PREDICTED IMPACT OF THE HIV-1 EPIDEMIC ON MEASLES IN DEVELOPING COUNTRIES: RESULTS FROM A DYNAMIC AGE-STRUCTURED MODEL

Tuesday, 20th of August 2013

[source]International Journal of Epidemiology[|source]

High overall mortality in HIV-1-infected children without access to ART limits the impact of HIV-1 on MV transmission and may help to explain the initial success of current measles control strategies Africa. The scaling-up of ART should improve childrens survival, BUT, immune reconstitution following ART is likely to be with naïve rather than memory T-cells. If children vaccinated before ART still have higher vaccine failure rates than HIV-1-uninfected children, in settings where only one dose of measles vaccine is provided, increasing provision of ART to HIV-1-infected children could lead to an increase in measles cases. This puts more urgency in implementation of WHO recommendation for countries to provide two opportunities for measles vaccine, through a routine second dose or periodic supplementary campaigns. But most importantly, more information is needed on the duration of immunity in HIV-1-infected children receiving ART and their response to revaccination to determine whether a second dose of measles vaccine will protect these children and reduce MV transmission in regions of high HIV-1 prevalence. More details available at:  http://ije.oxfordjournals.org/content/37/2/356.long 

 

Abstract

BACKGROUND: Although measles incidence has been reduced to low levels in many countries, the potential exists for HIV-1 infection to enhancemeasles virus (MV) transmission and hinder measles control and elimination efforts.

METHODS: HIV-1 infection was incorporated into an age-structured, deterministic compartmental model of MV transmission. Parameter estimates were obtained from published studies. The model was then adapted to simulate the introduction of antiretroviral therapy (ART).

RESULTS: The model suggests that prior to the introduction of ART, HIV-1 infection has little impact on the transmission dynamics of MV. High mortality rates in HIV-1-infected children without access to ART counteract the higher rates of vaccine failure, shorter duration of maternal antibody protection and longer duration of infectiousness in HIV-1-infected children, as many of these children die before they are able to contribute to MV transmission. The introduction of ART into the model resulted in an increase in measles prevalence.

CONCLUSIONS: High overall mortality among HIV-1-infected children without access to ART limits the impact of the HIV-1 epidemic on MV transmission and may help to explain the initial success of measles control strategies in Africa. The scaling-up of ART should improve childrens survival but could lead to an increase in measles prevalence in the absence of sustained measles control efforts. Further study of the duration of immunity in HIV-1-infected children receiving ART and their response to revaccination is needed to determine whether a second dose of measles vaccine will protect these children and further reduce MV transmission.