The use of Vaccinia Immune Globulin in the Treatment of Severe Mpox. Virus Infection in Human Immunodeficiency Virus/AIDS.

We report a case of progressive, severe mpox virus (MPXV) infection in a patient with AIDS despite a standard course of tecovirimat. He significantly improved after administration of vaccinia immune globulin intravenous (VIGIV) highlighting its use as an adjunct for severe disease in immunocompromised hosts.

Novel Treatment of a Vaccinia Virus Infection from an Occupational Needlestick - San Diego, California, 2019.

Vaccinia virus (VACV) is an orthopoxvirus used in smallpox vaccines, as a vector for novel cancer treatments, and for experimental vaccine research (1). The Advisory Committee on Immunization Practices (ACIP) recommends smallpox vaccination for laboratory workers who handle replication-competent VACV (1). For bioterrorism preparedness, the U.S. government stockpiles tecovirimat, the first Food and Drug Administration-approved antiviral for treatment of smallpox (caused by variola virus and globally eradicated in 1980*,†) (2). Tecovirimat has activity against other orthopoxviruses and can be administered under a CDC investigational new drug protocol. CDC was notified about an unvaccinated laboratory worker with a needlestick exposure to VACV, who developed a lesion on her left index finger. CDC and partners performed laboratory confirmation, contacted the study sponsor to identify the VACV strain, and provided oversight for the first case of laboratory-acquired VACV treated with tecovirimat plus intravenous vaccinia immunoglobulin (VIGIV). This investigation highlights 1) the misconception among laboratory workers about the virulence of VACV strains; 2) the importance of providing laboratorians with pathogen information and postexposure procedures; and 3) that although tecovirimat can be used to treat VACV infections, its therapeutic benefit remains unclear.

CD69 Targeting Enhances Anti-vaccinia Virus Immunity.

CD69 is highly expressed on the leukocyte surface upon viral infection, and its regulatory role in the vaccinia virus (VACV) immune response has been recently demonstrated using CD69-/- mice. Here, we show augmented control of VACV infection using the anti-human CD69 monoclonal antibody (MAb) 2.8 as both preventive and therapeutic treatment for mice expressing human CD69. This control was related to increased natural killer (NK) cell reactivity and increased numbers of cytokine-producing T and NK cells in the periphery. Moreover, similarly increased immunity and protection against VACV were reproduced over both long and short periods in anti-mouse CD69 MAb 2.2-treated immunocompetent wild-type (WT) mice and immunodeficient Rag2-/- CD69+/+ mice. This result was not due to synergy between infection and anti-CD69 treatment since, in the absence of infection, anti-human CD69 targeting induced immune activation, which was characterized by mobilization, proliferation, and enhanced survival of immune cells as well as marked production of several innate proinflammatory cytokines by immune cells. Additionally, we showed that the rapid leukocyte effect induced by anti-CD69 MAb treatment was dependent on mTOR signaling. These properties suggest the potential of CD69-targeted therapy as an antiviral adjuvant to prevent derived infections.IMPORTANCE In this study, we demonstrate the influence of human and mouse anti-CD69 therapies on the immune response to VACV infection. We report that targeting CD69 increases the leukocyte numbers in the secondary lymphoid organs during infection and improves the capacity to clear the viral infection. Targeting CD69 increases the numbers of gamma interferon (IFN-γ)- and tumor necrosis factor alpha (TNF-α)-producing NK and T cells. In mice expressing human CD69, treatment with an anti-CD69 MAb produces increases in cytokine production, survival, and proliferation mediated in part by mTOR signaling. These results, together with the fact that we have mainly worked with a human-CD69 transgenic model, reveal CD69 as a treatment target to enhance vaccine protectiveness.

Smallpox vaccine complications: the dermatologist's role in diagnosis and management.

In 2002, the United States implemented a new program for smallpox vaccinations among military personnel using a live vaccinia virus product. Approximately 2.4 million US military service members and health care workers have since been inoculated, with considerable numbers experiencing adverse reactions. Military dermatologists are at the forefront of describing and treating these reactions, from relatively benign generalized vaccinia (GV) and erythema multiforme (EM) to more severe progressive vaccinia (PV) and eczema vaccinatum (EV). A wide range of providers, including civilian dermatologists and primary care providers, also may see such reactions and must be aware of the spectrum of vaccine reactions. Given current world instability (eg, threats of nuclear war, rise of authoritarian regimes) and concerns for bioterrorism attacks, the smallpox vaccine program likely will continue indefinitely. As the brisk military deployment tempo continues, a larger population of new vaccinees will yield more cutaneous reactions and diagnostic challenges.

Development of an animal model of progressive vaccinia in nu/nu mice and the use of bioluminescence imaging for assessment of the efficacy of monoclonal antibodies against vaccinial B5 and L1 proteins.

Bioluminescence imaging (BLI) was used to follow dissemination of recombinant vaccinia virus (VACV) expressing luciferase (IHD-J-Luc) in BALB/c nu/nu mice treated post-challenge with monoclonal antibodies (MAbs) against L1 and B5 VACV proteins in a model of Progressive Vaccinia (PV). Areas Under the flux Curve (AUC) were calculated for viral loads in multiple organs in individual mice. Following scarification with 105 pfu, IHD-J-Luc VACV undergoes fast replication at the injection site and disseminates rapidly to the inguinal lymph nodes followed by spleen, liver, and axillary lymph nodes within 2-3 days and before primary lesions are visible at the site of scarification. Extension of survival in nude mice treated with a combination of anti-B5 and anti-L1 MAbs 24 h post challenge correlated with a significant reduction in viral load at the site of scarification and delayed systemic dissemination. Nude mice reconstituted with 104 T cells prior to challenge with IHD-J-Luc, and treated with MAbs post-challenge, survived infection, cleared the virus from all organs and scarification site, and developed anti-VACV IgG and VACV-specific polyfunctional CD8+ T cells that co-expressed the degranulation marker CD107a, and IFNγ and TNFα cytokines. All T cell reconstituted mice survived intranasal re-challenge with IHD-J-Luc (104 pfu) two months after the primary infection. Thus, using BLI to monitor VACV replication in a PV model, we showed that anti-VACV MAbs administered post challenge extended survival of nude mice and protected T cell reconstituted nude mice from lethality by reducing replication at the site of scarification and systemic dissemination of VACV.

Daily ingestion of the probiotic Lactobacillus paracasei ST11 decreases Vaccinia virus dissemination and lethality in a mouse model.

Vaccinia virus (VACV) is an important pathogen. Although studies have shown relationships between probiotics and viruses, the effect of probiotics on VACV infection is unknown. Therefore, this work aims to investigate the probiotics effects on VACV infection. Mice were divided into four groups, two non-infected groups, one receiving the probiotic, the other one not receiving it, and two groups infected intranasally with VACV Western Reserve (VACV-WR) receiving or not receiving the probiotic. Viral titres in organs and cytokine production in the lungs were analysed. Lung samples were also subjected to histological analysis. The intake of probiotic results in reduction in viral spread with a significant decrease of VACV titer on lung, liver and brain of treated group. In addition,treatment with the probiotic results in attenuated mice lung inflammation showing fewer lesions on histological findings and decreased lethality in mice infected with VACV. The ingestion of Lactobacillus paracasei ST11 (LPST11) after VACV infection resulted in 2/9 animal lethality compared with 4/9 in the VACV group. This is the first study on probiotics and VACV interactions, providing not only information about this interaction, but also proposing a model for future studies involving probiotics and other poxvirus.

Effects of postchallenge administration of ST-246 on dissemination of IHD-J-Luc vaccinia virus in normal mice and in immune-deficient mice reconstituted with T cells.

Whole-body bioimaging was used to study dissemination of vaccinia virus (VACV) in normal and in immune deficient (nu(-)/nu(-)) mice protected from lethality by postchallenge administration of ST-246. Total fluxes were recorded in the liver, spleen, lungs, and nasal cavities of live mice after intranasal infection with a recombinant IHD-J-Luc VACV expressing luciferase. Areas under the flux curve were calculated for individual mice to assess viral loads. Treatment for 2 to 5 days of normal BALB/c mice with ST-246 at 100 mg/kg starting 24 h postchallenge conferred 100% protection and reduced viral loads in four organs compared to control mice. Mice also survived after 5 days of treatment with ST-246 at 30 mg/kg, and yet the viral loads and poxes were higher in these mice compared to 100-mg/kg treatment group. Nude mice were not protected by ST-246 alone or by 10 million adoptively transferred T cells. In contrast, nude mice that received T cells and 7-day treatment with ST-246 survived infection and exhibited reduced viral loads compared to nonreconstituted and ST-246-treated mice after ST-246 was stopped. Similar protection of nude mice was achieved using adoptively transferred 1.0 and 0.1 million, but not 0.01 million, purified T cells or CD4(+) or CD8(+) T cells in conjunction with ST-246 treatment. These data suggest that ST-246 protects immunocompetent mice from lethality and reduces viral dissemination in internal organs and poxvirus lesions. Furthermore, immune-deficient animals with partial T cell reconstitution can control virus replication after a course of ST-246 and survive lethal vaccinia virus challenge.

Preferential replication of systemically delivered oncolytic vaccinia virus in focally irradiated glioma xenografts.

PURPOSE: Radiotherapy is part of the standard of care in high-grade gliomas but its outcomes remain poor. Integrating oncolytic viruses with standard anticancer therapies is an area of active investigation. The aim of this study was to determine how tumor-targeted ionizing radiation (IR) could be combined with systemically delivered oncolytic vaccinia virus. EXPERIMENTAL DESIGN: U-87 glioma xenografts were grown subcutaneously or orthotopically. Oncolytic vaccinia viruses GLV-1h68 and LIVP 1.1.1 were injected systemically and IR was given focally to glioma xenografts. In a bilateral tumor model, glioma xenografts were grown in both flanks, oncolytic vaccinia was injected systemically and radiation was delivered specifically to the right flank tumor, whereas the left flank tumor was shielded. Viral replication and tumor regression, after systemic injection, was analyzed and compared in irradiated and nonirradiated glioma xenografts. RESULTS: Systemically administered oncolytic vaccinia virus replicated to higher titers in preirradiated U-87 xenografts than in nonirradiated glioma xenografts. This increased oncolytic viral replication correlated with increased tumor xenograft regression and mouse survival in subcutaneous and orthotopic U-87 glioma models compared with monotherapies. The ability of focal IR to mediate selective replication of oncolytic vaccinia was shown in a bilateral glioma model in which systemically administered oncolytic vaccinia replicated preferentially in the irradiated tumor compared with the nonirradiated tumor in the same mouse. CONCLUSION: These findings show a potential clinical role of focal IR in sensitizing irradiated tumor sites for preferential vaccinia virus-mediated oncolysis.

The poxvirus A35 protein is an immunoregulator.

It was shown previously that the highly conserved vaccinia virus A35 gene is an important virulence factor in respiratory infection of mice. We show here that A35 is also required for full virulence by the intraperitoneal route of infection. A virus mutant in which the A35 gene has been removed replicated normally and elicited improved antibody, gamma interferon-secreting cell, and cytotoxic T-lymphocyte responses compared to wild-type virus, suggesting that A35 increases poxvirus virulence by immunomodulation. The enhanced immune response correlated with an improved control of viral titers in target organs after the development of the specific immune response. Finally, the A35 deletion mutant virus also provided protection from lethal challenge (1,000 50% lethal doses) equal to that of the wild-type virus. Together, these data suggest that A35 deletion viruses will make safer and more efficacious vaccines for poxviruses. In addition, the A35 deletion viruses will serve as improved platform vectors for other infectious diseases and cancer and will be superior vaccine choices for postexposure poxvirus vaccination, as they also provide improved kinetics of the immune response.

Household transmission of vaccinia virus from contact with a military smallpox vaccinee--Illinois and Indiana, 2007.

On March 7, 2007, the Chicago Department of Public Health and the University of Chicago Pediatric Infectious Disease Service and Infection Control Program notified CDC of a child with presumed eczema vaccinatum (EV), a life-threatening complication of vaccinia virus infection. This is the first reported EV case in the United States since 1988. This report summarizes the epidemiologic and environmental investigations conducted by local, state, and federal public health authorities in Illinois and Indiana to determine the source of exposure and to identify and monitor other persons at risk for vaccinia virus infection. This case highlights the need for clinicians to maintain a high index of suspicion when evaluating recently vaccinated patients and their family members with vesiculopustular rash.

Vaccinia immune globulin: current policies, preparedness, and product safety and efficacy.

In 1980 the World Health Organization declared that smallpox was eradicated from the world, and routine smallpox vaccination was discontinued. Nevertheless, samples of the smallpox virus (variola virus) were retained for research purposes, not least because of fears that terrorist groups or rogue states might also have kept samples in order to develop a bioweapon. Variola virus represents an effective bioweapon because it is associated with high morbidity and mortality and is highly contagious. Since September 11, 2001, countries around the world have begun to develop policies and preparedness programs to deal with a bioterror attack, including stockpiling of smallpox vaccine. Smallpox vaccine itself may be associated with a number of serious adverse events, which can often be managed with vaccinia immune globulin (VIG). VIG may also be needed as prophylaxis in patients for whom pre-exposure smallpox vaccine is contraindicated (such as those with eczema or pregnant women), although it is currently not licensed in these cases. Two intravenous formulations of VIG (VIGIV Cangene and VIGIV Dynport) have been licensed by the FDA for the management of patients with progressive vaccinia, eczema vaccinatum, severe generalized vaccinia, and extensive body surface involvement or periocular implantation following inadvertent inoculation.

Biological activity of an intravenous preparation of human vaccinia immune globulin in mouse models of vaccinia virus infection.

The biological activity of a new intravenous (i.v.) preparation of human vaccinia immune globulin (VIGIV) was evaluated in two mouse models of vaccinia virus (VV) infection. In a mouse tail lesion model, female CD-1 mice were inoculated i.v. with 7 x 10(4) PFU of VV to produce >10 lesions per tail 8 days later. In a mouse lethality model, female severe combined immunodeficient (SCID) mice were inoculated i.v. with 3 x 10(4) PFU of VV to produce 100% mortality within 45 days. The ability of VIGIV to reduce tail lesion formation in CD-1 mice and mortality in SCID mice was determined by (i) pretreatment of a lethal VV dose with VIGIV prior to i.v. inoculation into SCID mice and (ii) i.v. administration of VIGIV to CD-1 and SCID mice the day before and up to 8 days after VV infection. VIGIV reduced the proportion of CD-1 mice with >10 tail lesions in a dose-related manner when VIGIV was given 1 day before and up to 1 day after VV inoculation. The pretreatment of VV with VIGIV prolonged survival and decreased mortality. VIGIV (100 and 400 mg/kg) prolonged survival when given up to 4 days after VV inoculation, and the 400-mg/kg dose reduced the mortality rate by 80% when given the day before or immediately after VV inoculation. The biological activity of VIGIV was demonstrated in both the immunocompetent and immunocompromised murine models. The timing of treatment relative to VV inoculation appeared to be important for the demonstration of VIGIV's biological activity.

Safety and pharmacokinetic evaluation of intravenous vaccinia immune globulin in healthy volunteers.

BACKGROUND: Vaccinia immune globulin (VIG) administered via the intramuscular route has historically been used for the treatment of complications of smallpox vaccination. Intravenous formulations of VIG are required to improve tolerability and pharmacokinetic profile. METHODS: We conducted 2 separate studies to evaluate the feasibility of administration of an intravenous formulation of antivaccinia immune globulin (VIGIV). The first study assessed the pharmacokinetics and safety of a newly manufactured lyophilized VIG product for intravenous administration (VIGIV-lyo). Seventy-eight healthy volunteers received an intravenous infusion of VIGIV-lyo at doses of 100 mg/kg, 200 mg/kg, or 500 mg/kg. In the second study, we evaluated the safety of a liquid product of VIGIV (VIGIV-liq) in 33 healthy volunteers receiving an intravenous infusion of 100 mg/kg VIGIV-liq. RESULTS: The geometric mean titer of VIG at the target dose (100 mg/kg) after intravenous administration is 2.5 times higher than the predicted geometric mean titer after intramuscular injection (P<.001). The pharmacokinetics of VIGIV-lyo are linear for doses from 100 mg/kg through 500 mg/kg. Administration of the 200-mg/kg and 500-mg/kg doses of VIGIV-lyo does not result in markedly higher adverse event rates. The adverse event rates observed with the liquid product are comparable to those seen with the lyophilized product. CONCLUSIONS: These 2 studies suggest that intravenous administration of VIG is well tolerated and results in a more favorable pharmacokinetic profile than does VIG administered intramuscularly.

Clinical efficacy of intramuscular vaccinia immune globulin: a literature review.

BACKGROUND: Numerous literature reports describe clinical efficacy of intramuscular vaccinia immune globulin (VIG) for complications of smallpox vaccination, prophylaxis of individuals with contraindications to vaccination, and prevention of smallpox among close contacts of patients with smallpox. METHODS: We reviewed the literature regarding VIG treatment and prophylaxis of smallpox vaccine complications and the use of VIG as a preventative measure for close contacts of patients with smallpox. RESULTS: Data regarding intramuscular administration of VIG for treatment of smallpox vaccine complications occurred in 16 articles, none of which reported formal controlled trials. The indications for treatment include generalized vaccinia, progressive vaccinia, eczema vaccinatum, and certain accidental implantations. Six publications suggest VIG efficacy for prophylaxis of vaccinial superinfection of eczema, burns, chickenpox, immunosuppression, pregnancy, or certain skin conditions. Prophylactic VIG has also been used in healthy military recruits to reduce the incidence of postvaccinial encephalitis. The use of intramuscular administration of VIG to prevent smallpox in contacts of patients with documented cases of smallpox is reported in 4 studies that compare contacts who received intramuscular administration of VIG with those who did not and in 1 observational study, with varying but promising results. CONCLUSIONS: Although controlled clinical trials do not exist to support the use of VIG for treatment of vaccinia-related complications or prophylaxis among individuals with contraindications to smallpox vaccination, available data suggest that VIG reduces morbidity and mortality associated with progressive vaccinia (vaccinia necrosum) and eczema vaccinatum. Furthermore, VIG seems to prevent vaccinial superinfection in patients with inflammatory skin diseases or burns, given the low incidence of vaccina-related complications associated with these conditions.

Emergency medicine tools to manage smallpox (vaccinia) vaccination complications: clinical practice guideline and policies and procedures.

In December 2002, the federal government began a program to immunize approximately 500000 civilian public health and health care workers with smallpox (vaccinia) vaccine as a part of our pre-event defense against bioterrorism. First responders will likely follow, and the general US population might be offered vaccination in the next 1 to 2 years. Recent reports that suggest the possible association of the vaccine to adverse cardiac events (including deaths), liability concerns for hospitals, and the availability of compensation for workers with vaccine complications have significantly reduced voluntary participation. Vaccinees might experience robust primary takes or serious adverse events, including viral or even bacterial cellulitides, encephalitis, progressive skin destruction, and other life-threatening complications. With the increasing prevalence of immune suppression from both diseases and immunosuppressive medications, complications might be seen in higher frequency than previously reported. Emergency medicine providers and staff must become familiar with clinical presentations and management of vaccine complications. In addition, policies and procedures must be developed to prevent unimmunized providers from inadvertently contacting the active vaccination sites of their patients and, if the providers themselves have active vaccination sites, to protect their patients and their own families.

Adverse events occurring after smallpox vaccination.

We reviewed the literature on adverse events reported to occur after smallpox vaccination. Nearly one-half of the United States population is vaccinia-naïve and may be at risk for development of serious adverse events. We describe the clinical features of postvaccinial central nervous system disease, progressive vaccinia, eczema vaccinatum, accidental implantations, "generalized vaccinia," and the common erythematous and/or urticarial rashes. In the 1960s, death occurred approximately once in every million primary vaccinations, with fatalities resulting from progressive vaccinia, postvaccinial encephalitis, and eczema vaccinatum. Death in revaccinees occurred less commonly and almost entirely from progressive vaccinia. In today's population, death rates might be higher because of the increased prevalence of immune deficiency and atopic dermatitis.

Administration to mice of a monoclonal antibody that neutralizes the intracellular mature virus form of vaccinia virus limits virus replication efficiently under prophylactic and therapeutic conditions.

The WHO smallpox eradication program was concluded 21 years ago and the non-vaccinated population is now at risk of poxvirus infections, either by contact with monkeypox or through bioterrorism. Since drugs specific against poxvirus infections are limited, neutralizing monoclonal antibodies (mAbs) that are effective in vivo may be an important tool in controlling poxvirus infections. To this end, we studied the efficacy of the mAb C3, reactive against the trimeric 14-kDa protein of vaccinia virus (VV) localized in the membrane of the intracellular form of mature virus, for its ability to neutralize VV infection in mice. The results show that prophylactic as well as therapeutic administration of mAb C3 can be an effective means of control of VV replication within the host. The interval of antibody efficacy following a single administration, before and after VV inoculation, has been defined. This study reinforces the notion that neutralizing mAbs should be developed to control health-related human infections by poxviruses.