I trained in medicine at Cambridge and Oxford, and worked as a clinician in medicine, paediatrics, and general practice in the UK and Africa before more formal research training with an MSc in Epidemiology at the London School of Hygiene and Tropical Medicine. I have undertaken research in the National Perinatal Epidemiology Unit, Oxford, the Oxford Vaccine Group, Oxford, the Kenya Medical Research Unit, Kilifi, Kenya, the Medical Research Council Unit, The Gambia, the Malawi-Liverpool-Wellcome Trust Research Programme, Blantyre, Malawi and two periods of time working with Professor Martin Maiden in the Department of Zoology, Oxford, where I am currently a senior researcher.
The main focus of my research has been in vaccination against meningococcal disease, immunological memory, risk factors for carriage and transmission of Neisseria meningitidis, and the effects of vaccination on carriage. I am also interested in the role of non-pathogenic Neisseria species in the development of natural immunity against Neisseria meningitidis. Other research interests include understanding transmission and immunity against Non-typhoidal salmonella.
PT Heath, JM MacLennan, ER Moxon. (1998) Polio vaccine: is it time for a change? Archives of Disease in Childhood 78:571-574
F Bell, P Heath, F Shackley, J MacLennan, N Shearstone, L Diggle, H Griffiths, ER Moxon, A Finn. (1998) Effect of combination with an acellular pertussis, diphtheria, tetanus vaccine on antibody response to Hib vaccine (PRP-T). Vaccine 16:637-642
F Bell, P Heath, J MacLennan, F Shackley, N Shearstone, L Diggle, C Thornton, H Griffiths, ER Moxon, A Finn. (1999) Adverse effects and sero-responses to an acellular pertussis/diphtheria/tetanus vaccine when combined with Hib vaccine in an accelerated schedule. European Journal of Paediatrics 158:329-336
MacLennan, J., Obaro, S., Deeks, J., Williams, D., Pais, L., Carlone, G., Moxon, R. & Greenwood, B. (1999). Immune response to revaccination with meningococcal A and C polysaccharides in Gambian children following repeated immunisation during early childhood. Vaccine 17, 3088-3095.
F Bell, P Heath, F Shackley, J Maclennan, M Herbert, N Shearstone, L Diggle, Moxon ER, A Finn. (1999) Poor response to Hib (PRP-T) vaccine when combined with an acellular pertussis/diphtheria/tetanus vaccine for primary immunization of infants. Biologicals. Jun;27(2):113
MacLennan, J. M., Shackley, F., Heath, P. T. et al. (2000). Safety, immunogenicity, and induction of immunologic memory by a serogroup C meningococcal conjugate vaccine in infants: A randomized controlled trial. JAMA 283, 2795-2801.
MacLennan, J. M., Urwin, R., Obaro, S., Griffiths, D., Greenwood, B. & Maiden, M. C. (2000). Carriage of serogroup W-135, ET-37 meningococci in The Gambia: implications for immunisation policy? Lancet 356, 1078.
Nurkka, A., MacLennan, J., Jantti, V., Obaro, S., Greenwood, B. & Kayhty, H. (2000). Salivary antibody response to vaccination with meningococcal A/C polysaccharide vaccine in previously vaccinated and unvaccinated gambian children. Vaccine 19, 547-556.
English, M., MacLennan, J. M., Bowen-Morris, J. M. et al. (2001). A randomised, double-blind, controlled trial of the immunogenicity and tolerability of a meningococcal group C conjugate vaccine in young British infants. Vaccine 19, 1232-1238.
J MacLennan, S Obaro, J Deeks, D Lake, C Elie, G Carlone, ER Moxon, and B Greenwood. (2001) Immunologic memory 5 years after meningococcal A/C conjugate vaccination in infancy. Journal of Infectious Diseases 183:97-104.
MacLennan, J. (2001). Meningococcal group C conjugate vaccines. Arch Dis Child 84, 383-386.
D Elbourne, C Dezateux, R Arthur, NM Clarke, A Gray, A King, A Quinn, F Gardner, G Russell; UK Collaborative Hip Trial Group. (2002 ) Ultrasonography in the diagnosis and management of developmental hip dysplasia (UK Hip Trial): clinical and economic results of a multicentre randomised controlled trial. Lancet. Dec 21-28;360(9350):2009-17
James Stuart and Martin Maiden on behalf of The United Kingdom Meningococcal Carriage Group. (2002) Reduced carriage of serogroup C meningococci in teenagers one year after the introduction of meningococcal C conjugate polysaccharide vaccine in the United Kingdom. Lancet 2002;359:1829-1830
Joseph, H., Ryall, R., Bybel, M., Papa, T., MacLennan, J., Buttery, J. & Borrow, R. (2003). Immunogenicity and immunological priming of the serogroup a portion of a bivalent meningococcal A/C conjugate vaccine in 2-year-old children. J Infect Dis 187, 1142-1146.
J McVernon, J MacLennan, J Buttery, P Oster, L Danzig, ER Moxon. (2002) Safety and immunogenicity of meningococcus serogroup C conjugate vaccine administered as a primary or booster vaccination to healthy four-year old children. Pediatric Infectious Disease Journal 21(8):747-53.
McVernon, J., MacLennan, J., Pollard, A. J., Oster, P., Wakefield, M. J., Danzig, L. & Moxon, E. R. (2003). Immunologic memory with no detectable bactericidal antibody response to a first dose of meningococcal serogroup C conjugate vaccine at four years. Pediatric Infectious Disease Journal 22, 659-661.
J McVernon, J MacLennan, E Clutterbuck, J Buttery, ER Moxon. (2003) Effect of infant immunisation with meningococcus serogroup C-CRM(197) conjugate vaccine on diphtheria immunity and reactogenicity in pre-school aged children. Vaccine. Jun 2;21(19-20):2573-9.
C MacLennan , C Fieschi, DA Lammas, C Picard, SE Dorman, O Sanal, JM MacLennan, SM Holland, TH Ottenhoff, JL Casanova, DS Kumararatne. (2004) Interleukin (IL)-12 and IL-23 are key cytokines for immunity against Salmonella in humans. Journal of Infectious Diseases. 190(10):1755-7
F Gardner, C Dezateux, D Elbourne, A Gray, A King, A Quinn; Collaborative Hip Trial Group. (2005) The hip trial: psychosocial consequences for mothers of using ultrasound to manage infants with developmental hip dysplasia. Archives of Disease in Childhood Fetal Neonatal Ed. Jan;90(1):F17-24
C MacLennan and J MacLennan. (2005) What threat from persistent vaccine related poliovirus? Lancet 366(7): 351-353
MacLennan, J., Kafatos, G., Neal, K. et al. (2006). Social behavior and meningococcal carriage in British teenagers. Emerg Infect Dis 12, 950-957.
Maiden, M. C., Ibarz-Pavon, A. B., Urwin, R. et al. (2008). Impact of Meningococcal Serogroup C Conjugate Vaccines on Carriage and Herd Immunity. J Infect Dis 197, 737-743.
Snape, M. D., Maclennan, J. M., Lockhart, S., English, M., Yu, L. M., Moxon, R. E. & Pollard, A. J. (2009). Demonstration of immunologic memory using serogroup C meningococcal glycoconjugate vaccine. Pediatr Infect Dis J 28, 92-97.
Mandala WL, MacLennan JM, Gondwe EN, Ward SA, Molyneux ME, MacLennan CA. (2010) Lymphocyte subsets in healthy Malawians – implications for immunological assessment in HIV infection. Journal of Allergy and Clinical Immunology 125(1):203-8.
Ibarz-Pavon, A. B., Maclennan, J., Andrews, N. J. et al. (2011). Changes in serogroup and genotype prevalence among carried meningococci in the United Kingdom during vaccine implementation. J Infect Dis 204, 1046-1053.
Greenwood, B., Chiarot, E., MacLennan, C. A. & O’Ryan, M. (2012). Can we defeat meningococcal disease in low and middle income countries? Vaccine 30, Supplement 2, B63-B66.
Mandala WL, Ananworanich J, Apornpong T, Kerr SJ, MacLennan JM, Hanson C, Jaimulwong T, Gondwe EN, Rosenblatt HM, Bunupuradah T, Molyneux ME, Spector SA, Pancharoen C, Gelman RS, MacLennan CA, Shearer WT. (2014) Control lymphocyte subsets: can one country’s values serve for another’s? J Allergy Clin Immunol. 134(3):759-761
Maiden MC, MacLennan JM. (2014) Editorial commentary: fifteen years of protection by meningococcal C conjugate vaccines: lessons from disease surveillance. Clin Infect Dis. 2014 Nov 1;59(9):1222-4
Gilchrist JJ, Heath JN, Msefula CL, Gondwe EN, Naranbhai V, Mandala W, MacLennan JM, Molyneux EM, Graham SM, Drayson MT, Molyneux ME, MacLennan CA. (2016) Cytokine Profiles during Invasive Nontyphoidal Salmonella Disease Predict Outcome in African Children. Clin Vaccine Immunol. 5;23(7):601-9
Mandala WL, Gondwe EN, MacLennan JM, Molyneux ME, MacLennan CA. (2017) Age- and sex-related changes in hematological parameters in healthy Malawians. J Blood Med. 28;8:123-130.
Mandala WL, Gondwe EN, Molyneux ME, MacLennan JM, MacLennan CA. (2017) Leukocyte counts and lymphocyte subsets in relation to pregnancy and HIV infection in Malawian women. Am J Reprod Immunol. 78(3)