Epidemiology, molecular prevalence and prevention on canine parvovirus in India: A review.

Canine parvovirus (CPV) is a highly contagious and lethal virus that causes severe gastroenteritis and myocarditis in young dogs. In 1978, CPV has rapidly spread worldwide, resulting in outbreaks and high morbidity rates among dog populations. Over a decade, CPV has undergone genetic changes, leading to the emergence of different genotypes (CPV-2a, CPV-2b, and CPV-2c), which have expanded its host range to include cats and tissue culture cells. This review focuses on CPV-2 outbreaks in India from 2010 to 2023, analyzing gene lengths covering 274-438 amino acids in the VP2 gene which are collected from the NCBI database to investigate CPV epidemiology and diversity. The study highlighted substantial differences in seroprevalence over the period for CPV-2 (7%), CPV-2a (45%), CPV-2b (12%), and CPV-2c (36%). Our study found significant seroprevalence differences among CPV variants, with CPV-2a being the most prevalent, underscoring the need for effective diagnostic and preventive strategies.

Cross-Neutralization of Vanguard C4 Vaccine Against Australian Isolates of Canine Parvovirus Variants CPV-2a, CPV-2b, and CPV-2c.

Canine parvovirus type 2 (CPV-2) remains one of the most significant viral pathogens in dogs in Australia and worldwide despite the availability of safe and effective CPV vaccines. At least three different variants of CPV-2 have emerged and spread all around the world, namely CPV-2a, CPV-2b, and CPV-2c. The ability of the current vaccines containing either original CPV-2 type or CPV-2b variant to cross protect the heterologous variants has been well demonstrated in laboratory studies, despite some concerns regarding the vaccine efficacy against the emerging variants. Vanguard®, a series of multivalent vaccines, has been in the market for a considerable period of time and demonstrated to provide efficacy against all three types of CPV variants CPV-2a, CPV-2b, and CPV-2c. The purpose of this study was to evaluate the ability of the recently registered Vanguard C4 vaccine to induce cross-neutralizing antibodies against the Australian isolates of CPV-2a, CPV-2b, and CPV-2c variants. Blood samples collected from dogs vaccinated with Vanguard C4 were analyzed by virus neutralizing assays developed for each of three CPV variants. The results of the study demonstrated that Vanguard vaccine induced cross-neutralizing antibodies against the Australian isolates of CPV-2a, CPV-2b, and CPV-2c, thus offering cross protection against all three Australian CPV variants.

Canine parvovirus vaccination and immunisation failures: Are we far from disease eradication?

Despite extensive vaccination, canine parvovirus (CPV) remains a leading infectious cause of canine mortality, especially among juveniles. This review provides an update on CPV vaccine types and vaccination protocols. The design of CPV prevention strategies and vaccination programs with a goal of herd immunity has been hampered by deficiencies of studies that model companion animal viral infections and inform an understanding of the basic reproduction number. However, the most important issue in eradication of CPV disease is represented by immunisation failures including: i) the presence of interfering titres of maternally-derived antibodies; ii) the presence of non-responders; and iii) possible reversion to virulence. In contrast, the role of the CPV variants in immunisation failures is widely debated. Taking into account the reduced circulation of canine distemper virus and canine adenovirus type 1 in countries where extensive vaccination is carried out, more effort should be made to aim for CPV eradication, including antibody testing to determine the optimal time for vaccinations of pups and adults and homogeneous vaccine coverage of dog population.