The dynamics of naturally acquired immune responses to Plasmodium falciparum sexual stage antigens Pfs230 & Pfs48/45 in a low endemic area in Tanzania

PLoS One. 2010 Nov 29;5(11):e14114. doi: 10.1371/journal.pone.0014114.


Background: Naturally acquired immune responses against sexual stages of P. falciparum can reduce the transmission of malaria from humans to mosquitoes. These antigens are candidate transmission-blocking vaccines but little is known about the acquisition of sexual stage immunity after exposure to gametocytes, or their longevity and functionality. We conducted a longitudinal study on functional sexual stage immune responses.

Methodology/principal findings: Parasitaemic individuals (n = 116) were recruited at a health centre in Lower Moshi, Tanzania. Patients presented with gametocytes (n = 16), developed circulating gametocytes by day 7 (n = 69) or between day 7 and 14 (n = 10) after treatment or did not develop gametocytes (n = 21). Serum samples were collected on the first day of gametocytaemia and 28 and 84 days post-enrolment (or d7, 28, 84 after enrolment from gametocyte-negative individuals). Antibody responses to sexual stage antigens Pfs230 and Pfs48/45 were detected in 20.7% (72/348) and 15.2% (53/348) of the samples, respectively, and were less prevalent than antibodies against asexual stage antigens MSP-1(19) (48.1%; 137/285) and AMA-1 (52.4%; 129/246)(p<0.001). The prevalence of anti-Pfs230 (p = 0.026) and anti-Pfs48/45 antibodies (p = 0.017) increased with longer duration of gametocyte exposure and had an estimated half-life of approximately 3 months. Membrane feeding experiments demonstrated a strong association between the prevalence and concentration of Pfs230 and Pfs48/45 antibodies and transmission reducing activity (TRA, p<0.01).

Conclusions/significance: In a longitudinal study, anti-Pfs230 and Pfs48/45 antibodies developed rapidly after exposure to gametocytes and were strongly associated with transmission-reducing activity. Our data indicate that the extent of antigen exposure is important in eliciting functional transmission-reducing immune responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Antibodies, Protozoan / blood
  • Antibodies, Protozoan / immunology
  • Antigens, Protozoan / immunology*
  • Child
  • Child, Preschool
  • Endemic Diseases
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Longitudinal Studies
  • Malaria, Falciparum / epidemiology
  • Malaria, Falciparum / immunology*
  • Male
  • Membrane Glycoproteins / immunology*
  • Middle Aged
  • Plasmodium falciparum / immunology*
  • Protozoan Proteins / immunology*
  • Tanzania / epidemiology
  • Time Factors
  • Young Adult


  • Antibodies, Protozoan
  • Antigens, Protozoan
  • Membrane Glycoproteins
  • Pfs230 antigen, Plasmodium falciparum
  • Protozoan Proteins
  • pfs48-45 protein, Plasmodium falciparum