Limits...
The non-pathogenic Australian rabbit calicivirus RCV-A1 provides temporal and partial cross protection to lethal Rabbit Haemorrhagic Disease Virus infection which is not dependent on antibody titres.

Strive T, Elsworth P, Liu J, Wright JD, Kovaliski J, Capucci L - Vet. Res. (2013)

Bottom Line: Despite its obvious negative impacts on viral biocontrol of introduced European rabbits in Australia, little is known about the extent and mechanisms of this cross protection.Survival rates and survival times did not correlate with titres of serum antibodies specific to RCV-A1 or cross reacting to RHDV, but were instead influenced by the time between infection with the two viruses, demonstrating for the first time that the cross protection to lethal RHDV infection is transient.These findings are an important step towards a better understanding of the complex interactions of co-occurring pathogenic and non-pathogenic lagoviruses.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Ecosystem Sciences, Commonwealth Scientific and Industrial Research Organisation, Canberra ACT 2601, Australia. tanja.strive@csiro.au.

ABSTRACT
The endemic non-pathogenic Australian rabbit calicivirus RCV-A1 is known to provide some cross protection to lethal infection with the closely related Rabbit Haemorrhagic Disease Virus (RHDV). Despite its obvious negative impacts on viral biocontrol of introduced European rabbits in Australia, little is known about the extent and mechanisms of this cross protection. In this study 46 rabbits from a colony naturally infected with RCV-A1 were exposed to RHDV. Survival rates and survival times did not correlate with titres of serum antibodies specific to RCV-A1 or cross reacting to RHDV, but were instead influenced by the time between infection with the two viruses, demonstrating for the first time that the cross protection to lethal RHDV infection is transient. These findings are an important step towards a better understanding of the complex interactions of co-occurring pathogenic and non-pathogenic lagoviruses.

Show MeSH

Related in: MedlinePlus

Kaplan Meier survival analysis of rabbits challenged with RHDV. Analysis was carried out using the SigmaPlot software version 12.3. S indicates survival until 30 days post RHDV challenge when the rabbits were euthanazed.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3733936&req=5

Figure 1: Kaplan Meier survival analysis of rabbits challenged with RHDV. Analysis was carried out using the SigmaPlot software version 12.3. S indicates survival until 30 days post RHDV challenge when the rabbits were euthanazed.

Mentions: A high proportion of rabbits that had been seronegative to either RHDV or RCV-A1 when purchased and subsequently seroconverted within the following 8 weeks died in the second wave. This prompted us to investigate if the time between the infections with RCV-A1 and RHDV had an influence on survival rates and survival times, and animals were grouped according to the time between the two infections (Figure 1 and Table 1). In the group of the recently seroconverted animals (< 8 weeks between infections of RCV-A1 and RHDV) 3 of 8 rabbits survived (38%) and the animals in this group that did not survive showed prolonged survival times, with a median survival time of 9.9 days. The median survival time in the second group of animals with 8–10 weeks between infections with the two viruses was 8.0 days, and only one rabbit survived (13%). In comparison, median survival time in animals with a mature immune response in group three was 4.4 days, and in this group too only one animal survived (6%). In the Kaplan Meier survival analysis, the Logrank test was highly significant between group 1 and group 3 (p = 0.002) and significant between group 2 and group 3 (p = 0.038), but not significant between group 1 and group 2.


The non-pathogenic Australian rabbit calicivirus RCV-A1 provides temporal and partial cross protection to lethal Rabbit Haemorrhagic Disease Virus infection which is not dependent on antibody titres.

Strive T, Elsworth P, Liu J, Wright JD, Kovaliski J, Capucci L - Vet. Res. (2013)

Kaplan Meier survival analysis of rabbits challenged with RHDV. Analysis was carried out using the SigmaPlot software version 12.3. S indicates survival until 30 days post RHDV challenge when the rabbits were euthanazed.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3733936&req=5

Figure 1: Kaplan Meier survival analysis of rabbits challenged with RHDV. Analysis was carried out using the SigmaPlot software version 12.3. S indicates survival until 30 days post RHDV challenge when the rabbits were euthanazed.
Mentions: A high proportion of rabbits that had been seronegative to either RHDV or RCV-A1 when purchased and subsequently seroconverted within the following 8 weeks died in the second wave. This prompted us to investigate if the time between the infections with RCV-A1 and RHDV had an influence on survival rates and survival times, and animals were grouped according to the time between the two infections (Figure 1 and Table 1). In the group of the recently seroconverted animals (< 8 weeks between infections of RCV-A1 and RHDV) 3 of 8 rabbits survived (38%) and the animals in this group that did not survive showed prolonged survival times, with a median survival time of 9.9 days. The median survival time in the second group of animals with 8–10 weeks between infections with the two viruses was 8.0 days, and only one rabbit survived (13%). In comparison, median survival time in animals with a mature immune response in group three was 4.4 days, and in this group too only one animal survived (6%). In the Kaplan Meier survival analysis, the Logrank test was highly significant between group 1 and group 3 (p = 0.002) and significant between group 2 and group 3 (p = 0.038), but not significant between group 1 and group 2.

Bottom Line: Despite its obvious negative impacts on viral biocontrol of introduced European rabbits in Australia, little is known about the extent and mechanisms of this cross protection.Survival rates and survival times did not correlate with titres of serum antibodies specific to RCV-A1 or cross reacting to RHDV, but were instead influenced by the time between infection with the two viruses, demonstrating for the first time that the cross protection to lethal RHDV infection is transient.These findings are an important step towards a better understanding of the complex interactions of co-occurring pathogenic and non-pathogenic lagoviruses.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Ecosystem Sciences, Commonwealth Scientific and Industrial Research Organisation, Canberra ACT 2601, Australia. tanja.strive@csiro.au.

ABSTRACT
The endemic non-pathogenic Australian rabbit calicivirus RCV-A1 is known to provide some cross protection to lethal infection with the closely related Rabbit Haemorrhagic Disease Virus (RHDV). Despite its obvious negative impacts on viral biocontrol of introduced European rabbits in Australia, little is known about the extent and mechanisms of this cross protection. In this study 46 rabbits from a colony naturally infected with RCV-A1 were exposed to RHDV. Survival rates and survival times did not correlate with titres of serum antibodies specific to RCV-A1 or cross reacting to RHDV, but were instead influenced by the time between infection with the two viruses, demonstrating for the first time that the cross protection to lethal RHDV infection is transient. These findings are an important step towards a better understanding of the complex interactions of co-occurring pathogenic and non-pathogenic lagoviruses.

Show MeSH
Related in: MedlinePlus