Infections with feline immunodeficiency virus (FIV) are common in New Zealand, although the impact of those infections on the health status of the cats remains unclear. Although many cats are vaccinated yearly with a commercial FIV vaccine containing FIV subtypes A and D, the effectiveness of this vaccine in protection against infection with field FIVs is unclear, as a high proportion of New Zealand viruses belong to subtype C. The objective of the study was to compare the frequency of FIV infection among adult FIV-vaccinated and FIV-unvaccinated domestic cats with access to outdoors. Buccal swabs were collected by the participating veterinarians and tested for the presence of FIV provirus by quantitative PCR. Overall, 26/185 (14.0 %) samples were positive for FIV, including 7/82 (8.5 %) samples from FIV-unvaccinated and 19/103 (18.4 %) from FIV-vaccinated cats. There was no protective effect of vaccination on FIV infection among sampled cats (p = 0.05). Partial sequences of the FIV envelope gene from five New Zealand viruses were analysed by the maximum likelihood method. All clustered with other New Zealand FIV sequences from subtypes A (n = 2), C (n = 2) or putative recombinant viruses (n = 1). While the FIV vaccination did not prevent FIV infection among sampled cats, it may have had an impact on transmissibility of the virus or on disease progression. As neither was addressed in the current study, further research is needed to fully assess the potential benefits of FIV vaccination. Considering the frequency of FIV infection in FIV-vaccinated cats, FIV infection status should be monitored not only before the first vaccination, but before each yearly booster.

猫免疫缺陷病毒（FIV）感染在新西兰很常见，尽管这些感染对猫的健康状况的影响尚不清楚。尽管每年都有许多猫用含有FIV和A型FIV的商业FIV疫苗接种，但这种疫苗在预防田野FIV感染方面的有效性尚不明确，因为很大一部分新西兰病毒属于C型。这项研究的目的是比较成年FIV疫苗接种的和未接种FIV疫苗的家猫在户外接触FIV的频率。参与调查的兽医收集颊拭子，并通过定量PCR检测FIV前病毒的存在。总体而言，FIV阳性的样本为26/185（14.0％），包括未接种FIV的样本为7/82（8.5％）和19/103（18。4％）接种FIV的猫。在抽样的猫中，疫苗接种对FIV感染没有保护作用（p = 0.05）。通过最大似然法分析了来自五种新西兰病毒的FIV包膜基因的部分序列。所有这些都与来自亚型A（n = 2），C（n = 2）或推定的重组病毒（n = 1）的其他新西兰FIV序列聚集在一起。尽管FIV疫苗接种不能预防猫猫中的FIV感染，但可能对病毒的传播能力或疾病进展产生了影响。正如当前研究中未解决的那样，需要进一步研究以充分评估FIV疫苗接种的潜在益处。考虑到接种FIV的猫中FIV感染的频率，不仅应在首次接种疫苗之前，而且应在每年一次加强免疫之前监测FIV感染状况。在抽样的猫中，疫苗接种对FIV感染没有保护作用（p = 0.05）。通过最大似然法分析了来自五种新西兰病毒的FIV包膜基因的部分序列。所有这些都与来自亚型A（n = 2），C（n = 2）或推定的重组病毒（n = 1）的其他新西兰FIV序列聚集在一起。尽管FIV疫苗接种不能预防猫猫中的FIV感染，但可能对病毒的传播能力或疾病进展产生了影响。正如当前研究中未解决的那样，需要进一步研究以充分评估FIV疫苗接种的潜在益处。考虑到接种FIV的猫中FIV感染的频率，不仅应在首次接种疫苗之前，而且应在每年一次加强免疫之前监测FIV感染状况。在抽样的猫中，疫苗接种对FIV感染没有保护作用（p = 0.05）。通过最大似然法分析了来自五种新西兰病毒的FIV包膜基因的部分序列。所有这些都与来自亚型A（n = 2），C（n = 2）或推定的重组病毒（n = 1）的其他新西兰FIV序列聚集在一起。尽管FIV疫苗接种不能预防猫猫中的FIV感染，但可能对病毒的传播能力或疾病进展产生了影响。正如当前研究中未解决的那样，需要进一步研究以充分评估FIV疫苗接种的潜在益处。考虑到接种FIV的猫中FIV感染的频率，不仅应在首次接种疫苗之前，而且应在每年一次加强免疫之前监测FIV感染状况。