Respiratory infections during pregnancy may exert indirect effects on the developing fetus through placental function and maternal immune responses. This in turn may lead to pre-term births and reduced growth of the fetus. However, a review of recent studies, researchers show that administration of influenza vaccine during pregnancy adds 200 grams to newborn weight and that PCV7 vaccine given to infants translates into an additional 500 grams of growth in the first 6 months of life. In addition, maternal influenza vaccine led to a 15% reduction in low birth-weight. This indicates that immunization can improve intrauterine growth.
Pneumococcal disease/PCV/PPSV
Antibiotic resistance in pneumococcal infections is common among Indian children
A systematic review of studies from India found that prior to widespread use of the pneumococcal conjugate vaccine, antibiotic resistance in serious pneumoccocal infections among Indian children has been common. Penicillin resistance was found in 10% of invasive pneumococcal disease (IPD) cases, while trimethoprim/sulfamethoxazole resistance was found in more than 80% of these cases.
Immunocompromised people are particularly vulnerable to IPD
In a long-term study of Canadian surveillance data researchers found that immunocompromised people were at a 12-fold risk of invasive pneumococcal disease (IPD) compared to healthy people. In addition, the risk of death from IPD in immunocompromised people was found to be 30-80% higher than healthy individuals who had contracted IPD. 10 years after introduction of PCV7 in Canada, the incidence of IPD due to serotypes included in the vaccine had decreased by 90%.
Undernourished children have a higher likelihood for diarrhea and pneumonia but immunization can improve infant growth
Multiple studies show that
- Diarrhea and pneumonia impair children’s growth and that underlying malnutrition is a major risk factor for these conditions.
- “Episodes of diarrhea may predispose to pneumonia in undernourished children” and
- Immunization against influenza (in mothers) and Streptococcus pneumoniae may improve infant growth. In addition, new studies from Bangladesh, Colombia, Ghana, and Israel further support the paradigm that malnutrition is a key risk factor for diarrhea and pneumonia.
Diarrhea is associated with pneumonia in undernourished children
In a recent review of data from developing countries, researchers found that episodes of diarrhea may predispose undernourished children to pneumonia.
Pneumococcal disease vaccines significantly reduced cases within the first years of use
Data obtained through active surveillance pre and post introduction of PCV in the US showed that the vaccine averted an estimated 38,000 cases of invasive pneumococcal disease within its first five years of use. Additionally, 71,000 cases of disease were estimated to be prevented by herd effects.
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.
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.
Children with sickle cell disease stand to benefit enormously from PCV and Hib immunization
Nearly a quarter of a million children are born with sickle cell disease in Africa each year. Sickle cell disease was found to increase the risk of Hib infections by 13-fold and pneumococcal infections by 36 fold. This means that children with sickle cell disease stand to benefit enormously from PCV and Hib immunization.
People who are HIV-positive are particularly vulnerable to invasive pneumococcal disease
In a study of national surveillance records in South Africa, HIV positive people over 5 years of age were found to have a 43-fold risk of invasive pneumococcal disease compared to HIV negative person. This risk was highest among children age 5-19 who were found have a more than 120-fold risk of invasive pneumococcal disease compared to HIV negative uninfected children of the same age. 90% of South Africa’s invasive pneumococcal disease cases during the 5 year period occurred in the 18% of the population who are HIV positive.