MVA85A
Template:Short description MVA85A (modified vaccinia Ankara 85A) was a candidate vaccine against tuberculosis developed by researchers led by Professor Helen McShane at Oxford University.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> It is a viral vector vaccine and consists of an MVA virus engineered to express the 85A antigen once it infects a host cell. 85A is a cell-wall protein of the tuberculosis bacillus.
This vaccine was believed to produce higher levels of long-lasting cellular immunity when used together with the older TB vaccine BCG.<ref>Template:Cite journal</ref> Phase I clinical trials were completed in 2008 and then phase II clinical trials took place in South Africa.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>A number of efficacy trials ran in parallel from 2009 to 2019.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Results released in February 2013 were described as "disappointing", showing only a statistically insignificant prevention rate in infants.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> A summary of animal studies published in 2015 cast doubt on the efficacy of the vaccine.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}Template:Dead linkTemplate:Cbignore</ref>
In 2018, a BMJ investigation raised concerns about the ethics of an efficacy trial in South African infants, particularly because of results from earlier animal trials such as a study with macaques at Porton Down.<ref>Template:Cite journal</ref> One response argued that 14 prior human trials showed a safety signal, that regulators were aware of the primate trial and decided to continue, and that three subsequent investigations found no evidence of wrong-doing.<ref>Template:Cite journal</ref> Another response by Ian Orme questioned the critique of animal models.<ref>Template:Cite journal</ref>
A Cochrane review in 2019 concluded that MVA85A is safe, however it is not effective in preventing TB infection either on its own or in combination with BCG.<ref>Template:Cite journal</ref>