Use of a reduced (4-dose) vaccine schedule for postexposure prophylaxis to prevent human rabies-recommendations of the Advisory Committee on Immunization Practice

Generation of therapeutic antisera for emerging viral infections

The recent Ebola virus outbreak has highlighted the therapeutic potential of antisera and renewed interest in this treatment approach. While human convalescent sera may not be readily available in the early stages of an outbreak, antisera of animal origin can be produced in a short time frame. Here, we compared adjuvanted virus-like particles (VLP) with recombinant modified vaccinia virus Ankara and vesicular stomatitis virus (VSV), both expressing the Ebola virus antigens. The neutralizing antibody titers of rabbits immunized with adjuvanted VLPs were similar to those immunized with the replication-competent VSV, indicating that presentation of the antigen in its native conformation rather than de novo antigen expression is essential for production of functional antibodies. This approach also yielded high-titer antisera against Nipah virus glycoproteins, illustrating that it is transferable to other virus families. Multiple-step immunoglobulin G purification using a two-step 20–40% ammonium sulfate precipitation followed by protein A affinity chromatography resulted in 90% recovery of functionality and sustained in vivo stability. Adjuvanted VLP-based immunization strategies are thus a promising approach for the rapid generation of therapeutic antisera against emerging infections.

Passive immunity through the transfer of anti-serum represents the earliest clinical application of antibodies and is still widely used to this day in the form of anti-venoms. Veronika von Messling and colleagues at the Paul Ehrlich Institute investigate the potential of generating neutralizing anti-serum to the emerging viruses Ebola and Nipah. The authors compare different vaccination platforms in mice and rabbits and find that following multiple vaccine challenges, neutralizing antibody titers equivalent to that seen in convalescent patients could be obtained. Purification of the IgG fraction and processing into F(ab’)₂ fragments has the potential to significantly reduce xeno-responses yet the authors find that neutralizing capacity is largely retained albeit at the cost of a shorter in vivo half-life. These findings offer the hope of rapidly generating large quantities of neutralizing anti-serum that could be used in a viral outbreak scenario.

MONKEY BITES AND INJURIES IN THE ZAGREB ANTIRABIES CLINIC IN 2014

SUMMARY – Travelling around the world and visiting distant places and countries (especially national parks, parks of nature, natural resorts, etc.) sometimes may result in animal bites and injuries from the species which are not usually represented as the source of human rabies cases, such as monkeys. In the last ten to fifteen years, monkey bites and injuries present an unpleasant experience and cause a lot of problems for travelers and tourists when travelling to India, Thailand, Indonesia or Bali because they have to seek a medical facility for wound treatment, tetanus prophylaxis, antimicrobial therapy and rabies postexposure prophylaxis (PEP). In 2014, 706 persons were registered at the Zagreb Antirabies Clinic as having sustained bites by various animals, ten of them reported to have been bitten or injured by monkeys. Nine of them sustained injuries during their travel to India, Thailand, Indonesia and Bali. All injuries occurred when they wanted to pet or tried to feed monkeys, or refused to give them food. Most of the monkeys were macaques, capuchins, or of unknown type. Only one monkey bite recorded in the city of Zagreb occurred in the Zagreb ZOO while a professional animal handler was feeding a capuchin monkey in the cage. He did not receive rabies PEP, but instead, the capuchin monkey was put under veterinary supervision. All other patients started with PEP in the countries where the injuries occurred and continued/completed it at the Zagreb Antirabies Clinic. They received antirabies vaccine only (PVRV, RABIPUR) upon 5-dose regimen (Essen scheme) and 2-1-1 (Zagreb scheme) regimen. None of them contracted rabies. After many years, monkeys were the animal species immediately following dogs and cats in the official report of the Zagreb Antirabies Clinic, which was quite surprising. Usually, monkey bites and injuries do not present a serious problem in daily routine because they occur sporadically.

Selected Zoonoses

Human risks of acquiring a zoonotic disease from animals used in biomedical research have declined over the last decade because higher quality research animals have defined microbiologic profiles. Even with diminished risks, the potential for exposure to infectious agents still exists, especially from larger species such as nonhuman primates, which may be obtained from the wild, and from livestock, dogs, ferrets, and cats, which are generally not raised in barrier facilities and are not subject to the intensive health monitoring performed routinely on laboratory rodents and rabbits. Additionally, when laboratory animals are used as models for infectious disease studies, exposure to microbial pathogens presents a threat to human health. Also, with the recognition of emerging diseases, some of which are zoonotic, constant vigilance and surveillance of laboratory animals for zoonotic diseases are still required.

Monkey bites among US military members, Afghanistan, 2011

Bites from Macaca mulatta monkeys, native to Afghanistan, can cause serious infections. To determine risk for US military members in Afghanistan, we reviewed records for September-December 2011. Among 126 animal bites and exposures, 10 were monkey bites. Command emphasis is vital for preventing monkey bites; provider training and bite reporting promote postexposure treatment.