A notable week for new vaccine recommendations for immunocompromised individuals, but could be confusing for some. Also, a bit of new information about a medical mystery that's been brewing the past few months.
3rd Dose of COVID-19 Vaccine for Moderately to Severely Immunocompromised People
Both FDA and ACIP weighed in this week to recommend a 3rd dose of mRNA vaccine to a subset of immunocompromised people. (Not enough data at this time to make any judgment for those who received Janssen/Johnson&Johnson vaccine.) These individuals as a group tended not to respond with robust immunity after the standard 2-dose regimen, and now we have some new data suggesting a modest improvement after a 3rd dose. Note however that this is just a modest improvement, many individuals still may not be protected after the 3rd dose and all should continue to use masks, social distancing, and good judgment in avoiding crowds, etc., as if they were not immunized. It is tough to exactly spell out what moderate/severe immunocompromise is, but essentially all of these patients are being followed closely by whomever is prescribing their treatments and would be able to advise them on an individual basis. CDC provides excellent explanations.
Ever Seen a Case of Melioidosis?
I haven't, and I hope I don't. It's a serious infection caused by Burkholderia pseudomallei that normally is seen mostly in adults with underlying conditions residing in eastern Asia, northern Australia, and to a lesser extent in Africa, the Caribbean basin, and Central and South America. This past week the CDC reported the 4th case of melioidosis in the US this year not connected with any travel or other risk factors for the disease or to each other. These isolated cases have occurred in Texas, Kansas, Minnesota, and Georgia. Two of the 4 cases have occurred in children. Furthermore, genetic testing has shown all 4 isolates to be closely related so likely from a common source, as yet unidentified.
The clinical presentation often is nonspecific, with severe pneumonia and/or a typical septic shock presentation. Sometimes draining abscesses can develop. The organism is high risk to lab personnel and they should be warned if meliodosis is suspected. Also, many of the automated and high-tech laboratory identification machines can misidentify this organism; I suspect all the clinical labs in our area are aware of this since so many notifications have gone out, but if by chance you have a severely ill patient with a bacterial culture growing any Burkholderia species (especially B. cepacia or B. thailandensis) or Chromobacterium violaceum, Ochrobactrum anthropi, Acinetobacter spp., Aeromonas spp., and maybe even Pseudomonas spp., please check with the lab.