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This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
Pneumococcal vaccines reduce the risk of community-acquired pneumonia in people with moderate to severe chronic obstructive pulmonary disease (COPD).
Pneumococcal vaccination is currently recommended for people with COPD and other respiratory diseases. However, until now there has been a lack of data whether it actually improves outcomes in these groups.
This updated Cochrane review identified 12 trials including 2171 adults with COPD, comparing those who did and did not receive pneumococcal vaccination. One episode of community-acquired pneumonia was prevented for every 21 people vaccinated. There was also evidence that vaccination reduced the risk of exacerbations of COPD. However, vaccination had no effect on deaths from respiratory causes or likelihood of hospitalisation.
This evidence lends further support to current government recommendations to provide the pneumococcal vaccine to people with COPD.
Why was this study needed?
COPD involves irreversible, usually progressive, shortness of breath and frequent chest infections. It affects around three million people in the UK, predominantly adults aged over 40 years who have smoked. In 2005, the Department of Health estimated an annual direct NHS healthcare cost of COPD of over £800 million. COPD led to over 113,000 emergency hospital admissions in 2013-2014.
People with COPD are at greater risk of pneumonia and its complications than healthy adults, and Streptococcus pneumoniae bacteria is a common cause, though not always identified as a cause of exacerbations of COPD. In the UK, a vaccine is recommended to protect at-risk adults, including those with COPD. However, much evidence for the effect of the vaccine comes from observational studies or trials in people without COPD.
This updated Cochrane review aimed to gather the available evidence to see whether vaccination prevents community-acquired pneumonia and improves other outcomes for people with COPD.
What did this study do?
The review identified 12 randomised controlled trials (five additional since the last review) including 2171 adults with moderate or severe COPD. Eligible trials compared people receiving a pneumococcal vaccine with a group receiving a placebo, no treatment or alternative vaccine. Trial participants were an average 66 years old. Vaccines were almost all of the polysaccharide type.
There was potential for bias around the lack of blinding of participants and personnel. There was little variability in the results of the individual trials making it appropriate to pool their findings. The overall quality of evidence for reducing pneumonia across six trials was assessed as moderate.
What did it find?
- Pneumococcal vaccines reduced the risk of community-acquired pneumonia, though very few of these in the control group were identified as pneumococcal pneumonia. Nine percent of vaccinated participants developed pneumonia in the 36 months after vaccination, compared with 14% of the control group (odds ratio [OR] 0.62, 95% confidence interval [CI] 0.43 to 0.89; six trials, 1372 adults).
- The researchers calculated that 21 people would need to be vaccinated to avoid one episode of community-acquired pneumonia (95% CI 15 to 74 people).
- Vaccination also reduced risk of acute exacerbations of COPD, which occurred in 48% of participants up to 24 months after vaccination, compared with 61% of the control group (OR 0.60, 95% CI 0.39 to 0.93; four trials, 446 adults). An estimated eight people would need to be vaccinated to prevent one acute exacerbation (95% CI 5 to 58).
- There was no difference between groups in mortality rate or deaths from respiratory disease (up to 48 months after vaccination) or likelihood of hospital admission (up to 12 months after vaccination).
What does current guidance say on this issue?
Public Health for England’s Green Book (2013) recommends the polysaccharide PPV-23 vaccine for all adults aged 65 and over, and other children or adults with risk factors, which includes COPD and other respiratory diseases. Current NICE guidelines on management of COPD (due for update in 2018) also recommend pneumococcal vaccination.
The Joint Committee on Vaccination and Immunisation stated in 2015 that there was no evidence that the PPV-23 vaccine reduced risk of community-acquired pneumonia or mortality in over-65s and at-risk groups.
What are the implications?
For the first time, we have systematic review evidence specific to COPD to support government recommendations to provide pneumococcal vaccination for this group.
There isn’t yet sufficient evidence to decide which is the best type of vaccine (conjugate or polysaccharide) or to conclude if there are differences in their cost effectiveness.
Health Protection Agency statistics (2009) showed only half of people aged 16-64 years with chronic respiratory disease receive pneumococcal vaccination. This was lower than the 75% uptake for all adults aged 65+ years. So it would be helpful to explore any barriers to vaccine uptake among people with COPD.
Citation and Funding
Walters JA, Tang JN, Poole P, Wood-Baker R. Pneumococcal vaccines for preventing pneumonia in chronic obstructive pulmonary disease. Cochrane Database
Syst Rev. 2017;1:CD001390.
This project was supported by the National Institute for Health Research (NIHR), via Cochrane Infrastructure funding to the Cochrane Airways Review Group.
Bibliography
NHS Choices. COPD. London: Department of Health; 2016.
NHS Choices. Pneumococcal vaccine. London: Department of Health; 2016.
NICE. Chronic obstructive pulmonary disease in over 16s: diagnosis and management. CG101. London: National Institute for Health and Care Excellence; 2010.
NICE. Chronic obstructive pulmonary disease: Costing report: Implementing NICE guidance. CG101. London: National Institute for Health and Care Excellence; 2011.
PHE. Pneumococcal: the green book, chapter 25. London: Public Heath England; 2013.
JCVI. JCVI interim statement on adult pneumococcal vaccination in the UK. London: Joint Committee on Vaccination and Immunisation; 2015.
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