The Knowledge Hub

Immunizing pregnant women protects infants from influenza, with 56% efficacy in the first 2 months of life

A pooled analysis of three randomized controlled trials conducted in Nepal, Mali, and South Africa between 2011 and 2014 found that immunization during pregnancy provided protection against influenza to young infants from birth through 4 months of age. Protection against infant influenza was greatest in the first 2 months of life, with 56% efficacy, and the pooled efficacy of maternal vaccination to prevent infant laboratory-confirmed influenza up to 6 months of age was 35%.

Omer SB, Clark DR, Madhi SA et al.. 2020. Efficacy, duration of protection, birth outcomes, and infant growth associated with influenza vaccination in pregnancy: a pooled analysis of three randomised controlled trials. The Lancet Respiratory Medicine. 8(6).

Immunization rates are low among pregnant adolescents in rural areas with less education and lower wealth

The use of antenatal care (ANC) services among pregnant adolescents in low- and middle-income countries, including tetanus toxoid vaccination, was lowest among women who lived in rural areas, had completed less education, and who were of poorer wealth quintiles.

Banke-Thomas OE, Banke-Thomas AO, Ameh CA. 2017. Factors influencing ultilisation of maternal health services by adolescent mothers in Low- and middle-income countries: a systematic review. BMC Pregnancy Childbirth. 17(1).

Influenza vaccination during pregnancy reduces severe pneumonia rates in infants, especially during peak influenza circulation

An analysis of data from three studies showed that the rates of severe pneumonia in infants in their first six months of life was 20% lower overall in infants whose mothers received the influenza vaccination during pregnancy than in infants whose mothers had not, and the rates of severe pneumonia was 56% lower during periods when influenza circulation was highest. These findings correspond with evidence that influenza infection predisposes individuals to pneumococcal infection.

The incidence rate of severe pneumonia in the vaccine group compared to the control group was 43% lower in South Africa, 31% lower in Nepal, but not significantly different in Mali.

Omer SB, Clark DR, Aqil AR et al.. 2018. Maternal influenza immunization and prevention of severe clinical pneumonia in young infants: Analysis of randomized controlled trials conducted in Nepal, Mali and South Africa. Pediatric Infectious Disease Journal. 37(5).

Universal hepatitis B vaccination for newborns in refugee camps is highly cost-effective

Providing a birth dose of hepatitis B vaccine to all newborns (in addition to routine HepB immunization) was found to be a highly cost-effective means of preventing hepatitis B-related deaths in three refugee populations in Africa which are at extremely high risk of hepatitis B infection. Providing a birth dose only to newborns whose mothers test positive on a rapid diagnostic test was less cost-effective than vaccinating all newborns automatically. Thus, universal hepatitis B vaccination of newborns should remain a priority in refugee camps, despite competing humanitarian needs.

Reardon JM, O'Connor SM, Njau JD et al.. 2019. Cost-effectiveness of birth-dose hepatitis B vaccination among refugee populations in the African region: a series of case studies. Conflict and Health. 13(5).

Adding hepatitis B vaccine to routine immunization for refugees in Africa reduces transmission and improves global health security

Adding a birth dose of hepatitis B vaccine to routine immunization of refugees in Africa — who have particularly high infection rates — is a highly cost-effective means of reducing transmission of the infection thus strengthening the overall global health security among these mobile, vulnerable populations.

Reardon JM, O'Connor SM, Njau JD et al.. 2019. Cost-effectiveness of birth-dose hepatitis B vaccination among refugee populations in the African region: a series of case studies. Conflict and Health. 13(5).

Vaccinating all healthcare workers against Ebola could have dramatically reduced cases

Using data on the spread of Ebola from person to person during historical Ebola outbreaks to compare vaccination strategies, researchers found that prophylatically vaccinating all healthcare workers would have decreased the number of disease cases in the 2014 epidemics in Guinea and Nigeria by 60-80%.

Coltart CE, Johnson AM, Whitty CJ. 2015. Role of healthcare workers in early epidemic spread of Ebola: policy implications of prophylactic compared to reactive vaccination policy in outbreak prevention and control. BMC Medicine. 13(271).

The empowerment of women is associated with higher odds of childhood vaccinations

A systematic review of studies from countries in Africa and Southeast Asia investigated the relationship between a woman’s “agency” (defined as the woman’s ability to state her goals and to act upon them with motivation and purpose) and childhood immunizations in lower-income settings. The review found a general pattern among studies in which higher agency among mothers was associated with higher odds of childhood immunizations. Empowering women in these settings shows promise as a means to improve child health.

Thorpe, S., VanderEnde, K., Peters, C., et al.. 2016. The influence of women’s empowerment on child immunisation coverage in low, lower-middle, and upper-middle income countries: a systematic review of the literature.. Maternal and Child Health Journal. 20(1).

Vaccines are most cost-effective in low income countries

An analysis of the impact of rotavirus vaccine in 25 countries found that the rates of vaccination in all countries were highest and risk mortality lowest in the top two wealth quintile’s coverage. Countries differed in the relative inequities in these two underlying variables. Cost per DALYs averted in substantially greater in the higher quintiles. In all countries, the greatest potential vaccine benefit was in the poorest quintiles; however, reduced vaccination coverage lowered the projected vaccine benefit.

Rheingans, R., Atherly, D., and Anderson, J.. 2012. Distributional impact of rotavirus vaccination in 25 GAVI countries: Estimating disparities in benefits and cost-effectiveness. Vaccine. 30(1).

Pediatric pneumococcal or Hib meningitis surviviors had a higher likelihood for neuropsychological deficits

In a systematic literature review of studies in Africa, it was found that 25% of children who survived pneumococcal or Hib meningitis had neuropsychological deficits.

Ramakrishnan, M., Ulland, A.J., Steinhardt, L.C., et al. 2009. Sequelae due to bacterial meningitis among African children: a systematic literature review. BMC Medicine. 7(47).

Bacterial meningitis is associated with long-term neurophysiological impacts

A systematic literature review analyzing data from 21 African countries revealed that bacterial meningitis is associated with high case fatality and frequent neurophysiological sequelae. Pneumococcal and Hib meningitis contribute to one third of disease related mortality. They also cause clinically evident sequalae in 25% of survivors prior to hospital discharge. The three main causes of bacterial meningitis- Haemophilus influenzae type B; Streptococcus pneumoniae (pneumococcus) and Neisseria meningitidis (meningococcus) are vaccine preventable, routine use of conjugate vaccines have potential for significant health and economic benefits.

Neuropsychological sequelae includes hearing loss, vision loss, cognitive delay, speech/language disorder, behavioural problems, motor delays/impairment, and seizures.

Ramakrishnan, M., Ulland, A.J., Steinhardt, L.C., et al. 2009. Sequelae due to bacterial meningitis among African children: a systematic literature review. BMC Medicine. 7(47).