Vaccination against coronaviruses in domestic animals

Abstract

The current pandemic of COVID-19 has set off an urgent search for an effective vaccine. This search may well benefit from the experiences of the animal health profession in the development and use of coronavirus vaccines in domestic animal species. These animal vaccines will in no way protect humans against COVID-19 but knowledge of the difficulties encountered in vaccinating animals may help avoid or minimize similar problems arising in humans. Diverse coronaviruses can infect the domestic species from dogs and cats, to cattle and pigs to poultry. Many of these infections are controlled by routine vaccination. Thus, canine coronavirus vaccines are protective in puppies but the disease itself is mild and self-limiting. Feline coronavirus infections may be mild or may result in a lethal immune-mediated disease-feline infectious peritonitis. As a result, vaccination of domestic cats must seek to generate-protective immunity without causing immunemediated disease. Vaccines against bovine coronavirus are widely employed in cattle where they protect against enteric and respiratory disease in young calves. Two major livestock species suffer from economically significant and severe coronavirus diseases. Thus, pigs may be infected with six different coronaviruses, one of which, porcine epidemic diarrhea, has proven difficult to control despite the development of several innovative vaccines. Porcine epidemic diarrhea virus undergoes frequent genetic changes. Likewise, infectious bronchitis coronavirus causes an economically devastating disease of chickens. It too undergoes frequent genetic shifts and as a result, can only be controlled by extensive and repeated vaccination. Other issues that have been encountered in developing these animal vaccines include a relatively short duration of protective immunity, and a lack of effectiveness of inactivated vaccines. On the other hand, they have been relatively cheap to make and lend themselves to mass vaccination procedures.

The Coronaviruses of Animals and Birds: Their Zoonosis, Vaccines, and Models for SARS-CoV and SARS-CoV2

“…For instance, the IBV vaccines were the first licensed vaccines to prevent upper respiratory CoV infection in chickens (52,53). The compiled data generated during the experiments with animals CoV vaccination programs are an invaluable source of designing an effective vaccine to SARS-CoV2 (54). Hence, CoV vaccines of veterinary applications highlight numerous successes, potentially allowing the hurdles that are faced in the development of a SARS-CoV2 vaccine to be negotiated (55,56).…”

“…Despite this fact, live vaccines could revert to a virulent strain (58) and have low efficiency in preventing virus shedding. Inactivated vaccines induce partial mucosal immunity; however, they are a good booster of immunity in sows prior to farrowing (54). Other issues that have been taken into consideration while vaccines development are the short duration of protective immunity and poor inactivated vaccine potency.…”

“…Other issues that have been taken into consideration while vaccines development are the short duration of protective immunity and poor inactivated vaccine potency. On the other hand, these types of vaccines are low cost, especially in the veterinary field, where mass vaccination procedure is practiced (54). The development of recombinant vaccines by using reverse genetics as an attenuation approach has been advocated (54).…”

“…On the other hand, these types of vaccines are low cost, especially in the veterinary field, where mass vaccination procedure is practiced (54). The development of recombinant vaccines by using reverse genetics as an attenuation approach has been advocated (54). In addition, recombinant subunit vaccines are also seen as important to produce proteins expressed genetically in modified Escherichia coli based on recombinant DNA technology (60).…”

“…Fulker et al (1995) have stated that a small number of vaccinated dogs (15%) show very mild diarrhea while 80% of the non-vaccinated dogs show severe watery or bloody diarrhea experience with an average of about 10.8 days compared to 1.4 days for vaccinated animals (62). However, the mild status of the disease discouraged the wide application of the vaccine (54). Despite the availability of both inactivated and modified live vaccines against the group 1 virus, their use is not recommended because the infection is mostly mild and self-limiting, with inapparent gastroenteritis, anorexia, fever, and diarrhea.…”