Malevolent Designer News - What a Devilishly Good Job Creationism's Divine Malevolence Made of Malaria!

This false-colored electron micrograph shows a sporozoite of Plasmodium bergei migrating through the cytoplasm of midgut epithelia of an Anopheles stephensi mosquito.

© Ute Frevert/Margaret Shear/Wikipedia

Why vaccination against malaria quickly loses its protective effect

Scientists in Germany have worked out why immunity to malaria is not very effective and has a very short duration.

Malaria is one of the world's biggest killers. It is caused by a number of different, closely related Plasmodium parasites, normally transmitted by Anopheles mosquitos. The commonest parasite is Plasmodium falciparum and the most efficient vector is Anopheles gambiae. According to the US Center for Disease Control (CDC):

Malaria is one of the most severe public health problems worldwide. It is a leading cause of death and disease in many developing countries, where young children and pregnant women are the groups most affected. According to the 2021 World Malaria Report:

• Nearly half the world’s population lives in areas at risk of malaria transmission in 87 countries and territories.
• In 2020, malaria caused an estimated 241 million clinical episodes, and 627,000 deaths. An estimated 95% of deaths in 2020 were in the WHO African Region.

Now Scientists from the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) who studied the human immune response after immunization with the malaria pathogen Plasmodium falciparum have discovered that the immune response has a very short duration. They concluded:

This could explain why natural infections, to which people in endemic areas are constantly exposed, offer little protection against new diseases with other strains, and why the effect of the vaccination available to date lasts only a short time.

Creationist mode:

But, as any creationist will tell you, this is not a matter of chance or even a natural process such as evolution. It was the work of a magic designer who deliberately created the malaria parasites to do what they do and included the ability to overcome the human immune response which it also designed to protect us from the organisms it designs to harm us. Don't laugh; this is actually what an intelligent [sic] design creationist must believe because they believe everything is the work of a single designer!

Creationist mode:

According to information supplied in the DKFZ news release:

[The researchers] goal was to find out against which protein components the T helper cells induced in this way are directed. To the researchers' surprise, the T helper cells reacted exclusively to the protein sequence of the vaccine strain and showed hardly any cross-reactivity with the naturally occurring pathogen variants.

It goes on to explain:

Despite impressive successes in controlling malaria, more than 600,000 people worldwide still die from the tropical disease every year, according to the World Health Organization. The vast majority of fatal cases of malaria are caused by the pathogen Plasmodium falciparum. To date, there is only one approved vaccine against this single-celled organism, and its efficacy, which is already rather low, does not last long.

The specificity of the T-cell clones prevents the constantly recurring natural infections with the pathogen from acting as a natural 'booster.' This could possibly explain why the protective effect of the malaria vaccine wears off so quickly.

To improve the vaccine, we need to understand which protective antibodies are induced by the immunization. But the production of such antibodies depends to a large extent on help from the so-called follicular T helper cells. They ensure that B cells transform into antibody-producing plasma cells and memory B cells.

"The receptors highly specifically bind only the CSP epitopes of the vaccine strain used. Even deviations of only a single amino acid component were not tolerated in some cases.

Hedda Wardemann, Corresponding author
Division of B Cell Immunology
German Cancer Research Center, Heidelberg, Germany.

The vaccine is directed against CSP, the quantitatively dominant protein on the surface of the "sporozoites". Sporozoites are the stage of the malaria pathogen which is transmitted with the bite of the mosquito and enters human blood.

To study the T helper cell response against CSP in detail, the team led by DKFZ immunologist Wardemann examined the blood of volunteers infected with killed P. falciparum sporozoites from the vaccine strain. The volunteers were of European descent and had no prior contact with malaria pathogens. The researchers analyzed the induced Plasmodium-specific follicular T helper cells at the single cell level. In particular, they focused their investigation on which sequences of CSP are recognized by the receptors of the T helper cells.

The analyses revealed that the T-cell receptors mainly targeted amino acids 311 to 333 of the CSP. But another observation stunned the researchers: there was virtually no cross-reactivity between the individual T-cell clones.

The immunologist points out that in the natural population of P. falciparum, sequence polymorphisms occur to a high degree in this region of the CSP. The researcher recommends that further development of the vaccine should test whether inducing a broader spectrum of T helper cells could generate longer-lasting immune protection.

In their published paper in Science Immunology, the DKFZ researchers say:

Malaria vaccine helper

Experimental vaccination with Plasmodium falciparum (Pf) sporozoites (PfSPZ) can induce immune responses that limit the transmission of Pf sporozoites to humans upon the bite of a Pf-infected mosquito. Wahl et al. carried out functional TCR repertoire studies in circulating T follicular helper (cT_FH) cells at the single-cell level to understand how this subset contributes to protective immunity. Repeated vaccination with PfSPZ induced a dynamic and polyclonal cT_FH response in which a large fraction of cells responded to a small subset of epitopes from the Pf circumsporozoite protein (PfCSP). A T cell supertope was identified as amino acids 311 to 333 in the Th2R/T* region presented by HLA-DR molecules. TCRs recognizing this region were sensitive to parasite sequence variations, providing insight as to why cT_FH specific to nonvaccine strains may not support protective responses.

Abstract

T follicular helper (T_FH) cells play a crucial role in the development of long-lived, high-quality B cell responses after infection and vaccination. However, little is known about how antigen-specific T_FH cells clonally evolve in response to complex pathogens and what guides the targeting of different epitopes. Here, we assessed the cell phenotype, clonal dynamics, and T cell receptor (TCR) specificity of human circulating T_FH (cT_FH) cells during successive malaria immunizations with radiation-attenuated Plasmodium falciparum (Pf) sporozoites. Repeated parasite exposures induced a dynamic, polyclonal cT_FH response with high frequency of cells specific to a small number of epitopes in Pf circumsporozoite protein (PfCSP), the primary sporozoite surface protein and well-defined vaccine target. Human leukocyte antigen (HLA) restrictions and differences in TCR generation probability were associated with differences in the epitope targeting frequency and indicated the potential of amino acids 311 to 333 in the Th2R/T* region as a T cell supertope. But most of vaccine-induced anti–amino acid 311 to 333 TCRs, including convergent TCRs with high sequence similarity, failed to tolerate natural polymorphisms in their target peptide sequence, thus demonstrating that the T_FH cell response was limited to the vaccine strain. These data suggest that the high parasite diversity in endemic areas will limit boosting of the vaccine-induced T_FH cell response by natural infections. Our findings may guide the further design of PfCSP-based malaria vaccines able to induce potent T helper cell responses for broad, long-lasting antibody responses.

Wahl, Ilka; Obraztsova, Anna S.; Puchan, Julia; Hundsdorfer, Rebecca; Chakravarty, Sumana; Sim B. Kim, Lee; Hoffman, Stephen L.; Kremsner, Peter G.; Mordmüller, Benjamin; Wardemann, Hedda
Clonal evolution and TCR specificity of the human T_FH cell response to Plasmodium falciparum CSP
Science Immunology 2022 7(72); DOI: 10.1126/sciimmunol.abm9644

© 2022The Authors
Published by American Association for the Advancement of Science.
Reprinted by kind permission under licence #5334151458134

What this means is that immunity, whether induced by vaccine or by infection, is effective against a highly specific sequence of amino acids on the parasite that is not conserved, so any mutation renders this sequence invisible to the T cells. In other words, the parasite can quickly evade immunity with a simple mutation in part of its genome that is not essential to its survival. A simple evolutionary change means it can continue to live and reproduce in its hosts from which earlier forms may have been removed, so removing any competition.

ID advocates are obliged by dogma to insist that this can't all be by chance and the operation of natural laws of physics and chemistry but must be the intended outcome of an omniscient designer.

Followers of the leading intelligent [sic] design advocate and Deception Institute functionary, Michael J Behe, may recall how he wrote a best-selling book, widely admired by scientifically illiterate creationists but slated by mainstream biologists, in which he cited the development of resistance to antimalarial drugs as an example of 'irreducible complexity' and so evidence for design. His argument was blown to pieces by evolutionary biologist, Professor Kenneth Miller.

Professor Miller pointed out how it was based on a misrepresentation of statistical probabilities as they relate to evolution, which Behe’s mathematical model had assumed evolutionary biologists thought took place in a single cell as a single process, and not an accumulative event in a population over time, so produced a conveniently high degree of improbability, and the demonstrably false claim that there could only be one pathway to its evolution. But what Behe failed to point out to his target audience was that, even if his argument had had any merit, it would mean their favourite designer, i.e. the Christian god, was actively working to prevent human medical science save the lives of millions of children in Africa and other malaria-prone parts of the world from a parasite that it had designed for the purpose of killing them.

For some inexplicable reason, creationists prefer to present their favourite god as a malevolent monster who actively tries to kill children with a parasite rather than have people accept that a better, blame-free explanation is to be found in a well-attested, mindless natural process - evolution by natural selection.

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