We read with interest the paper by Klippel et a1 (1) purporting that patients with systemic lupus erythematosus (SLE) might benefit by prophylactic use of polyvalent pneumococcal vaccine.
The data presented do not seem to point toward convincing conclusions. In the patients vaccinated, a base titer of antibodies against 12 antigens was present. The response to a recurrent antigenic stimulation does not differ basically from that observed in normal humans (2). The question of vaccination in SLE patients with a known decrease of immunologic defense mechanisms is of importance, particularly in patients without any previous contact with infective agents in whom an undetectable titer of antibodies exists.
Regarding immunologic response, we would like to add that although no change was observed in titers of anti-gammaglobulin, DNA binding capacity, and complement levels, this still does not exclude a partial and transient serologic activation of the disease in earlier stages. As pointed out by the authors, use of the vaccine seems to be safe during a short term followup, but some other questions may be asked: 1) How long are these titers maintained? 2) How would the acutely ill patients (who are perhaps more susceptible to infection) not included in the study react?
We choose, therefore, not to speculate on possible "benefits" since this is very difficult, if ever, to prove, as is the case with influenza vaccine in these patients (3).