Who needs to get these vaccines? Obviously if your patient’s spleen was surgically removed, they should get it. But what about patients who underwent angioembolization? Unfortunately, the only data available is either very old or is based on antibody response to the vaccine. And antibody titers do not predict immunity to infection, so these studies are close to meaningless.
Old research showed that the spleen’s immune function was preserved as long as 50% of its blood flow was delivered through the splenic artery. How can you tell if half of the spleen is still functioning after splenic angioembolization? Look at the images and make an educated guess. If in doubt, vaccinate.
When is the best time to vaccinate? There has been much gnashing of teeth regarding early vs late vaccination. The arguments against early vaccination center around the typical immune suppression seen with major trauma. However, trauma patients frequently do not appear for all their followup visits and would not receive vaccines at all if they are a no-show. So I recommend vaccinating as early as possible during the hospital stay to avoid forgetting. The data recommending waiting until just before discharge are also based on antibody titers, and I don’t buy it.
Bottom line: I’m not an epidemiologist. But making a set of vaccination rules more complicated for a complex population seems unwise. Especially since the added vaccine offers protection for only one more serotype of Pneumococcus.
But I can’t argue with the FDA and CDC. I have no idea of the wheeling and dealing that occurred to get the new vaccine approved. All we can do is follow the recommendations the best we can, and try to remind our patients to get that Pneumovax and meningococcal conjugate booster five years down the road. Good luck with that.