P4 - Combined Effects of RTS,S Vaccination and PBO Nets on Plasmodium Infection and Transmission

1) to describe the impact of the RTS,s malaria vaccine on P. falciparum infection and transmission,

2) to assess the impact of PBO nets on exposure to malaria infection and transmission

3) to determine the combined effects of the RTS,S vaccine and PBO nets on the incidence and transmission of Plasmodium infection

We compared the incidence and transmission of malaria infection in an area with two interventions (RTS,S vaccine and PBO nets) to an area without either intervention.

In 200 of our study households, we are systematically collecting mosquitoes and measuring
  • Force of infection
  • Anopheles sporozoite rates
  • Anopeheles gravidity status
  • Anopheles species abundance

We compared findings in houses with the new PBO nets to those in houses with conventional nets.

The WHO pilot implementation will target 240,000 Malawian children and will focus on

  • Feasibility
  • Hospital surveillance
  • Impact on all-cause childhood mortality


Our ICEMR is well positioned to examine the impact on malaria infection and transmission in more detail. We studied children eligible to receive the vaccine (n= 773) and their siblings (n=713) via active case detection (every 2 months) and passive case detection over a total of six



Peter Ntenda M.D., Ph.D. 
 Associate Professor 
Department of Osteopathic
College of Medicine

Don Mathanga M.D., Ph.D.  
Director of the COM-MACCDAC
Associate Professor
College of Medicine

Study Team

Miriam Laufer, M.D., MPH
Center for Vaccine Development and Global Health
University of Maryland

Lauren Cohee, M.D., M.Sc.
Center for Vaccine Development and Global Health
University of Maryland

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Themba Mzilahowa, Ph.D.
Associate Professor
College of Medicine

Clarissa Valim, M.D., Sc.D.
Project Leader
Research Associate Professor
Department of Global Health
Boston University School of Public Health

Project Location

  • Machinga
  • Balaka



Project Publications

  1. Agnandji ST, Lell B, Soulanoudjingar SS, et al. First results of phase 3 trial of RTS,S/AS01 malaria vaccine in African children. N Engl J Med. 2011;365(20):1863-1875. doi:10.1056/NEJMoa1102287.

  2. Buchwald AG, Coalson JE, Cohee LM, et al. Insecticide-treated net effectiveness at preventing Plasmodium falciparum infection varies by age and season. Malar J. 2017;16(1):32. doi:10.1186/s12936-017-1686-2.

  3. Buchwald AG, Sixpence A, Chimenya M, Damson M, Sorkin JD, Wilson ML, Seydel K, Hochman S, Mathanga DP, Taylor TE LM. Clinical implications of asymptomatic Plasmodium falciparum infections in Malawi. Clin Infect Dis. 2018;10(1093).

  4. Kazembe LN, Kleinschmidt I, Holtz TH, Sharp BL. Spatial analysis and mapping of malaria risk in Malawi using point-referenced prevalence of infection data. International journal of health geographics. 2006;5:41.

  5. Lindblade KA, Mwandama D, Mzilahowa T, Steinhardt L, Gimnig J, Shah M, et al. A cohort study of the effectiveness of insecticide-treated bed nets to prevent malaria in an area of moderate pyrethroid resistance, Malawi. Malaria journal. 2015;14:31.

  6. Mathanga DP, Mwandama DA, Bauleni A, et al. The effectiveness of long-lasting, insecticide-treated nets in a setting of pyrethroid resistance: a case-control study among febrile children 6 to 59 months of age in Machinga District, Malawi. Malar J. 2015;14:457. doi:10.1186/s12936-015-0961-3.

  7. Ministry of Health (MoH). National Malaria Control Programme - NMCP/Malawi and ICF. 2018. Lilongwe, Malawi, and Rockville, Maryland UN and I. Malawi Malaria Indicator Survey 2017.

  8. Mzilahowa T, Ball AJ, Bass C, Morgan JC, Nyoni B, Steen K, et al. Reduced susceptibility to DDT in field populations of Anopheles quadriannulatus and Anopheles arabiensis in Malawi: evidence for larval selection. Medical and veterinary entomology. 2008;22(3):258-63.

  9. Mzilahowa T, Chiumia M, Mbewe RB, et al. Increasing insecticide resistance in Anopheles funestus and Anopheles arabiensis in Malawi, 2011-2015. Malar J. 2016;15(1):563. doi:10.1186/s12936-016-1610-1.

  10. Ochomo EO, Bayoh NM, Walker ED, et al. The efficacy of long-lasting nets with declining physical integrity may be compromised in areas with high levels of pyrethroid resistance. Malar J. 2013;12(1):1. doi:10.1186/1475-2875-12-368.

  11. Okiro EA, Kazembe LN, Kabaria CW, Ligomeka J, Noor AM, Ali D, et al. Childhood malaria admission rates to four hospitals in Malawi between 2000 and 2010. PloS one. 2013;8(4):e62214.

  12. Protopopoff N, Mosha JF, Lukole E, et al. Effectiveness of a long-lasting piperonyl butoxide-treated insecticidal net and indoor residual spray interventions, separately and together, against malaria transmitted by pyrethroid-resistant mosquitoes: a cluster, randomised controlled, two-by-two fact. Lancet. 2018;391(10130):1577-1588. doi:10.1016/S0140-6736(18)30427-6.

  13. Roca-Feltrer A, Kwizombe CJ, Sanjoaquin MA, Sesay SS, Faragher B, Harrison J, et al. Lack of decline in childhood malaria, Malawi, 2001-2010. Emerging infectious diseases. 2012;18(2):272-8.

  14. Sisya TJ, Kamn'gona RM, Vareta JA, Fulakeza JM, Mukaka MF, Seydel KB, et al. Subtle changes in Plasmodium falciparum infection complexity following enhanced intervention in Malawi. Acta tropica. 2015;142:108-14.