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Page 25 Husein et al. One Health Implement Res 2023;3:16-29 https://dx.doi.org/10.20517/ohir.2022.32

Table 7. Assessment of staff involved in the study regarding the advantages and disadvantages of each vaccination method: oral
vaccination and parenteral vaccination using nets targeting free-roaming dogs
Vaccination methods Advantages Disadvantages
Oral vaccination Easy to do Takes a longer time to implement *
Could reach and vaccinate free-roaming Difficulties in feeding a group of dogs
dogs
Low risk of getting bitten Some dogs swallow bait directly without chewing
Requires little equipment Owners or local residents have concerns about this new
method
More fun There are no universally suitable baits
Capture-vaccinate-release (CVR) Dogs must be vaccinated if they are Dogs escape before being caught due to previous campaign
method caught trauma
Fast vaccination Heavy net to carry around
*
Easy to catch the dogs Difficult to implement
Guaranteed team safety Spreading skin diseases
Easy vaccine application Requires huge human resources and costs
*
Implement refers to approaching, catching and vaccinating the dog (CVR) and approaching and offering a bait to a dog, subsequent bait
consumption by the dog, followed, if applicable, by retrieving discarded sachet.

Bait acceptance is only one part of the requirement for the effective use of ORV. For ORV to be successful,
the contents of the sachet must be released in the oral cavity, where it will enter the body via the mucous
membrane and tonsils . In this and related bait acceptance studies, vaccination success was assessed by bait
[35]
handling and, if possible, visible staining of the oral cavity with the blue dye from the sachet [20,21,27,36] . The
validity of this approach has been previously confirmed by the presence of detectable antibodies during
serological studies when dogs were offered vaccine-loaded intestine - or egg baits [33,37,38] .

As has been observed in Thailand [20,34] , the estimated vaccination success of the egg bait was higher after bait
consumption than that of the intestine bait, partially compensating for the lower bait acceptance. Therefore,
it seems that the egg bait with or without local optimization (pet food paste/gravy) is an excellent bait
candidate achieving high vaccination rates in different settings all over the world, including Bali. The use of
a mass-producible vaccine bait has many additional advantages over baits made from local-available
material, including consistent quality and availability . The results obtained were in agreement with
[34]
previous studies using the same protocol. A significant effect on vaccination success was identified for the
different vaccination teams, ranging from 49% to 77%. A similar observation was made in Goa State,
India . It is not clear if the observed differences were caused by behavioral aspects of the vaccinators, such
[27]
as how they observed and approached the dogs, or if it was a result of variation in their assessment of bait
handling and subsequent “vaccination” success. There was no significant effect observed on vaccination
success against the increased experience of the teams taken over the 3 consecutive study days. Although the
vaccination success increased every day, most likely, the period was too short to have any significant effect.
In Turkey, a noticeable difference was found between a highly experienced team and inexperienced teams
consisting of veterinary students . The observed higher vaccination success in smaller-sized dogs was also
[39]
[20]
seen in Thailand . Bait acceptance and subsequent vaccination success were not influenced by the time of
bait offering, similar to the studies in the Navajo Nation, India, and Thailand [20,21,27] .

One of the requirements of the World Organisation for Animal Health (WOAH) concerning the use of
ORV is a risk assessment for human safety and the likelihood of human contact with the vaccine virus .
[40]
The risk assessment for human safety is not only influenced by the vaccine but also by the bait distribution
system. The system used during these bait acceptance studies is similar to the suggested hand-out and
retrieve model as practiced in Thailand . The baits were offered directly to the dogs encountered, and any
[34]