Comparative study of the immunogenicity in mice and monkeys of an inactivated CA16 vaccine made from a human diploid cell line

Keywords: bivalent and multivalent vaccines, coxsackievirus A16, coxsackieviruses B3 and B5, echovirus 30, epidemiology, enterovirus A (EV-A), enterovirus A71, hand, foot and mouth diseases, inactivated whole virion vaccines, monovalent, EV-A71 vaccine Enterovirus A infections are the primary cause of hand, foot and mouth disease (HFMD) in infants and young children. Although enterovirus 71 (EV-A71) and coxsackievirus A16 (CV-A16) are the predominant causes of HFMD epidemics worldwide, EV-A71 has emerged as a major neurovirulent virus responsible for severe neurological complications and fatal outcomes. HFMD is a serious health threat and economic burden across the Asia-Pacific region. Inactivated EV-A71 vaccines have elicited protection against EV-A71 but not against CV-A16 infections in large efficacy trials. The current development of a bivalent inactivated EV-A71/CV-A16 vaccine is the next step toward that of multivalent HFMD vaccines. These vaccines should ultimately include other prevalent pathogenic coxsackieviruses A (CV-A6 and CV-A10), coxsackieviruses B (B3 and B5) and echovirus 30 that often co-circulate during HFMD epidemics and can cause severe HFMD, aseptic meningitis and acute viral myocarditis. The prospect and challenges for the development of such multivalent vaccines are discussed.

Section: Development Of a Bivalent Ev-a71/cv-a16 Vaccinementioning

confidence: 99%

Section: Development Of a Bivalent Ev-a71/cv-a16 Vaccinementioning

confidence: 99%

Section: Cross-protective Ability Of a Multivalent Vaccine And Selectmentioning

confidence: 99%

See 1 more Smart Citation

Is a multivalent hand, foot, and mouth disease vaccine feasible?

Klein¹,

Chong

2015

“…VLPs have a greater safety profile than inactivated vaccines since they do not contain the virus genome. Currently, several experimental CVA16 and EV71 vaccines are under development, including inactivated CVA16, [23][24][25] and CVA16 VLPs derived from insect cells 26 and Saccharomyces cerevisiae. 27 Among these, the EV71 inactivated vaccine has been evaluated and passed through a phase III clinical trial, while the development of EV71 VLPs in insect cells and S. cerevisiae is still ongoing.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of monovalent and bivalent vaccines against lethalEnterovirus71 andCoxsackievirusA16 infection in newborn mice

Sun

Jiang

Liang

et al. 2014

Enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16) have caused severe epidemics of hand, foot and mouth disease (HFMD) in the Asia Pacific in recent years, particularly in infants and young children. This disease has become a serious public health problem, as no vaccines or antiviral drugs have been approved for EV71 and CA16 infections. In this study, we compared four monovalent vaccines, including formalin-inactivated EV71 virus (iEV71), EV71 virus-like particles (VLPs) (vEV71), formalin-inactivated CVA16 virus (iCVA16) and CVA16 VLPs (vCVA16), along with two bivalent vaccines, including equivalent doses of formalin-inactivated EV71CCVA16 virus (iEV71CiCVA16) and EV71CCVA16 VLPs (vEV71CvCVA16). The IgG titers and neutralization antibodies titers demonstrated that there are no immune interference exists between the two immunogens of EV71 and CVA16. IgG subclass isotyping revealed that IgG1 and IgG2b were induced primarily in all vaccine groups. Furthermore, cross-neutralization antibodies were elicited in mouse sera against other sub-genotypes of EV71 and CVA16. In vivo challenge experiments showed that the immune sera from vaccinated animals could confer passive protection to newborn mice against lethal challenge with 14 LD 50 of EV71 and 50 LD 50 of CVA16. Our results indicated that bivalent vaccination is promising for HFMD vaccine development. With the advantage of having a better safety profile than inactivated virus vaccines, VLPs should be used to combine both EV71 and CVA16 antigens as a candidate vaccine for prevention of HFMD virus transmission.

“…Since then, there has been continuing interest in the development of HDCSs. Eleven, 12 However, it is extremely hard to obtain human fetal tissue from which to derive qualified human diploid cell strains. This is due to issues that include the requirement for strict ethical review, the possibility of environmental degradation, and food safety hazards, all of which may lead to chromosomal aberrations such as the presence of aneuploidy and polyploidy for the karyotype.…”

Section: Introductionmentioning

confidence: 99%

Characteristics and viral propagation properties of a new human diploid cell line, walvax-2, and its suitability as a candidate cell substrate for vaccine production

Zhang

et al. 2015

Human diploid cell strains (HDCSs), possessing identical chromosome sets known to be free of all known adventitious agents, are of great use in developing human vaccines. However it is extremely difficult to obtain qualified HDCSs that can satisfy the requirements for the mass production of vaccines. We have developed a new HDCS, Walvax-2, which we derived from the lung tissue of a 3-month-old fetus. We established primary, master and working cell banks successfully from reconstituted frozen cells. Observations during the concurrent propagation of Walvax-2 and MRC-5 cells revealed differences in terms of growth rate, cell viability and viral sensitivities. Specifically, Walvax-2 cells replicated more rapidly than MRC-5 cells, with Walvax-2 cells attaining the same degree of confluence in 48 hours as was reached by MRC-5 cells in 72 hours. Moreover, Walvax-2 cells attained 58 passages of cell doublings whereas MRC-5 reached 48 passages during this period. We also assessed the susceptibility of these cells to rabies, hepatitis A, and Varicella viruses. Analysis of virus titers showed the Walvax-2 cells to be equal or superior to MRC-5 cells for cultivating these viruses. Furthermore, in order to characterize the Walvax-2 cell banks, a series of tests including cell identification, chromosomal characterization, tumorigenicity, as well as tests for the presence of microbial agents, exogenous viruses, and retroviruses, were conducted according to standard international protocols. In conclusion, results from this study show that Walvax-2 cell banks are a promising cell substrate and could potentially be used for the manufacturing of HDCVs.