Experimental calf vaccine shows promising results against crypto

An experimental vaccine for Cryptosporidium parvum (crypto) from MSD Animal Health has shown positive results.

At the European Buiatrics Congress and ECBHM Jubilee Symposium 2023, MSD outlined what it described as two sets of pivotal field study data evaluating the efficacy of its experimental vaccine to provide protection against crypto in new-born calves.

Crypto is highly infectious and is passed on to other calves when they ingest oocytes that have been residing in the environment or shedded from an infected calf.

It is usually seen in young calves between one- and four-weeks-of-age. It is a life-threatening scour and can cause a calf to quickly deteriorate if left untreated.

The symptoms occur rapidly; calves begin to scour and shed huge quantities of oocytes in the dung to the surrounding area. They become severely dehydrated, weak and find it difficult to get up.

Some calves can become infected and do not show any signs, but still spread the infection through the oocytes in their dung.

Crypto

The data which was presented at the symposium evaluated the experimental crypto vaccine for protection against C. parvum infection in neonatal calves by passive immunisation.

Global technical director of ruminant biologicals at MSD, Geert Vertenten said:”Cryptosporidium parvum is a highly infectious zoonotic parasite that is associated with neonatal calf diarrhoea, the leading cause of calf morbidity and mortality.

“There is a critical need to treat and prevent this harmful infection.”

In the study, healthy pregnant heifers were given the experimental crypto vaccine and Bovilis Rotavec Corona during the third trimester of pregnancy.

After the calves were born, researchers collected colostrum from the vaccinated heifers, then randomly assigned viable new-born calves to receive the colostrum within four hours of birth before being exposed to C. parvum oocysts up to four hours later.

The results showed that new-born calves fed with colostrum from crypto-vaccinated heifers had a significantly lower chance of having diarrhoea, as measured by health and diarrhoea scores.

Antibodies

MSD also shared a second set of analyses that investigated the antibody response of the same crypto vaccine in cattle in relation to C. parvum parasitic infection stages and an in-vitro infection model.

The results showed that high level anti-gp40 in vitro neutralising antibodies were significantly increased in animals that were given the crypto vaccine compared to the non-vaccinated control group.

This data, according to MSD, further validate that gp40 is an important protein expressed on the exterior of different C. parvum infection stages.

Associate vice-president of the global ruminant business at MSD, Philippe Houffschmitt stated that MSD is taking the lead in protecting cattle against the most common and harmful pathogens.

He said it also offers solutions that guide herd management decisions to help improve animal welfare and operational efficiency.

Houffschmitt said: “That responsibility begins with equipping those in bovine herd health management with the tools they need to keep animals healthy and minimise the need for treatment.

“We are excited to share our latest research in C. parvum prevention, which we hope adds to the growing body of scientific evidence that is enhancing the comfort and care of livestock and helping bovine production medicine specialists make better decisions about health interventions for animals.”