Vaccine
-
The smallpox vaccine Vaccinia was successfully used to eradicate smallpox, but although very effective, it was a very reactogenic vaccine and responsible for the deaths of one or two people per million vaccinated. Modified Vaccinia virus Ankara (MVA) is a replication-deficient and attenuated derivative, also used in the smallpox eradication campaign and now being developed as a recombinant viral vector to produce vaccines against infectious diseases and cancer. Many clinical trials of these new vaccines have been conducted, and the findings of these trials are reviewed here. The safety of MVA is now well documented, immunogenicity is influenced by the dose and vaccination regimen, and information on the efficacy of MVA-vectored vaccines is now beginning to accumulate.
-
Modified Vaccinia virus Ankara (MVA) is a tissue culture-derived, highly attenuated strain of vaccinia virus (VACV) exhibiting characteristic defective replication in cells from mammalian hosts. In the 1960s MVA was originally generated as a candidate virus for safer vaccination against smallpox. Now, MVA is widely used in experimental vaccine development targeting important infectious diseases and cancer. ⋯ Such vaccines are attractive candidates for delivering antigens from pathogens against which no, or no effective vaccine is available, including emerging infections caused by highly pathogenic influenza viruses, chikungunya virus, West Nile virus or zoonotic orthopoxviruses. Other directions are seeking valuable vaccines against highly complex diseases such as AIDS, malaria, and tuberculosis. Here, we highlight examples of MVA candidate vaccines against infectious diseases, and review the efforts made to assess both the efficacy of vaccination and immune correlates of protection in preclinical studies.
-
Diseases such as HIV/AIDS, tuberculosis, malaria and cancer are prime targets for prophylactic or therapeutic vaccination, but have proven partially or wholly resistant to traditional approaches to vaccine design. New vaccines based on recombinant viral vectors expressing a foreign antigen are under intense development for these and other indications. ⋯ Despite the ability of recombinant MVA to induce potent humoral and cellular immune responses against transgenic antigen in humans, especially when used as the latter element of a heterologous prime-boost regimen, doubts are occasionally expressed about the ultimate feasibility of this approach. In this review, five common misconceptions over recombinant MVA are discussed, and evidence is cited to show that recombinant MVA is at least sufficiently genetically stable, manufacturable, safe, and immunogenic (even in the face of prior anti-vector immunity) to warrant reasonable hope over the feasibility of large-scale deployment, should useful levels of protection against target pathogens, or therapeutic benefit for cancer, be demonstrated in efficacy trials.
-
To determine the medical costs of laboratory-confirmed rotavirus hospitalizations and emergency department (ED) visits and estimate the economic impact of the rotavirus vaccine program. ⋯ After implementation of rotavirus immunization, the total annual medical costs decreased from $283 million to $96 million, an annual reduction of $187 million.
-
Vaccination against human papillomavirus (HPV) to prevent cervical cancer (CC) primarily targets young girls before sexual debut and is cost-effective. We assessed whether vaccination with the HPV-16/18 AS04-adjuvanted vaccine added to screening remains cost-effective in females after sexual debut compared to screening alone in Belgium. The role of protection against non-HPV-16/18 was also investigated. ⋯ Extending HPV vaccination to females post-sexual debut could lead to a substantial reduction in CC-related burden and would be cost-effective in Belgium.