this talk of low, high, risky, incidence, significant, etc. is relative. If I say the risk of dying in an airplane crash is very low, you could just say dying by lightning strike is really, really low. Does that somehow make flying in an airplane risky, in absolute terms? Of course not. Your comparison to MMR is a poor rhetorical trick.

    In the Wikipedia example, the FDA didn’t just measure the number and level of side effects and declare it use to be forbidden or universally required, but weighed these risks against the benefits provided. In this case, the benefits of using the vaccine only in case of a smallpox outbreak outweighed the risks. The benefits of providing vaccination for all first responders as a matter of course did not however outweigh the risks.

    I agree with all of your last paragraph, except “significantly greater”. That is my original point. The benefits only have to be slightly greater than the risks to advocate for the measure being proposed. And of course risk / benefit analysis isn’t perfect, so you might build in a margin of error for the benefit to exceed the risk, but “significantly greater” does not explain this practice at all.

    1. Sorry, Shooter, but you are dead wrong (for the millionth time or so). I am surprised that you are arguing against the high priests, but I assume that means this is not a dogma issue for you. Of course the smallpox vaccine is a high-risk vaccine. That’s why WHO says it has a “HIGH INCIDENCE of adverse side-effects.” Of course it is not a rhetorical trick to compare it to the MMR vaccine. The MMR vaccine is established as a very-low-risk vaccine. Given that the rate of serious side effects is 1,000x greater for the smallpox vaccine, it is clear that the smallpox vaccine is NOT a low-risk vaccine.

      In the Wikipedia article, it says “a SIGNIFICANT number of those vaccinated suffered heart problems, notably pericarditis and myocarditis.” When a significant number of serious side effects occur, the vaccine is definitely NOT low-risk. Note what else your favorite source says in the same article:

      …making vaccination against smallpox with vaccinia the most dangerous immunisation widely provided in modern times

      Clearly, then, it is NOT a low-risk vaccine.

      Your original point is still dead wrong, because you cannot be bothered to educate yourself before trying to pontificate. I know thinking isn’t your strong suit, but bear with me here. When you immunize a population, you are immunizing people who would normally never get the disease. Thus, you are exposing a LARGE population to the side effect in order to protect a SMALLER population against the disease. Thus, the benefit must be SIGNIFICANTLY greater than the risk, since the risk is spread over a larger population than the benefit.

    1. “Is getting in a high speed head-on collision in the world’s safest car safe?”
      Of course not.

      However, trying to distract from the fact that you are wrong is not safe, either, at least not on this blog. Just to remind you, the data clearly show that the smallpox vaccine is not a “very, very low” risk vaccine. Instead, it carries a risk that both WHO and Wikipedia say is SIGNIFICANT. In addition, reasonable medical scientists understand that the benefits of ANY preventative measure have to be SIGNIFICANTLY greater than the risks. Otherwise, widespread use of the preventative measure is not justified. So in this post, you have been demonstrated to be wrong on two counts.

      Actually, for you, being wrong only twice in one post is an improvement…

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