scholarly journals Comparison of the Whole-Genome Sequence of an Oka Varicella Vaccine from China with Other Oka Vaccine Strains Reveals Sites Putatively Critical for Vaccine Efficacy

2019 ◽  
Vol 93 (9) ◽  
Author(s):  
Qiuhua Wu ◽  
Pierre Rivailler ◽  
Songtao Xu ◽  
Wenbo Xu

ABSTRACTVaricella-zoster virus (VZV) infection results in varicella mostly in children. Reactivation of the virus causes herpes zoster (HZ), mostly in adults. A live attenuated vaccine (vOka-Biken) was originally derived from the parental strain pOka. Several live attenuated vaccines based on the Oka strain are currently available worldwide. In China, varicella vaccines have been licensed by four manufacturers. In this study, we analyze the whole-genome sequence (WGS) of vOka-BK produced by Changchun BCHT Biotechnology also known as Baike. vOka-BK WGS was compared against the genomic sequences of four other Oka strains: pOka, vOka-Biken, vOka-Varilrix from GlaxoSmithKline, and vOka-Varivax from Merck & Co. A previous study identified 137 single nucleotide polymorphisms (SNPs) shared by all vOkas. The current analysis used these data as a reference to compare with vOka-BK WGS and focused on 54 SNPs located in the unique regions of the genome. Twenty-eight nonsynonymous substitutions were identified, ORF62 and ORF55 featuring the most amino acid changes with 9 and 3, respectively. Among the 54 SNPs, 10 had a different mutation profile in vOka-BK compared to the other three vaccines. A comparison with the clade 3 strain Ellen, known to be attenuated, identified three shared amino acid changes: *130R in ORF0 and R958G and S628G in ORF62. This analysis provides the first comparison of a Chinese varicella vaccine to the other vaccines available worldwide and identifies sites potentially critical for VZV vaccine efficacy.IMPORTANCEVaricella, also known as chickenpox, is a highly contagious disease, caused by varicella-zoster virus (VZV). Varicella is a common childhood disease that can be prevented by a live attenuated vaccine. The first available vaccine was derived from the parental Oka strain in Japan in 1974. Several live attenuated vaccines based on the Oka strain are currently available worldwide. Among the four vaccines produced in China, the vaccine manufactured by Changchun BCHT Biotechnology, also known as Baike, has been reported to be very efficacious. Comparative genomic analysis of the Baike vaccine with other Oka vaccine strains identified sites that might be involved in vaccine efficacy, as well as important for the biology of the virus.

2021 ◽  
Author(s):  
Anne Gershon

A live attenuated vaccine against varicella (later also used to prevent zoster) was developed in 1974 by Takahashi and colleagues. Varicella vaccine was licensed for universal immunization of healthy children in the United States in 1995. It is also now used for this purpose in at least 15 additional countries all over the world. Varicella is disappearing in the US. Varicella vaccine has proven extremely safe and side effects are unusual, mild, and less serious than varicella or its complications. 85% of children are protected completely after 1 dose; the 15% who develop varicella despite immunization usually (but not always) have mild infections. These 15%, however, can transmit the wild type virus to others. Therefore, for optimal effect, 2 doses are required, mostly to address children who did not have an optimal primary immune response after the first dose. Waning immunity does not seem to pose a serious problem, but surveillance of vaccinees is continuing. It was demonstrated in 2005 that at a high dose of vaccine – 15 times higher than that used for prevention of varicella in children - zoster in adults can also be safely prevented. The live attenuated zoster vaccine is effective in approximately 50% of healthy individuals over age 60 who have had varicella in the past, and therefore have latent infection with varicella-zoster virus. It is given as one dose, but its effect runs out about 8 years after vaccination. In 2017, a new vaccine against zoster was also introduced. This is a subunit vaccine which does not contain contagious virus. It is even more effective than the older zoster vaccine and is over 95% effective in adults 50–≥70 years of age in preventing zoster and post herpetic neuralgia.


2017 ◽  
Vol 5 (28) ◽  
Author(s):  
Sara Jones ◽  
Raji Prasad ◽  
Anjana S. Nair ◽  
Sanjai Dharmaseelan ◽  
Remya Usha ◽  
...  

ABSTRACT We report here the whole-genome sequence of six clinical isolates of influenza A(H1N1)pdm09, isolated from Kerala, India. Amino acid analysis of all gene segments from the A(H1N1)pdm09 isolates obtained in 2014 and 2015 identified several new mutations compared to the 2009 A(H1N1) pandemic strain.


2002 ◽  
Vol 76 (2) ◽  
pp. 591-599 ◽  
Author(s):  
Thomas C. Heineman ◽  
Susan L. Hall

ABSTRACT To study the function of the varicella-zoster virus (VZV) gB cytoplasmic domain during viral infection, we produced a VZV recombinant virus that expresses a truncated form of gB lacking the C-terminal 36 amino acids of its cytoplasmic domain (VZV gB-36). VZV gB-36 replicates in noncomplementing cells and grows at a rate similar to that of native VZV. However, cells infected with VZVgB-36 form extensive syncytia compared to the relatively small syncytia formed during native VZV infection. In addition, electron microscopy shows that very little virus is present on the surfaces of cells infected with VZV gB-36, while cells infected with native VZV exhibit abundant virions on the cell surface. The C-terminal 36 amino acids of the gB cytoplasmic domain have been shown in transfection-based experiments to contain both an endoplasmic reticulum-to-Golgi transport signal (the C-terminal 17 amino acids) and a consensus YXXφ (where Y is tyrosine, X is any amino acid, and φ is any bulky hydrophobic amino acid) signal sequence (YSRV) that mediates the internalization of gB from the plasma membrane. As predicted based on these data, gB-36 expressed during the infection of cultured cells is transported inefficiently to the Golgi. Despite lacking the YSRV signal sequence, gB-36 is internalized from the plasma membrane; however, in contrast to native gB, it fails to localize to the Golgi. Therefore, the C-terminal 36 amino acids of the VZV gB cytoplasmic domain are required for normal viral egress and for both the pre- and post-Golgi transport of gB.


2021 ◽  
Author(s):  
Labchan Rajbhandari ◽  
Priya Shukla ◽  
Balaji Jagdish ◽  
Abby Mandalla ◽  
Qingxue Li ◽  
...  

Varicella zoster virus (VZV) maintains lifelong latency in neurons following initial infection and can subsequently be reactivated to result in herpes zoster or severe neurological manifestations such as encephalitis. Mechanisms of VZV neuropathogenesis have been challenging to study due to the strict human tropism of the virus. While neuronal entry mediators of other herpesviruses, including herpes simplex virus, have been identified, little is known regarding how VZV enters neurons. Here, we utilize a human stem cell based neuronal model to characterize cellular factors that mediate entry. Through transcriptional profiling of infected cells, we identify the cell adhesion molecule nectin-1 as a candidate mediator of VZV entry. Nectin-1 is highly expressed in the cell bodies and axons of neurons. Either knockdown of endogenous nectin-1 or incubation with soluble forms of nectin-1 produced in mammalian cells results in a marked decrease in infectivity of neurons. Notably, while addition of soluble nectin-1 during viral infection inhibits infectivity, addition after infection has no effect on infectivity. Ectopic expression of human nectin-1 in a cell line resistant to productive VZV infection confers susceptibility to infection. In summary, we have identified nectin-1 as a neuronal entry mediator of VZV. IMPORTANCE Varicella zoster virus (VZV) causes chickenpox, gains access to neurons during primary infection where it resides lifelong, and can later be reactivated. Reactivation is associated with shingles and postherpetic neuralgia, as well as with severe neurologic complications including vasculitis and encephalitis. Although the varicella vaccine substantially decreases morbidity and mortality associated with primary infection, the vaccine cannot prevent development of neuronal latency and vaccinated populations are still at risk for reactivation. Furthermore, immunocompromised individuals are at higher risk for VZV reactivation and associated complications. Little is known regarding how VZV enters neurons. Here, we identify nectin-1 as an entry mediator of VZV in human neurons. Identification of nectin-1 as a neuronal VZV entry mediator could lead to improved treatments and preventative measures to reduce VZV related morbidity and mortality.


PEDIATRICS ◽  
1985 ◽  
Vol 75 (4) ◽  
pp. 667-671 ◽  
Author(s):  
Yoshizo Asano ◽  
Takao Nagai ◽  
Takao Miyata ◽  
Takehiko Yazaki ◽  
Shigemitsu Ito ◽  
...  

In spite of close contacts with patients who had varicella, 101 of 106 (95%) healthy and sick children (142 of 147 (97%) exposures of these children) who had received the OKA strain of live varicella vaccine 7 to 10 years earlier were protected against the disease completely. Among them, 37 of 38 (97%) vaccine recipients who received immunologic testing had varicella-zoster virus (VZV) antibodies tested by fluorescent antibody to membrane antigen method with a geometric mean titer of 1:9.3, and 37 of the 38 (97%) showed positive skin reaction to varicella-zoster virus antigen with erythema (mean diameter 13.4 mm). These findings were compared with those for 29 children who had contracted typical varicella 7 to 10 years earlier, whose seropositive rate was 100% with a geometric mean titer of 1:10.5, and 97% of whom (28/29) had positive skin reaction with mean diameter of 12.9 mm. These results indicate that the vaccine-induced protective immunity persists for approximately one decade and is almost equal to the long-term immunity following natural infection.


2020 ◽  
Vol 9 (39) ◽  
Author(s):  
Maria Grazia Cusi ◽  
David Pinzauti ◽  
Claudia Gandolfo ◽  
Gabriele Anichini ◽  
Gianni Pozzi ◽  
...  

ABSTRACT The complete genome sequence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolate Siena-1/2020 was obtained by Nanopore sequencing, combining the direct RNA sequencing and amplicon sequencing approaches. The isolate belongs to the B1.1 lineage, which is prevalent in Europe, and contains a mutation in the spike protein coding sequence leading to the D614G amino acid change.


2020 ◽  
Vol 35 (13) ◽  
pp. 889-895 ◽  
Author(s):  
Veena Ramachandran ◽  
Stephen C. Elliott ◽  
Kathie L. Rogers ◽  
Randall J. Cohrs ◽  
Miles Weinberger ◽  
...  

Varicella-zoster virus vaccination is recommended for virtually all young children in the United States, Canada, and several other countries. Varicella vaccine is a live attenuated virus that retains some of its neurotropic properties. Herpes zoster caused by vaccine virus still occurs in immunized children, although the rate is much lower than in children who had wild-type varicella. It was commonly thought that 2 varicella vaccinations would protect children against the most serious complication of meningitis following herpes zoster; however, 2 meningitis cases have already been published. We now report a third case of varicella vaccine meningitis and define risk factors shared by all 3 immunized adolescents. The diagnosis in cerebrospinal fluid in this third case was verified by amplifying and sequencing portions of the viral genome, to document fixed alleles found only in the vaccine strain. Viral antibody was also detected in the cerebrospinal fluid by confocal microscopy. When compared with the other 2 cases, remarkably all 3 were 14 years old when meningitis occurred. All 3 were treated with intravenous acyclovir, with complete recovery. The adolescent in our case report also had recurrent asthma, which was treated with both prednisone tablets and beclomethasone inhaler before onset of meningitis. When the 3 cases were considered together, they suggested that immunity to varicella-zoster virus may be waning sufficiently in some twice-immunized adolescents to make them vulnerable to varicella vaccine virus reactivation and subsequent meningitis. This complication rarely happens in children after wild-type varicella.


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