The Knowledge Hub

Introduction of PCV-10 in Kenya reduced pneumococcal bacteria in HIV-positive adults, highlighting benefits of immunization

Two years after the introduction of 10-strain pneumococcal conjugate vaccine (PCV-10) in Kenya, the percent of HIV-positive adults who carried pneumococcal bacteria declined significantly (from 43% to 28%), but did not decline in HIV-negative adults. However, the reduction in carriage of pneumococcal strains that are in PCV10 declined significantly in both HIV-positive and HIV-negative adults. This reduction was still four times higher in HI- positive vs. HIV-negative adults (2.8% vs. 0.7%), indicating that HIV positive adults continue to be at considerably higher risk of invasive pneumococcal disease than HIV-uninfected adults.

Nasopharyngeal carriage is an indicator of the risk for invasive pneumococcal disease and pneumonia

Kobayashi M, Bigogo G, Kim L et al.. 2020. Impact of 10-valent pneumococcal conjugate vaccine introduction on pneumococcal carriage and antibiotic susceptibility patterns among children aged <5 years and adults with HIV infection, Kenya 2009-2013. Clinical Infectious Diseases. 70(5).

Continuing vaccination in Kenya will prevent thousands of deaths and be cost-effective

An analysis in Kenya found that, although the government will need to more than double its current vaccine budget to continue using PCV after GAVI support ends, continuing the vaccination will prevent more than 101,000 cases of invasive pneumoccocal disease and pneumonia, more than 14,000 deaths over an 11-year period, and would be cost-effective (cost per DALY of $153 by 2032), even at the full GAVI price of US $3.05 per dose.

Ojal J, Griffiths U, Hammitt LL et al.. 2019. Sustaining pneumococcal vaccination after transitioning from Gavi support: a modelling and cost-effectiveness study in Kenya. Lancet Global Health. 7(5).

Wealth did not impact vaccination rates for Somali refugee children in Kenya, suggesting systemic barriers to immunization

In contrast to non-Somalis, family wealth did not significantly affect the likelihood of being fully vaccinated among Somali refugee children living in Kenya. This may point to systemic barriers to vaccination that cut across all socio-economic levels of the Somali refugee population.

Masters NB, Wagner AL, Carlson BF et al.. 2019. Childhood vaccination in Kenya: Socioeconomic determinants and disparities among the Somali ethnic community. International Journal of Public Health. 64(3).

Children born outside of a health facility in Kenya are less likely to be vaccinated

Kenyan children born outside of a health facility with the aid of a traditional birth attendant were around 80% more likely to be non-vaccinated or under-vaccinated than children born in a government health facility.

Masters NB, Wagner AL, Carlson BF et al.. 2019. Childhood vaccination in Kenya: Socioeconomic determinants and disparities among the Somali ethnic community. International Journal of Public Health. 64(3).

Children from poor households in Kenya are less likely to be vaccinated compared to wealthier children

Non-Somali children in Kenya in the poorest households were nearly three times as likely to be unvaccinated than children from middle-income households, while wealthier children were significantly less likely to be unvaccinated.

Masters NB, Wagner AL, Carlson BF et al.. 2019. Childhood vaccination in Kenya: Socioeconomic determinants and disparities among the Somali ethnic community. International Journal of Public Health. 64(3).

Refugee children in Kenya have significantly lower immunization rates

Somali refugee children in Kenya were nearly 60 times more likely than children of the main ethnic group in the study (Kikuyu) to not have received any childhood immunization and more than twice as likely to have not completed their vaccinations. Although Somali children made up less than 8% of the sample, they accounted for nearly half of all non-vaccinated children.

This study used data from Kenya’s Demographic and Health Survey data.

Masters NB, Wagner AL, Carlson BF et al.. 2019. Childhood vaccination in Kenya: Socioeconomic determinants and disparities among the Somali ethnic community. International Journal of Public Health. 64(3).

Educating women can help increase infant immunization rates in Kenya

Data from the Kenya Demographic and Health Survey show that women with a primary school education were 2 to 5 times more likely to have their infants vaccinated (depending on the vaccine) and women with a secondary school education were 2.5 to 9 times more likely to have their infants vaccinated than mothers with less than a primary education or no education [after adjusting for wealth, age, religion and other variables].

Onsomu EO, Abuya BA, Okech IN et al.. 2015. Maternal education and immunization status among children in Kenya. Maternal and Child Health Journal. 19(8).

Immunization with PCV reduced the risk of pneumococcal pneumonia in HIV-positive adults in Kenya

Prior to the introduction of PCV, adults with HIV in a rural area of Kenya were nearly five times more likely to have pneumococcal pneumonia than non-infected adults, and the majority of cases with bacteremia (blood infection) occurred in HIV positive individuals.

Bigogo GM, Audi A, Auko J et al.. 2019. Indirect effects of 10-Valent pneumococcal conjugate vaccine against adult pneumococcal pneumonia in rural western Kenya. Clinical Infectious Diseases. 69(12).

PCV-10 vaccine reduced rates of pneumococcal pneumonia in adults in Kenya, including those with HIV

The introduction of PCV-10, along with a “catch-up” campaign for 1-4 year olds, led to dramatic reductions in the rates of pneumococcal pneumonia in adults (≥18 years old) in a rural area of Kenya with high rates of both adult pneumococcal pneumonia and HIV. Over five years following the vaccine introduction, the incidence rates among adults were 47-94% lower each year than in the pre-vaccine period, with similar declines for HIV-infected and HIV-uninfected adults.

Bigogo GM, Audi A, Auko J et al.. 2019. Indirect effects of 10-Valent pneumococcal conjugate vaccine against adult pneumococcal pneumonia in rural western Kenya. Clinical Infectious Diseases. 69(12).

Even in hard-to-reach areas measles vaccination is cost-effective and beneficial for public health

An outreach strategy in Kenya to vaccinate children against measles in hard-to-reach areas (e.g., beyond 5 km from a vaccination post) would be highly cost-effective, despite the higher cost per child to reach these children. The estimated cost per DALY averted ranged from US$122 (if 50% of these children receive the first dose and one-half of them the second dose) to US$274 (if 100% receive the first dose) — considerably less than the country’s GDP per capita of US$1,865 used as the threshold of cost-effectiveness.

Lee BY, Brown ST, Haidari LA et al.. 2019. Economic value of vaccinating geographically hard-to-reach populations with measles vaccine: A modeling application in Kenya. Vaccine. 37(17).