Sumit Perakathu, MD and Arber Nuhaj, MD
The Community-Acquired Pneumonia Immunization Trial in Adults (CAPITA) is a randomized, double-blind, placebo controlled trial conducted in the Netherlands. This purpose of the trial was to evaluate the efficacy of the PCV13 vaccine in preventing a first episode of pneumococcal pneumonia, primarily in healthy adults. During my training I came across variable practices and opinions on the use of PCV13 vaccine. There is also medical literature and clinics that openly state they do not use the PCV13 vaccine in healthy adults over age 65, despite the Advisory Committee on Immunization Practices’ (ACIP) recommendations. A Sep 19, 2014 issue from the CDC Morbidity and Mortality Weekly (MMW) report stated the Prevnar was approved under the FDA’s accelerated approval pathway. Considering the confusion and the different practices we decided to look at the CAPiTA trial, which is the trial that is often referred to as the basis for ACIP’s and FDA’s recommendations.
The study was conducted in the Netherlands and included 84,496 adults, 65 years of age or older. The study population was roughly divided in the equal halves of a placebo group and a vaccinated group. However strict exclusion criteria were used and out of the 42,240 individuals in the PCV13 vaccinated group, 155 cases of first episode pneumococcal pneumonia were identified, compared to the placebo group, where out of 42,256 subjects there were 202 cases of first episode pneumococcal pneumonia. There was a decrease in roughly 50 cases noted between the two groups. Their trial also noted there was no difference in serious adverse events and deaths between both groups.
Our take on the CAPiTA trial, was that it was a good research trial for evaluating the efficacy of PCV13, however there are aspects of this trial that prevent it from being an ideal study to be used as evidence of pneumonia prevention in the United States. Out of 84,496 individuals, only 357 were reported to have had a first episode of pneumococcal pneumonia.
- The authors of the trial noted that the urine assay that was used to screen for the causative strains of pneumococcus was highly sensitive and may have overestimated the number of cases, making the true cases of pneumococcal pneumonia less than 357 out of 84,496, with an unknown effect on true efficacy.
- The study had a very homogenous population where 98.5% of the subjects were Caucasian, 0.3% Black, 0.7% Asian and 0.5% other which is significantly different from the population in the United States making it difficult to generalize the outcomes for a very mixed population such as ours considering the different genetic, social and economic characteristics.
- According to the statistics of the trial, it would cost millions, if not billions of dollars to vaccinate every healthy individual over the age of 65 in the United states, only to show a sub-par to moderate reduction of first case pneumococcal pneumonia.
- There was not difference in number of complications or deaths between the vaccinated group and the placebo group if the subjects developed pneumonia.
- The trial does not provide enough evidence to justify the cost and efficacy of PCV-13 use here in the US, however there will be a review of its use and recommendations are expected to come in 2018. Hopefully at that time we will have a trial more applicable to the general population here in the United States.
N Engl J Med 2015; 372:1114-1125March 19, 2015DOI: 10.1056/NEJMoa1408544