Prevention of infectious complications in the transplanted patient is a cornerstone of care in this vulnerable population. After transplantation, detailed preemptive and prophylactic protocols are in place and have markedly reduced some infectious diseases, primarily with traditional opportunistic pathogens such as cytomegalovirus and Toxoplasma gondii.1 However, a great opportunity to optimally prepare all candidates for immunosuppression is often missed: assessing and updating the vaccination status before transplantation. Three exemplary studies make a case in point. Waller et al2 reported on notifiable infectious diseases by linking a transplant register to hospital admission, notifiable diseases, and death register in 4858 solid organ transplant recipients in New South Wales, Australia. They found an excess of influenza and invasive pneumococcal disease when compared with the general population, with a standardized incidence ratio, relative to the general population, of 8.5 (95% confidence interval, 7.8–9.2) for influenza and 9.8 (95% confidence interval, 6.9–13.9) for invasive pneumococcal disease. Both were associated with a high hospitalization rate and some mortality, and both are potentially preventable. Data on vaccination status were not available in this study, but it is reasonable to postulate that some of the episodes would have been avoidable. A similar study conducted in the Swiss Transplant Cohort Study found 593 of 4967 (11.9%) solid organ recipients with a vaccine-preventable disease.3 By linkage of medical records in 4 counties in southeastern Minnesota, Felzer et al4 reported vaccination rates of 57% to 63% for influenza and 56% for pneumococcal vaccines in 468 solid organ transplant recipients. In this study, rurality was one of the reasons for undervaccination. With <50% of all transplanted patients having the recommended vaccinations, optimizing uptake is surely possible. In the current issue of Transplantation, Javaid et al5 report on the seroprevalence of measles, mumps, rubella, and varicella zoster virus (MMRV) and assess the seroresponse to vaccination. The study was retrospectively conducted on candidates for solid organ transplantation. Of 1213 patients included, 394 (12%) had at least 1 negative serology to MMRV. Negativity was evenly distributed between the 4 viruses. Older age and listing for liver transplantation were associated with a positive serology to all 4 pathogens, whereas a previous history of solid organ transplantation and being on the list for pancreas/kidney transplantation were independent factors of at least 1 negative serology. Out of the seronegative patients, only 60 received an MMR or varicella vaccine, and of these, the response was assessed in 37 patients, of whom 13 (35%) did not seroconvert. What can we learn from this? First, a relevant number of candidates have a negative serology for MMRV. Second, even with a screening program in place, following up on patients with a negative serology is a challenge, even more so if the success of vaccination needs to be confirmed. This is very similar to other vaccine-preventable diseases. Protection would, in particular, be important for varicella zoster virus and measles, in which morbidity and mortality can be considerable. Finally, one shot might not be enough to elicit a response; therefore, it might be necessary to assess the serology and repeat the vaccination. MMR and varicella zoster vaccination (for seronegative patients) is done with live vaccines and formally contraindicated after transplantation, highlighting the importance of this window of opportunity to administer these vaccines before transplantation. The same is also true for any other (nonlive) vaccine, as the immune response, even if decreased by the underlying disease leading to transplantation, is still stronger before immunosuppression than after transplantation. Why then do we fail to implement a successful vaccination strategy, an intervention with a high leverage? The reasons are not entirely clear. Given the high exposure to healthcare of these patients, one would think that there are ample occasions to update vaccinations. It may be that the emphasis in the past has been on the posttransplant period, somewhat neglecting the possibilities of infectious diseases counseling and prevention in the pretransplant period. With all the decisions, questions, and concerns facing our patients, this issue is not at the top of the list. The available data clearly indicate a gap in care, which is systematic and present across all programs and geographic eras. One way to go forward is to develop a systematic approach tailored to the specifics of the individual programs. The beneficial impact of such an approach was demonstrated by Blanchard-Rohner et al.6 They demonstrated a remarkable improvement in the vaccination status after introducing a regular workup in all candidates. Ideally, such a pretransplant workup should not only focus on vaccination, but could also be used to screen for additional latent infections, inform patients about the options of prevention, and start some education on posttransplant safe living strategies. As always, implementation is a challenge, but in view of the impact, a worthwhile investment.
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