Whole-Inactivated and Virus-Like Particle Vaccine Strategies for Chikungunya Virus

Abstract

Chikungunya virus (CHIKV) is a mosquito-borne alphavirus in the family Togaviridae that causes a febrile, systemic illness associated with disabling polyarthralgias [1]. CHIKV is a global public health threat for which a preventive vaccine is needed. Initial attempts at vaccine development for CHIKV began in the early 1960s, after the virus was isolated from a member of the Makonde tribe in Tanzania in 1952 [2–5] and identified by the East African Virology Research Institute (now the Ugandan Virology Research Institute). CHIKV has reemerged sporadically roughly every 2 to 50 years [6, 7]. Notably, a 2005 outbreak that started in Kenya and spread across the Indian Ocean mainly by viremic travelers was found to have been propelled by a specific mutation in the E1 protein that increased the viral infectivity of the Aedes albopictus vector, enabling broader dissemination of CHIKV [8]. Vaccine development efforts in turn were reignited; CHIKV vaccine candidates using diverse platforms emerged, including live-attenuated vaccines, which were immunogenic but accompanied by arthralgia in clinical trials [9, 10]; recombinant modified vaccinia Ankara, measles, and adenovirus-vectored vaccines [11–14]; a chimeric alphavirus vaccine [15, 16]; and DNA vaccine candidates [11, 17–19]. Herein, we focus discussion on 2 additional platforms for CHIKV vaccine development: whole-inactivated and virus-like particle (VLP) approaches.

Go to:

WHOLE-INACTIVATED VACCINES

Whole-inactivated vaccines may provide an enhanced safety profile over traditional live vaccines as the inactivated viral pathogen is inactivated and thus nonreplicating and cannot revert to its virulent form [20, 21]. Whole-inactivated antiviral vaccines are currently licensed for polio, hepatitis A, Japanese encephalitis, influenza, and rabies, and a Vero cell culture–derived whole-virus inactivated Ross river virus vaccine has successfully advanced to phase 3 clinical trial evaluation [22]. Virus inactivation is achieved through chemical or physical methods; however, the inactivation process has the potential to alter viral epitopes and adversely affect immunogenicity because the native structure of the viral antigen is not always maintained. In turn, administration of multiple doses, booster injections, or the addition of adjuvant is often required to achieve protective humoral immune responses [20].

Beginning in the early 1960s, inactivation of CHIKV has been achieved through formalin, β-propiolactone, 1,5 iodonapthyl azide, binary ethyleneimine, or UV irradiation, enabling evaluation of whole-inactivated CHIKV vaccine candidates in preclinical trials [4, 23–26]. A formalin-inactivated CHIKV vaccine prepared in African green monkey tissue culture was previously evaluated in 16 healthy adults and shown to be well tolerated and immunogenic [4]. More recently, a Vero cell–cultured, formalin-inactivated Alhydrogel-adjuvanted CHIKV candidate vaccine based on the East-Central-South African CHIKV strain isolated during the 2006 epidemic in India was shown to elicit high-titer enzyme-linked immunosorbent assay (ELISA) and neutralizing antibodies in mice [27].

Go to:

VLP VACCINES

VLP vaccines consist of self-assembled viral structural proteins that mimic the conformation of wild-type virus [28]. By displaying antigenic epitopes that resemble wild-type virus in a high-density display, VLP vaccines are immunogenic and induce highly neutralizing antibody titers [29]. VLPs provide an enhanced safety profile as they are nonreplicating, noninfectious constructs. Because live virus is not used in manufacturing, neither viral attenuation nor viral inactivation is needed during vaccine production, and this also enables low-containment manufacturing. VLP vaccines have been used against hepatitis B virus and human papillomavirus, and at least 2 VLP candidate vaccines are being evaluated for CHIKV [30–32].

One mammalian cell–produced CHIKV VLP candidate vaccine is in advanced clinical development following encouraging preclinical and early phase clinical evaluation. Expression vectors encoding the CHIKV structural proteins (C-E3-E2-6K-E1) from the West African CHIKV strain 37 997 transfected into 293 T HEK cells result in the production of VLPs that resemble wild-type virus with E1 and E2 glycoproteins organized into heterodimers [31]. In preclinical testing in nonhuman primates, this VLP vaccine generated neutralizing antibody to both homologous and heterologous CHIKV strains and provided protection from viremia in a live CHIKV challenge model; the mechanistic correlate of protection was demonstrated to be CHIKV-specific neutralizing antibody [31].

In 2011, this CHIKV VLP nonadjuvanted vaccine candidate was evaluated in phase 1 testing in 25 healthy adults ages 18–50 years. The vaccine was well tolerated and without dose-limiting toxicity. Subjects received a 3-dose regimen of either 10, 20 or 40 mcg at weeks 0, 4 and 20 by intramuscular injection. All subjects developed robust neutralizing antibody titers following the first or second vaccination (geometric mean titers of the half maximum inhibitory concentration, 2688 in the 10-μg group, 1775 in the 20-μg group, and 7246 in the 40-μg group), as well as durable humoral responses that persisted at least 6 months following completion of the regimen [33]. Neutralizing antibody titers, assessed by a previously described reproducible, quantitative assay [34], reached levels inferred to be protective following natural infection [35, 36], by comparison to human convalescent neutralizing antibody responses in the same assay. Based on this phase 1 safety and immunogenicity data, the 20-μg dose on a 0- and 1-month schedule was advanced into phase 2 evaluation in a randomized, placebo-controlled trial in CHIKV-endemic regions of the Caribbean (Clinicaltrials.gov NCT02562482).

Go to:

EFFICACY EVALUATIONS

A promising vaccine could be used in outbreak settings where attack rates are high in relatively naive populations. Approaches to evaluate efficacy of a vaccine against an emerging viral disease that may be sporadic in nature may include a traditional randomized controlled trial or the “ring” vaccination approach, which was recently successfully used in the West African Ebola epidemic [37]. Complications related to efficacy evaluation in the context of sporadic outbreak include issues related to subclinical infections masking cases of disease [38] and difficulties in defining the primary source of exposure in the case of mosquito and human vector.

Efficacy data will contribute to the demonstration and validation of a correlate of immunity. The CHIKV envelope antigens are highly immunogenic in several platforms; there is good evidence that neutralizing antibody activity is a correlate of immunity. Therefore, it appears that vaccine development is biologically feasible. If this can be proven in human field trials, it may be feasible to license vaccines on the basis of their safety and immunogenicity.

Go to:

SUMMARY

CHIKV represents a rapidly emerging global infection in which the debilitating arthritis and high attack rates create a public health imperative to develop a safe and effective vaccine. In addition to people living in CHIKV-endemic regions, target populations include travelers and guest workers, such as military personnel, in such regions. Just as the epidemic has spread in Asia because of the extended range of the A. albopictus mosquito, it is likely that similar adaptations will eventually occur in the Americas to extend the scope of that epidemic, so the relevant populations for vaccination may also expand.

Ultimately, a successful vaccine will need to be well tolerated, safe, devoid of significant vaccine-associated adverse events such as arthralgia or arthritis, and induce high levels of durable efficacy in the general population. In addition, it will need to have manufacturing, stability, and delivery characteristics that make it cost-effective. Whole-inactivated vaccine approaches may have relatively low manufacturing costs, but the virus would have to be grown under high-level containment, and steps would need to be taken to ensure that antigenicity is not altered by the inactivation process. VLP vaccines have the advantage of maintaining authentic structures and antigenicity and are very safe. If they can be produced efficiently and achieve sufficient stability, they would serve as ideal immunogens. Both the whole-inactivated and VLP-based approaches can induce high levels of antibody, but they may require more than a single dose for optimal immunogenicity. Conversely, replication-competent chimeric or vectored approaches may induce a lower level of antibody but may achieve maximal immunogenicity after a single dose, and therefore, if effective, could also be suited for outbreak intervention, using a ring vaccination approach. Accordingly, it will be important to advance >1 vaccine technology platform into field testing to provide the data needed to determine approaches that best fit the public health needs of a particular region or population.

Go to:

Notes

Financial support. This work was supported by the Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health.

Potential conflicts of interest. All authors: No reported conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.

Go to:

References

1. Weaver SC, Lecuit M. Chikungunya virus and the global spread of a mosquito-borne disease. N Engl J Med 2015; 372:1231–9. [PubMed] [Google Scholar]
2. Eckels KH, Harrison VR, Hetrick FM. Chikungunya virus vaccine prepared by Tween-ether extraction. Appl Microbiol 1970; 19:321–5. [PMC free article] [PubMed] [Google Scholar]
3. Harrison VR, Binn LN, Randall R. Comparative immunogenicities of chikungunya vaccines prepared in avian and mammalian tissues. Am J Trop Med Hyg 1967; 16:786–91. [PubMed] [Google Scholar]
4. Harrison VR, Eckels KH, Bartelloni PJ, Hampton C. Production and evaluation of a formalin-killed chikungunya vaccine. J Immunol 1971; 107:643–7. [PubMed] [Google Scholar]
5. White A, Berman S, Lowenthal JP. Comparative immunogenicities of chikungunya vaccines propagated in monkey kidney monolayers and chick embryo suspension cultures. Appl Microbiol 1972; 23:951–2. [PMC free article] [PubMed] [Google Scholar]
6. Morrison TE. Reemergence of chikungunya virus. J Virol 2014; 88:11644–7. [PMC free article] [PubMed] [Google Scholar]
7. Powers AM, Logue CH. Changing patterns of chikungunya virus: re-emergence of a zoonotic arbovirus. J Gen Virol 2007; 88:2363–77. [PubMed] [Google Scholar]
8. Tsetsarkin KA, Vanlandingham DL, McGee CE, Higgs S. A single mutation in chikungunya virus affects vector specificity and epidemic potential. PLoS Pathog 2007; 3:e201. [PMC free article] [PubMed] [Google Scholar]
9. Edelman R, Tacket CO, Wasserman SS, Bodison SA, Perry JG, Mangiafico JA. Phase II safety and immunogenicity study of live chikungunya virus vaccine TSI-GSD-218. Am J Trop Med Hyg 2000; 62:681–5. [PubMed] [Google Scholar]
10. Plante K, Wang E, Partidos CD et al. . Novel chikungunya vaccine candidate with an IRES-based attenuation and host range alteration mechanism. PLoS Pathog 2011; 7:e1002142. [PMC free article] [PubMed] [Google Scholar]
11. Garcia-Arriaza J, Cepeda V, Hallengard D et al. . A novel poxvirus-based vaccine, MVA-CHIKV, is highly immunogenic and protects mice against chikungunya infection. J Virol 2014; 88:3527–47. [PMC free article] [PubMed] [Google Scholar]
12. Brandler S, Ruffie C, Combredet C et al. . A recombinant measles vaccine expressing chikungunya virus-like particles is strongly immunogenic and protects mice from lethal challenge with chikungunya virus. Vaccine 2013; 31:3718–25. [PubMed] [Google Scholar]
13. Wang D, Suhrbier A, Penn-Nicholson A et al. . A complex adenovirus vaccine against chikungunya virus provides complete protection against viraemia and arthritis. Vaccine 2011; 29:2803–9. [PMC free article] [PubMed] [Google Scholar]
14. Ramsauer K, Schwameis M, Firbas C et al. . Immunogenicity, safety, and tolerability of a recombinant measles-virus-based chikungunya vaccine: a randomised, double-blind, placebo-controlled, active-comparator, first-in-man trial. Lancet Infect Dis 2015; 15:519–27. [PubMed] [Google Scholar]
15. Wang E, Volkova E, Adams AP et al. . Chimeric alphavirus vaccine candidates for chikungunya. Vaccine 2008; 26:5030–9. [PMC free article] [PubMed] [Google Scholar]
16. Roy CJ, Adams AP, Wang E et al. . Chikungunya vaccine candidate is highly attenuated and protects nonhuman primates against telemetrically monitored disease following a single dose. J Infect Dis 2014; 209:1891–9. [PMC free article] [PubMed] [Google Scholar]
17. Muthumani K, Lankaraman KM, Laddy DJ et al. . Immunogenicity of novel consensus-based DNA vaccines against chikungunya virus. Vaccine 2008; 26:5128–34. [PMC free article] [PubMed] [Google Scholar]
18. Hallengard D, Lum FM, Kummerer BM et al. . Prime-boost immunization strategies against chikungunya virus. J Virol 2014; 88:13333–43. [PMC free article] [PubMed] [Google Scholar]
19. Mallilankaraman K, Shedlock DJ, Bao H et al. . A DNA vaccine against chikungunya virus is protective in mice and induces neutralizing antibodies in mice and nonhuman primates. PLoS Negl Trop Dis 2011; 5:e928. [PMC free article] [PubMed] [Google Scholar]
20. Zepp F. Principles of vaccine design-lessons from nature. Vaccine 2010; 28(suppl 3):C14–24. [PubMed] [Google Scholar]
21. Sanders B, Koldijk M, Schuitemaker H. Vaccine analysis: strategies, principles, and control. Berlin, Heidelberg: Springer-Verlag, 2015; 45–80. [Google Scholar]
22. Wressnigg N, van der Velden MV, Portsmouth D et al. . An inactivated Ross River virus vaccine is well tolerated and immunogenic in an adult population in a randomized phase 3 trial. Clin Vaccine Immunol 2015; 22:267–73. [PMC free article] [PubMed] [Google Scholar]
23. Kumar M, Sudeep AB, Arankalle VA. Evaluation of recombinant E2 protein-based and whole-virus inactivated candidate vaccines against chikungunya virus. Vaccine 2012; 30:6142–9. [PubMed] [Google Scholar]
24. Sharma A, Gupta P, Maheshwari RK. Inactivation of chikungunya virus by 1,5 iodonapthyl azide. Virol J 2012; 9:301. [PMC free article] [PubMed] [Google Scholar]
25. Gardner J, Anraku I, Le TT et al. . Chikungunya virus arthritis in adult wild-type mice. J Virol 2010; 84:8021–32. [PMC free article] [PubMed] [Google Scholar]
26. Nakao E, Hotta S. Immunogenicity of purified, inactivated chikungunya virus in monkeys. Bull World Health Organ 1973; 48:559–62. [PMC free article] [PubMed] [Google Scholar]
27. Tiwari M, Parida M, Santhosh SR, Khan M, Dash PK, Rao PV. Assessment of immunogenic potential of Vero adapted formalin inactivated vaccine derived from novel ECSA genotype of chikungunya virus. Vaccine 2009; 27:2513–22. [PubMed] [Google Scholar]
28. Kushnir N, Streatfield SJ, Yusibov V. Virus-like particles as a highly efficient vaccine platform: diversity of targets and production systems and advances in clinical development. Vaccine 2012; 31:58–83. [PMC free article] [PubMed] [Google Scholar]
29. Grgacic EV, Anderson DA. Virus-like particles: passport to immune recognition. Methods 2006; 40:60–5. [PMC free article] [PubMed] [Google Scholar]
30. Roldao A, Mellado MC, Castilho LR, Carrondo MJ, Alves PM. Virus-like particles in vaccine development. Expert Rev Vaccines 2010; 9:1149–76. [PubMed] [Google Scholar]
31. Akahata W, Yang ZY, Andersen H et al. . A virus-like particle vaccine for epidemic chikungunya virus protects nonhuman primates against infection. Nat Med 2010; 16:334–8. [PMC free article] [PubMed] [Google Scholar]
32. Metz SW, Gardner J, Geertsema C et al. . Effective chikungunya virus-like particle vaccine produced in insect cells. PLoS Negl Trop Dis 2013; 7:e2124. [PMC free article] [PubMed] [Google Scholar]
33. Chang LJ, Dowd KA, Mendoza FH et al. . Safety and tolerability of chikungunya virus-like particle vaccine in healthy adults: a phase 1 dose-escalation trial. Lancet 2014; 384:2046–52. [PubMed] [Google Scholar]
34. Pal P, Dowd KA, Brien JD et al. . Development of a highly protective combination monoclonal antibody therapy against chikungunya virus. PLoS Pathog 2013; 9:e1003312. [PMC free article] [PubMed] [Google Scholar]
35. Kam YW, Lee WW, Simarmata D et al. . Longitudinal analysis of the human antibody response to chikungunya virus infection: implications for serodiagnosis and vaccine development. J Virol 2012; 86:13005–15. [PMC free article] [PubMed] [Google Scholar]
36. Kam YW, Simarmata D, Chow A et al. . Early appearance of neutralizing immunoglobulin G3 antibodies is associated with chikungunya virus clearance and long-term clinical protection. J Infect Dis 2012; 205:1147–54. [PMC free article] [PubMed] [Google Scholar]
37. Henao-Restrepo AM, Longini IM, Egger M et al. . Efficacy and effectiveness of an rVSV-vectored vaccine expressing Ebola surface glycoprotein: interim results from the Guinea ring vaccination cluster-randomised trial. Lancet 2015; 386:857–66. [PubMed] [Google Scholar]
38. Yoon IK, Alera MT, Lago CB et al. . High rate of subclinical chikungunya virus infection and association of neutralizing antibody with protection in a prospective cohort in the Philippines. PLoS Negl Trop Dis 2015; 9:e0003764. [PMC free article] [PubMed] [Google Scholar]

Articles from The Journal of Infectious Diseases are provided here courtesy of Oxford University Press