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The Smallpox Story
Published in Rae-Ellen W. Kavey, Allison B. Kavey, Viral Pandemics, 2020
Rae-Ellen W. Kavey, Allison B. Kavey
Originally, the pox material used for vaccination was kept alive by being transferred from arm to arm, including serial infection of children as a way to transport the virus across the ocean from Europe to the Spanish colonies in the Americas early in the nineteenth century.30 Contamination as a result of this arm-to-arm procedure led to inadvertent transmission of other serious diseases, including syphilis and tuberculosis, so the vaccine was subsequently produced on the skin of animals, primarily calves but also rabbits and horses.31 Somewhere in this process, the original cowpox vaccine agent was replaced by a brand new, previously unknown virus, which was called “vaccinia.” Vaccinia was subsequently found to be an immunologically distinct strain, thought to possibly be derived from the cowpox virus by repeated serial passage in animals.30 Alternatively, Vaccinia, cowpox virus, and Variola are thought to all be derivatives of a common ancestral virus with cross-immunity insuring that infection with one provides protection against all. Whatever the origin, Vaccinia became the consistent agent used in vaccines against smallpox from the early 1900s.31,32
ExperimentaL Oral Medicine
Published in Samuel Dreizen, Barnet M. Levy, Handbook of Experimental Stomatology, 2020
Samuel Dreizen, Barnet M. Levy
Kreshover et al.48 determined the effects of vaccinia infection in pregnant rabbits on maternal and fetal dental tissues. Vaccinia virus in 1 mℓ doses of titers ranging from 10−4 to 10−6 were injected into the ear veins of 46 female California and New Zealand albino rabbits ranging in age from 6 to 11 months. Of the 33 virgins, 14 were injected 6 to 16 days prior to mating; the remainder, after mating. Of the group, 12 were inoculated during the first trimester of pregnancy (1 to 10 days), 4 during the second trimester (11 to 20 days), and 3 during the third trimester (21 to 30 days). Two rabbits in each group were permitted to complete pregnancy without disturbance. Caesarean sections were performed in the others at different stages of gestation. Young, spontaneously delivered at term were killed at intervals between 1 and 60 days of age. Their mandibles and maxillas, along with those of the fetuses removed by section, were prepared for histologic study. Blood and tissues were tested for the presence of vaccinia virus.
Chemical and Biological Threats to Public Safety
Published in Frank A. Barile, Barile’s Clinical Toxicology, 2019
Although routine vaccination against smallpox ended in 1972, the level of continuous immunity among persons vaccinated before 1972 is uncertain. Recently, the threat that smallpox could be used as a weapon of bioterrorism has prompted the development of new vaccination strategies for both military personnel and civilians. Vaccinia, a form of cowpox, is used for the production of smallpox vaccine. The procedure consists of scratching live virus into the patient’s skin and observing for the formation of vesicle and pustules. In October 2002, the FDA approved a new 100-dose kit for smallpox vaccine (Dryvax®, Wyeth), the only currently licensed smallpox vaccine. All supplies of Dryvax® for civilian use are under CDC control. Complications and potential risks related to vaccination occur primarily in immunocompromised individuals and, more recently, in persons with preexisting cardiovascular disorders. The most serious complications are encephalitis, progressive infection (vaccinia necrosum), and myocardial infarction.
Reemergence of monkeypox: prevention and management
Published in Expert Review of Anti-infective Therapy, 2022
Sahaya Nadar, Tabassum Khan, Abdelwahab Omri
The CDC Drug Services provides the following vaccine recommendations for individuals placed in the high risk category by virtue of occupational exposure to this virus. A live, non-replicating vaccine, JYNNEOS is approved by the US FDA for the prevention of smallpox and monkeypox in adults (18 years and older) who were assessed to have a high risk of infection. The JYNNEOS vaccine is different from ACAM2000 and APSV as it is an attenuated live virus. Being in a replication-deficient form, it can be used toward certain immune deficiencies like AIDS or atopic dermatitis [75,76].The ACAM2000 is a live vaccine for active immunization against smallpox disease licensed by the US FDA for people who are at high risk of contracting smallpox. It is free from the variola virus, so they cannot cause smallpox but has the vaccinia virus belonging to the poxvirus family. There may be incidences of head and body aches, rash and fever owing to the presence of the vaccinia virus. Some groups of people, specifically those who are immunocompromised, are susceptible to severe complications caused by vaccinia [77,78].Aventis Pasteur Smallpox Vaccine (APSV)
Developing effective vaccines: Cues from natural infection
Published in International Reviews of Immunology, 2018
Vishakha Bhurani, Aditi Mohankrishnan, Alexandre Morrot, Sarat Kumar Dalai
Live attenuated and inactivated vaccines induce both cellular and humoural immunity, and the early vaccines were examples of T cell-mediated vaccines. The mechanism of protection induced by vaccinia was also unknown at the time of smallpox eradication, but recent studies indicate that B cells are required for protection against smallpox, whereas T cells are required to control the spread of the vaccinia virus itself following vaccination.30 Moreover, for vaccine against tuberculosis first used in the 1920s and still in use today, a T-cell response is essential for protection. BCG is a live attenuated strain of M. bovis, the causative agent of bovine tuberculosis and an intracellular bacterium. Both CD4+ and CD8+ T cells are involved in protection against disease. BCG may be considered the first T-cell-inducing vaccine, and is still the only licensed vaccine thought to work primarily through T-cell responses, but is not a good model to follow for future vaccine strategies because its efficacy is highly variable.11,23
Poxvirus-based vector systems and the potential for multi-valent and multi-pathogen vaccines
Published in Expert Review of Vaccines, 2018
Natalie A. Prow, Rocio Jimenez Martinez, John D. Hayball, Paul M. Howley, Andreas Suhrbier
Avoiding needles has a series of inherent advantages [99,100] and a number of needle-free vaccination strategies are being developed (Table 5). Smallpox vaccines were usually given using a process of scarification, which involves using a bifurcated needle (which holds a droplet of the vaccinia vaccine) pressed several times into the skin (deep enough to evoke a trace of blood after 15–30 s) [101]. A multi-dose jet injector (‘Press-o-Jet’) was also developed in 1955 for needle-free delivery of smallpox vaccines [102]. rMVA vaccines are usually given via a needle using the intramuscular route (or the subcutaneous route), although the percutaneous route has also worked in preclinical studies [103]. Vet Jet™ delivery of Purevax® represents the first licensed needle-free delivery of a recombinant poxvirus vaccine, with Stratis jet injection of MVA in phase 2 human clinical trials. Other technologies include needle-free intradermal delivery of solid dissolvable vaccine formulations (ImplaVax™) (Table 5). Clearly of considerable value would be systems that provide both lyophilization, solidification, or dry coating technologies that reduce cold chain requirements combined with needle-free delivery. Progress in this field may also open new avenues for multi-vaccine co-delivery, with ‘dry vaccines’ potentially overcoming some of the hurdles associated with simple mixing of multiple liquid vaccines.