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  • Reply to: Homologous P. vivax malarial recurrences are not necessarily relapses   1 day 15 hours ago

    Genetically, this is a clonal parasite (as opposed to meiotic siblings) explanation for the origin of some or many non-reinfection homologous recurrences of P. vivax malaria.

    The explanation does not apply only to short-term recurrences. This is elucidated in reference 2 in the above blog.

  • Reply to: P. vivax Malaria Recurrence and Human Nature   1 week 2 days ago

    Some students are compiling a list of these literature background-deficient (thus non-authoritative) papers. It might be published.

  • Reply to: Do vaccines increase Malaria and Covid ?   3 weeks 6 days ago

    A study published last week in the Lancet describes alarming shortcomings on vaccines and transmission. The SARS-CoV-2 delta variant is highly transmissible and spreading globally, including in populations with high vaccination rates. Fully vaccinated individuals with breakthrough infections have peak viral load similar to unvaccinated cases and can efficiently transmit infection in household settings, including to fully vaccinated contacts.

    Anika Singanayagam, Seran Hakki, Jake Dunning. Community transmission and viral load kinetics of the SARS-CoV-2 delta (B.1.617.2) variant in vaccinated and unvaccinated individuals in the UK: a prospective, longitudinal, cohort study. Lancet Infect Dis 2021, Oct 29 doi.org/10.1016/

    The US CDC had already raised this alarm in August 2021, but nobody was eager to listen. The CDC report said Delta is highly contagious, likely more severe than other variants and breakthrough infections after vaccination may be as transmissible as for unvaccinated cases.

  • Reply to: NEWS: WHO recommends groundbreaking malaria vaccine for children at risk   1 month 1 week ago

    It is established by now that chloroquine may have contributed to the persistence of malaria in many countries. This drug is still of large use in tropical countries where ACT antimalaria drugs are too expensive. A 5-fold increase in gametocytogenesis in Plasmodium falciparum has been documented. And this renders malaria eradication by other means illusory.

               Buckling A, Read AF. Chloroquine increases Plasmodium falciparum gametocytogenesis in vitro. Parasitology, 1999, 118, 339-46

    The situation also appears to be disastrous for mefloquine monotherapy. Patients treated with mefloquine had a high risk for mosquito infectivity and transmissibility. A disaster is pending for Africa. Lariam is now forbidden in several European countries and remaining stocks are sold in Africa.

             Akintunde Sowunmi, Oluchi O Nkogho , Effects of mefloquine and artesunate mefloquine on the emergence, clearance and sex ratio of Plasmodium falciparum gametocytes in malarious children. Malar J. 2009; 8: 297.

    The situation is as dramatic for the RTS,S vaccine which protects only against sporozoites but does not induce clinical immunity against blood-stage parasites. The vaccine showed evidence of 35,9% efficacy in the first year after vaccination, but efficacy fell to 2.5% in the fourth year. The cohort with a high exposure index even showed a negative efficacy during the fifth year(i.e. a higher infection rate).

            A Olutu, G Fegan, P Bejon. Seven-year efficacy of RTS, S/AS01 malaria vaccine amoung young African children. NEJM, 2016, 374, 2519-2529

    Naturally acquired or vaccine injected antibodies do not confer sterile immunity and the mechanisms of action are still unclear. Most studies have focused on the inhibitory effect of antibodies, but a recent paper from Uganda reviews both the beneficial as well as the potentially harmful roles of naturally acquired antibodies, as well as autoantibodies formed in malaria

            Tijani, M.K.; Lugaajju, A.; Persson, K.E.M. Naturally Acquired Antibodies against Plasmodium falciparum: Friend or Foe? Pathogens 2021, 10, 832. https://doi.org/10.3390/pathogens10070832

    Another recent study discovered blocking antibodies. They are not inhibitory but interfere with inhibitory antibody activity by competing for binding to the merozoite surface. This suggests an immune evasion mechanism to avoid the action of protective antibodies. The importance of inhibitory antibodies for the clinical outcome of infection and the development of vaccines will need to be analyzed in a larger longitudinal study.   

         Roseangela I. Nwuba, Olugbemiro Sodeinde, Chiaka I. Anumudu, Yusuf O. Omosun, Alexander B. Odaibo, Anthony A. Holder. The Human Immune Response to Plasmodium falciparum Includes Both Antibodies That Inhibit Merozoite Surface Protein 1 Secondary Processing and Blocking Antibodies . ASM Journals.  Infection and Immunity.  2020 Vol. 70, No. 9 DOI: https://doi.org/10.1128/IAI.70.9.5328-5331.2002

    These inhibitory antibodies had also been found in malaria-exposed Kenyan children and adults. The findings of that study suggest that variation in invasion phenotype might have evolved as a mechanism that facilitates immune evasion by Plasmodium falciparum

          Persson KE, McCallum FJ, Reiling L, Lister NA, Stubbs J, Cowman AF, Marsh K, Beeson JG. Variation in use of erythrocyte invasion pathways by Plasmodium falciparum mediates evasion of human inhibitory antibodies. J Clin Invest. 2008 Jan;118(1):342-51. doi: 10.1172/JCI32138.

    The invasion of red blood cells (RBC) by merozoites is a target for vaccine development. Although anti-merozoite antibodies can block invasion in vitro, there is no efficacy in vivo. A study found that a monoclonal antibody directed against the merozoite and human polyclonal IgG from merozoite vaccine recipients enhanced RBC invasion. These results demonstrate, contrary to current views, that complement activation in conjunction with antibodies can paradoxically aid parasites invade RBCs and should be considered in future design and testing of merozoite vaccines.

            Biryukov S, Angov E, Landmesser ME, Spring MD, Ockenhouse CF, Stoute JA. Complement and Antibody-mediated Enhancement of Red Blood Cell Invasion and Growth of Malaria Parasites. EBioMedicine. 2016 Jul;9:207-216. doi: 10.1016/j.ebiom.2016.05.015. Epub 2016 May 14. PMID: 27333049; PMCID: PMC4972486.

    If antibodies introduced by a vaccine can enhance the growth of parasites, this is an efficient way for parasites to avoid getting cleared by the human immune system.

  • Reply to: NEWS: WHO recommends groundbreaking malaria vaccine for children at risk   1 month 2 weeks ago

    The deafening media noise and tam-tam made by WHO-GSK-Gates on a new malaria vaccine for African children is alarming. It is claimed that it has a preventive efficacy of 35%, which in fact is similar to results of previous trials as documented in the film Malaria Business by Bernard Crutzen in 2016. 35% efficacy of a vaccine on Africans living in malaria endemic countries is almost meaningless. Natural immunity gained after multiple infections is probably much higher.

    Peer reviewed papers even find that the efficacy vanishes with time and ultimately increases the number of infected children. The scientific literature also describes severe  side effects.                             

    Clinical trials run by Africans in several countries have shown that the prophylactic activity of Artemisia afra infusions is extraordinary. In schools and communities where children drink several cups of Artemisia infusions per week malaria completely disappeared. More important, the infusion not only acts on sporozoites and merozoites but also on gametocytes, which are radically eliminated. Without transmission eradication becomes possible.

    More research work should be devoted on the prophylactic effect of herbal medicine. Some recent papers indicate that the lysine content of the Artemisia plant might play a key role.

        Meireles P, Brás D, Fontinha D, Chora ÂF, Serre K, Mendes AM, Prudêncio M. Elimination of Hepatic Rodent Plasmodium Parasites by Amino Acid Supplementation. iScience. 2020 Nov 6;23(12):101781. doi: 10.1016/j.isci.2020.101781.

        Lutgen P. Prophylaxis of malaria by Artemisia infusions: The key role of lysine. Pharm Pharmacol Int J. 2021;9(5):210‒211. DOI: 10.15406/ppij.2021.09.00346

    And as doctor Jerôme Munyangi stated last week : « L’histoire de la médecine africaine sera écrite par les Africains »