Ability of vaccine strain induced antibodies to neutralize field isolates of caliciviruses from Swedish cats

Abstract

BackgroundFeline calicivirus (FCV) is a common cause of upper respiratory tract disease in cats worldwide. Its characteristically high mutation rate leads to escape from the humoral immune response induced by natural infection and/or vaccination and consequently vaccines are not always effective against field isolates. Thus, there is a need to continuously investigate the ability of FCV vaccine strain-induced antibodies to neutralize field isolates.MethodsSeventy-eight field isolates of FCV isolated during the years 2008–2012 from Swedish cats displaying clinical signs of upper respiratory tract disease were examined in this study. The field isolates were tested for cross-neutralization using a panel of eight anti-sera raised in four pairs of cats following infection with four vaccine strains (F9, 255, G1 and 431).ResultsThe anti-sera raised against F9 and 255 neutralised 20.5 and 11.5 %, and 47.4 and 64.1 % of field isolates tested, respectively. The anti-sera against the more recently introduced vaccine strains G1 and 431 neutralized 33.3 and 70.5 % and 69.2 and 89.7 %, respectively. Dual vaccine strains displayed a higher cross-neutralization.ConclusionsThis study confirms previous observations that more recently introduced vaccine strains induce antibodies with a higher neutralizing capacity compared to vaccine strains that have been used extensively over a long period of time. This study also suggests that dual FCV vaccine strains might neutralize more field isolates compared to single vaccine strains. Vaccine strains should ideally be selected based on updated knowledge on the antigenic properties of field isolates in the local setting, and there is thus a need for continuously studying the evolution of FCV together with the neutralizing capacity of vaccine strain induced antibodies against field isolates at a national and/or regional level.Electronic supplementary materialThe online version of this article (doi:10.1186/s13028-015-0178-z) contains supplementary material, which is available to authorized users.

Comparative efficacy of the Leucofeligen™ FeLV/RCP and Purevax™ RCP FeLV vaccines against infection with circulating feline Calicivirus

“…This observation is in agreement with previous studies showing that the absence of seroneutralising FCV antibodies is not correlated with an absence of protection [ 13 , 15 ] and in terms of antibody protection, the levels of IgA mucosal antibodies, if available, would be a more appropriate marker of the efficacy of the mucosal defense and ultimate shedding [ 13 ]. Indeed, despite a certain level of cross-neutralisation, NAbs are quite specific of the strain used to induce them [ 13 , 16 , 17 ]. The protection against heterologous strains is also and sometimes mainly induced by the cell-mediated immune response triggered by the vaccine and the IgGs, not necessarily neutralising, directed against various viral or infected-cell antigens (total IgGs) [ 5 – 7 , 18 ].…”

Immune Response Modulation by Caliciviruses

“…Specific antibodies have been detected in several animals and humans after being exposed to caliciviruses. Induction of a humoral response has been documented with an attenuated strain of FCV in housecats (86), and with a wild type strain of RHDV in young rabbits (87), although different levels of protection against reinfection are achieved; moreover, it is also known that humoral response is required to completely clear MNV infection (88). A high prevalence of serum antibodies to HuNoV has been widely documented in children and adults; however, the protective role in the infection clearance is still a subject of discussion (89).…”

Isolation and Phylogenetic Analysis of Feline Calicivirus in Siberia

“…По данным некоторых исследователей, вакцины, изготовленные на основе референсных штаммов F9 и F255, не всегда защищают животных от калицивирусной инфекции, что вызвано генетической вариабельностью вируса и различиями между полевыми и вакцинными штаммами в пределах 21,3-38% [4,8,19,26]. Мутации в геноме вируса затрагивают области, ответственные за репродукцию капсидных белков.…”

“…Полученные данные свидетельствуют о наличии генетических различий между полевыми сибирскими изолятами и вакцинными штаммами, к тому же практический опыт использования вакцин на их основе, рост заболеваемости кошек в регионе указывают на их недостаточную эффективность. В данной работе для секвенирования мы использовали регион второй открытой рамки считывания (ORF2), анализ последовательностей которого, возможно, не полностью отражает уровень мутации генома вируса, поэтому для более глубокого анализа этих различий необходимо проводить сравнительное изучение нуклеотидных последовательностей полного генома вируса [26].…”