Protocol No: ECCT/18/04/02 Date of Protocol: 03-11-2017

Study Title:

Impact of HIV Infection and Malaria Parasitemia on Immunogenicity of Inactivated Influenza Vaccine in Pregnant Women and on Mother-to-Child Vaccine-induced Antibody Transfer

Study Objectives:
Primary Objectives
  1. To evaluate the immunogenicity of IIV in HIV-infected pregnant women and women with peripheral malaria parasitemia at the time of vaccination.
  2. To evaluate the level of vaccine-induced influenza antibody transfer to infants of HIV-infected and uninfected pregnant women who receive IIV early in pregnancy.
  3. To evaluate the level of vaccine-induced influenza antibody transfer to infants of mothers who had peripheral malaria parasitemia by Rapid Diagnostic Test for malaria at the time of influenza vaccination during pregnancy.
Secondary Objectives
  1. To evaluate the impact of HIV infection and peripheral malaria parasitemia on the duration of influenza vaccine-induced antibodies transferred to infant.
Laymans Summary:

Studies have shown that influenza can be severe among pregnant women and newborn babies. Influenza vaccination during pregnancy can protect pregnant women. Also, women vaccinated against influenza during pregnancy can pass on protective antibodies to their babies who are too young (<6 months of age) to be directly vaccinated. Influenza vaccination has been offered to pregnant women around the world for many years and data show the vaccine to be safe, for the mother and their unborn babies. Based on evidence from such studies, the advisory group of experts on immunization from the WHO recommended influenza vaccination to pregnant women. Sub-Saharan Africa has a high percentage of the population suffering from HIV and malaria; these diseases may affect how pregnant women respond to influenza vaccine and therefore affect the amount of protection transfered to their newborn babies. We propose to carry out a demonstration project using an influenza vaccine licensed in Kenya to vaccinate pregnant women in a setting of western Kenya with high rates of HIV among the population and malaria presence throughout the year. Results from this study will inform the Ministry of Health on policy and startegies for vaccinating mothers to protect these two high-risk groups. These results will also be applicable to other countries with similar HIV and malaria burden and may inform their policies on vaccination of pregnant women.

Abstract of Study:
In 2012, the WHO Strategic Advisory Group of Experts (SAGE) on immunizations made a recommendation for influenza vaccination of pregnant women. This was based upon compelling evidence of substantial risk of severe disease in this group and the safety and effectiveness of seasonal influenza vaccine in preventing disease in pregnant women as well as their young infants, in whom disease burden is also high. Sub-Saharan Africa has a high prevalence of HIV and malaria, the presence of which among expectant mothers can reduce response to influenza vaccination, and therefore affect transfer of vaccine-induced antibodies to their newborn babies. There is no documention on the effect of malaria parasitemia on influenza vaccination in pregnant women and their newborns. Few studies have shown reduced immunogenicity of influenza vaccine and associated antibody transfer among pregnant women with HIV, however the studies were done late in the course of pregnancy. We propose to conduct an influenza vaccine demonstration project, using an Inactivated Influenza Vaccine (IIV) already licensed in Kenya to vaccinate pregnant women in a high HIV prevalence and malaria-endemic setting in western Kenya. Documentation of vaccine-induced antibody transfer from vaccinated mothers to their babies is essential and key to informing the Kenya Ministry of Health on maternal immunization policy and strategy for these high-risk groups. Western Kenya is a resource-limited setting with high burden of influenza disease among infants. Vaccinating pregnant women for better outcomes in both mother and infant would therefore be a cost effective strategy in preventing influenza disease in two high-risk groups. Data from this study will also help inform influenza vaccine deployment in other countries with similar HIV and malaria profiles. If adopted by the government, maternal influenza immunization could be an important public health strategy in resource constrained settings to protect infants <6 months, not eligible for influenza vaccination themselves, and their mothers from influenza disease and associated complications.