Children who receive a vaccine to prevent blood and ear infections are reducing the spread of pneumonia to the rest of the population, especially to their grandparents and other older adults.
The results published in the New England Journal of Medicine found that vaccinating infants against pneumococcal bacteria since 2000 has reduced overall hospitalisation due to pneumonia by more than 10 per cent. In children under age 2 this reduction in hospitalisation was as great as 40 per cent.
The researchers looked at a large database for hospitalisation from pneumonia from 1997 to 2009 in the USA. This showed a long-term pattern of how the vaccine pneumococcal conjugate (PCV7 or Prevnar) has affected pneumonia rates since 2000, when children first started being vaccinated.
PCV7 was developed to protect children against seven types of pneumococcal bacteria that cause serious blood and spinal infections, sometimes death. The bacteria are also well known as a leading cause of lung and ear infections in young children.
Dr Marie Griffin, lead author of the study, says, “The protective effect we saw in older adults, who do not receive the vaccine but benefit from vaccination of infants, is quite remarkable. It is one of the most dramatic examples of indirect protection or herd immunity we have seen in recent years.”