Povidone Iodine Ointment Application to the Vaccination Site Does Not Alter Immunoglobulin G Antibody Response to Smallpox Vaccine

Abstract

U.S. military personnel deployed to high-risk areas receive the live vaccinia virus (VACV) smallpox vaccine ACAM2000. VACV shedding from the vaccination site can result in autoinoculation and contact transmission. We previously found that the application of povidone iodine ointment (PIO) to the scarification site reduced viral shedding without altering the antibody response, as measured by plaque reduction neutralization or enzyme-linked immunosorbent assays. In this study, we used protein microarray assays to measure the amount of immunoglobulin G antibody bound to (1) ACAM2000 itself and (2) individual VACV antigens that are present within ACAM2000. We assessed antibody binding in sera from primary smallpox vaccinees who applied PIO to the scarification site beginning on day 7 (PIO group) and from those who did not apply PIO (control group). In both cohorts, the postvaccination antibody response-in terms of antibody binding, both to ACAM2000 and to 11 individual VACV antigens-was significantly greater than the prevaccination response (all p < 0.0001). The postvaccination antibody binding levels of vaccinees in the PIO group did not differ from those of control vaccinees. These findings further support the topical application of PIO, starting on day 7, to reduce the viral shedding associated with smallpox vaccination.

Changes in a new type of genomic accordion may open the pallets to increased monkeypox transmissibility

“…Inactivation of OPG153 genes by frameshift mutations occurs rapidly in experimental orthopoxvirus evolution models (Senkevich et al ., 2020), resulting increased virus replication levels, changes in particle morphogenesis, decreased particle-to-PFU ratios, and differences in pathogenesis (Kastenmayer et al ., 2014; Senkevich et al ., 2020). Finally, A26L is the main target of the host antibody response to orthopoxvirus infection (Keasey et al, 2010; Pugh et al, 2016). Thus, any genomic change that modulates OPG153 is likely of significance.…”

“…There are several lines of evidence that mark this ORF as a significant factor in transmission and virulence among OPXV: (1) OPG153 is a known attachment factor (to laminin) for OPXV 116,117 ; (2) OPG153 is a significant factor regulating egress for OPXV 116,118–120 ; (3) In a comparative genomic analysis of poxviruses, OPG153 is unique by being the “core” gene that has been “lost” the most times during poxvirus evolution 36 ; (4) during experimental evolution experiments, inactivation of OPG153 genes by frameshift mutations provided rapid adaptation in a poxviral model 40 . These changes resulted in increased virus replication levels, changes in morphogenesis quantified by EM, in decreased particle/PFU ratios 40 and differences in pathogenesis 119 ; and (5) Advanced dissection of the adaptive immune response against MPXV demonstrated that OPG153 is the main target of the antibody response 121,122 .…”