Fewer children hospitalised with pneumonia complications after vaccine switch

The number of children admitted to English hospitals with serious complications of bacterial pneumonia fell after a new vaccine was introduced.

Admissions for empyema, a rare but serious complication of bacterial pneumonia that hinders breathing, fell by 42 per cent in children under two in the two years after the change in 2010, according to research by Imperial College London.

Bacterial pneumonia is caused by Streptococcus pneumoniae bacteria, which mostly affect babies, young children and elderly people. Bacterial pneumonia usually develops as a complication following a respiratory tract infection such as influenza. Symptoms include difficulty breathing, wheezing and fever. In Europe, around one in ten deaths in the under-fives is caused by the disease.

Pneumococcal vaccination was first introduced into the childhood immunisation programme in 2006. Infections fell in the next two years, but began to climb soon afterwards, largely due to a number of strains that were not covered by the vaccine.

In 2010, the PCV7 vaccine was replaced by a PCV13, which protects against a wider range of strains.

The Imperial researchers studied Hospital Episode Statistics from 2001 to 2014 to determine the effect of the vaccination programme.

The findings, published in the Journal of Infection, show that prior to the introduction of PCV7, there were 15,733 hospital admissions for bacterial pneumonia and 382 for empyema among children under 15 in 2005. By 2013 this had fallen to 11,411 pneumonia and 205 empyema cases respectively.

After the switch to PCV13, there was a fall in admissions for empyema, a life-threatening complication in which pus collects in the space inside the lung lining. However, overall admissions for pneumonia did not fall lower than levels seen after the PCV7 vaccine was introduced. The reason for this is unclear, but might be because new strains have emerged, or because more time is needed to see an effect.

Study author Dr Sonia Saxena from the School of Public Health at Imperial College London, who is also a South London GP, said: “The success of any vaccination programme depends on vaccinating as many people as possible. We are fortunate that in England every child has access to primary care, and that is the main reason why in the first few years of the programme, we have been able to get over 90 per of infants vaccinated by their first birthday.

“However, even with this programme in place, bacterial pneumonia remains an important cause of illness among children. The threat of serious bacterial infection continues as new strains of bacteria adapt. This study illustrates the importance of having responsive surveillance programmes such the UK Health Protection Agency that can monitor which strains are causing problems, as well as good systems in place to monitor disease when it occurs.

“The benefits of vaccination are immense. In addition to having fewer children succumb to this serious infection, reducing the disease in the population means that fewer vulnerable adults such as pregnant women, those with poor immunity and elderly people are affected. In theory there should also be a reduction in the need to prescribe antibiotics that will in turn limit the risk of resistance.”

The study was funded by the National Institute for Health Research.

See the press release of this article