Case report: Clearance of longstanding, immune-deficiency-associated, vaccine-derived polio virus infection following remdesivir therapy for chronic SARS-CoV-2 infection

Toward Personalized Medicine: The Effect of Treatment of Chronic Enterovirus Diarrhea in an Immunocompromised Patient and the Correlation With In Vitro Models

Enteroviruses (EV) usually cause acute, mild, self-limiting disease. Chronic infections with EVs are rare, and typically occur in patients with immunodeficiency, posing a high risk of severe outcomes. We report a rare case of chronic diarrhea caused by coxsackievirus A1 (CVA1) (from EV-C species) infection in a patient with a common variable immunodeficiency, who was on treatment with pooled intravenous immunoglobulin (IVIG) from the Netherlands. To explore treatment options, we assessed the presence of neutralizing antibodies (nAbs) against CVA1 in pooled IVIG from South Africa, where EV-Cs are prevalent, and tested the antiviral efficacy of US Food and Drug Administration-approved drugs like fluoxetine, itraconazole, ribavirin, and remdesivir (RDV) against CVA1 in vitro. Both Dutch and South African IVIG showed low nAb titers against CVA1. The patient, treated with Dutch IVIG, also received a combination of amantadine and fluoxetine, which were discontinued due to side effects. Among the drugs tested, only RDV significantly inhibited CVA1 replication in rhabdomyosarcoma (RD) cells. This in vitro efficacy was not reflected by a favorable clinical response after treatment of the patient with RDV. In concordance with unfavorable antiviral response in the patient, preliminary tests on a co-culture model containing isogenic human intestinal cells and intestinal fibroblasts showed no significant reduction in CVA1 RNA copies after RDV administration. In conclusion, our results showed that repurposing of drugs that have shown in vitro efficacy does not translate well to the patients, and this is also reflected in a more physiologically relevant model of the human intestine.

COVID-19 infection in inborn errors of immunity and their phenocopies: a systematic review and meta-analysis

BACKGROUND

Inborn errors of immunity (IEI) are congenital disorders of the immune system. Due to impaired immune system, they are at a higher risk to develop a more severe COVID-19 course compared to general population.

OBJECTIVES

Herein, we aimed to systematically review various aspects of IEI patients infected with SARS-CoV-2. Moreover, we performed a meta-analysis to determine the frequency of COVID-19 in patients with different IEI.

METHODS

Embase, Web of Science, PubMed, and Scopus were searched introducing terms related to IEI and COVID-19.

RESULTS

3646 IEI cases with a history of COVID-19 infection were enrolled. The majority of patients had critical infections (1013 cases, 27.8%). The highest frequency of critical and severe cases was observed in phenocopies of IEI (95.2%), defects in intrinsic and innate immunity (69.4%) and immune dysregulation (23.9%). 446 cases (12.2%) succumbed to the disease and the highest mortality was observed in IEI phenocopies (34.6%). COVID-19 frequency in immunodeficient patients was 11.9% (95% CI: 8.3 to 15.5%) with innate immunodeficiency having the highest COVID-19 frequency [34.1% (12.1 to 56.0%)]. COVID-19 case fatality rate among IEI patients was estimated as 5.4% (95% CI: 3.5-8.3%, n = 8 studies, I2 = 17.5%).

CONCLUSION

IEI with underlying defects in specific branches of the immune system responding to RNA virus infection experience a higher frequency and mortality of COVID-19 infection. Increasing awareness about these entities and underlying genetic defects, adherence to prophylactic strategies and allocating more clinical attention to these patients could lead to a decrease in COVID-19 frequency and mortality in these patients.

Characterization of environmental and clinical surveillance inputs to support prospective integrated modeling of the polio endgame

National, regional, and global poliovirus surveillance needs continue to expand and evolve. The 1988 global resolution to eradicate polio necessitated the creation and support for a global poliovirus surveillance system able to identify poliovirus transmission anywhere and everywhere. Clinical surveillance of patients that present with acute flaccid paralysis (AFP) became an essential tool, and the need for standardized laboratory methods to detect polioviruses isolated from stool samples of AFP patients led to the development of the Global Poliovirus Laboratory Network (GPLN) in 1990. Relatively recently, the GPLN expanded to include environmental surveillance to obtain additional information about poliovirus transmission in some geographies and to increase confidence about the absence of poliovirus transmission after successful eradication and/or the cessation of use of live-attenuated oral poliovirus vaccines (OPVs). Historical polio eradication strategic plans anticipated that successful global poliovirus eradication would lead to reduced requirements for financial investments for a poliovirus-specific surveillance system, and consequent transition of capacity and resources into integrated national disease surveillance systems. However, given the state of the polio endgame with ongoing transmission in several geographies, current global strategic plans include poliovirus-specific surveillance for the foreseeable future. In addition, the development and expansion of genetic testing technologies create new opportunities for poliovirus surveillance system designs. The expected growth (instead of decline) of poliovirus surveillance needs as of 2024, as well as innovations in laboratory technologies and expansion wastewater sampling, raise questions about the tradeoffs of different options and the future of poliovirus surveillance. This descriptive review of poliovirus surveillance evidence as of late 2024 aims to provide national, regional, and global decision makers with an understanding of prospective tradeoffs and uncertainties and to support prospective assumptions relevant for integrated policy, poliovirus transmission, and economic modeling for 2024-2035.

Immunodeficiency-Related Vaccine-Derived Poliovirus (iVDPV) Infections: A Review of Epidemiology and Progress in Detection and Management

Individuals with certain primary immunodeficiency disorders (PID) may be unable to clear poliovirus infection after exposure to oral poliovirus vaccine (OPV). Over time, vaccine-related strains can revert to immunodeficiency-associated vaccine-derived poliovirus (iVDPVs) that can cause paralysis in the patient and potentially spread in communities with low immunity. We reviewed the efforts for detection and management of PID patients with iVDPV infections and the epidemiology through an analysis of 184 cases reported to the World Health Organization (WHO) during 1962-2024 and a review of polio program and literature reports. Most iVDPV patients (79%) reported in the WHO Registry were residents in middle-income countries and almost half (48%) in the Eastern Mediterranean Region. Type 2 iVDPV was most frequently isolated (53%), but a sharp decline was observed after the switch to bivalent OPV in 2016, with only six cases reported during 2017-2024 compared to 63 during 2009-2016. Patients with common variable immunodeficiency have longer excretion of iVDPV than with other PID types. Implementation of sensitive sentinel surveillance to detect cases of iVDPV infection in high-risk countries and offer antiviral treatment to patients is challenged by competition with other health priorities and regulatory hurdles to the compassionate use of investigational antiviral drugs.

The multiple roles of viral 3Dpol protein in picornavirus infections

The Picornaviridae are a large group of positive-sense, single-stranded RNA viruses, and most research has focused on the Enterovirus genus, given they present a severe health risk to humans. Other picornaviruses, such as foot-and-mouth disease virus (FMDV) and senecavirus A (SVA), affect agricultural production with high animal mortality to cause huge economic losses. The 3Dpol protein of picornaviruses is widely known to be used for genome replication; however, a growing number of studies have demonstrated its non-polymerase roles, including modulation of host cell biological processes, viral replication complex assembly and localization, autophagy, and innate immune responses. Currently, there is no effective vaccine to control picornavirus diseases widely, and clinical therapeutic strategies have limited efficiency in combating infections. Many efforts have been made to develop different types of drugs to prohibit virus survival; the most important target for drug development is the virus polymerase, a necessary element for virus replication. For picornaviruses, there are also active efforts in targeted 3Dpol drug development. This paper reviews the interaction of 3Dpol proteins with the host and the progress of drug development targeting 3Dpol.

Health Economic Analysis of Antiviral Drugs in the Global Polio Eradication Endgame

BACKGROUND

Polio antiviral drugs (PAVDs) may provide a critical tool in the eradication endgame by stopping poliovirus infections in immunodeficient individuals who may not clear the virus without therapeutic intervention. Although prolonged/chronic poliovirus excreters are rare, they represent a source of poliovirus reintroduction into the general population. Prior studies that assumed the successful cessation of all oral poliovirus vaccine (OPV) use estimated the potential upper bound of the incremental net benefits (INBs) of resource investments in research and development of PAVDs. However, delays in polio eradication, OPV cessation, and the development of PAVDs necessitate an updated economic analysis to reevaluate the costs and benefits of further investments in PAVDs.

METHODS

Using a global integrated model of polio transmission, immunity, vaccine dynamics, risks, and economics, we explore the risks of reintroduction of polio transmission due to immunodeficiency-related vaccine-derived poliovirus (iVDPV) excreters and reevaluate the upper bound of the INBs of PAVDs.

RESULTS

Under the current conditions, for which the use of OPV will likely continue for the foreseeable future, even with successful eradication of type 1 wild poliovirus by the end of 2023 and continued use of Sabin OPV for outbreak response, we estimate an upper bound INB of 60 million US$2019. With >100 million US$2019 already invested in PAVD development and with the introduction of novel OPVs that are less likely to revert to neurovirulence, our analysis suggests the expected INBs of PAVDs would not offset their costs.

CONCLUSIONS

While PAVDs could play an important role in the polio endgame, their expected economic benefits drop with ongoing OPV use and poliovirus transmissions. However, stakeholders may pursue the development of PAVDs as a desired product regardless of their economic benefits.HighlightsWhile polio antiviral drugs could play an important role in the polio endgame, their expected economic benefits continue to drop with delays in polio eradication and the continued use of oral poliovirus vaccines.The incremental net benefits of investments in polio antiviral drug development and screening for immunodeficiency-related circulating polioviruses are small.Limited global resources are better spent on increasing global population immunity to polioviruses to stop and prevent poliovirus transmission.

The Fight against Poliovirus Is Not Over

Poliovirus (PV), the virus that causes both acute poliomyelitis and post-polio syndrome, is classified within the Enterovirus C species, and there are three wild PV serotypes: WPV1, WPV2 and WPV3. The launch of the Global Polio Eradication Initiative (GPEI) in 1988 eradicated two of the three serotypes of WPV (WPV2 and WPV3). However, the endemic transmission of WPV1 persists in Afghanistan and Pakistan in 2022. There are cases of paralytic polio due to the loss of viral attenuation in the oral poliovirus vaccine (OPV), known as vaccine-derived poliovirus (VDPV). Between January 2021 and May 2023, a total of 2141 circulating VDPV (cVDPV) cases were reported in 36 countries worldwide. Because of this risk, inactivated poliovirus (IPV) is being used more widely, and attenuated PV2 has been removed from OPV formulations to obtain bivalent OPV (containing only types 1 and 3). In order to avoid the reversion of attenuated OPV strains, the new OPV, which is more stable due to genome-wide modifications, as well as sabin IPV and virus-like particle (VLP) vaccines, is being developed and offers promising solutions for eradicating WP1 and VDPV.