Infants may soon be drinking their vaccines in fruity flavors that will not only appeal to the palate but may prove economical as well.

In the past four years, scientists at the College of Public Health of the Institute of Plant Breeding, UP Los Baños, have been developing edible vaccines against typhoid fever, and the human immunodeficiency virus (HIV).

The team of Dr. Nina Gloriani Barzaga of the Microbial Immunology Research Group has cultures tomato plants at the UP Los Baños that will encoded with vaccine antigens or agents which, will provide the needed stimulus to induce the immunity response of a person against typhoid fever and HIV.

Barzaga said that once the cultures plants have passed the laboratory stage, the scientists will transfer the plants in a contained greenhouse for evaluation. She said they are waiting for the bio-safety clearance so they can inject the antigens into the cultures plants.

After the evaluation comes animal testing then human testing and finally, commercialization of the product.

"It is actually more economical than traditional vaccines because the ones that we have now uses fermentors and a lot of equipment and infrastructure. But with edible vaccine, even if we are in the third world, we can have a lot of plantation," Barzaga said.

Plant biochemist Dr. Antonio C. Laurena explained that they also cultures banana plants early in the experiment. The banana plants, due to lack of proper infrastructures, were contaminated and had to be destroyed. He, however, said they will continue to culture banana plants for the same project later.

He said an edible vaccine for rabies is also being studied.

Once completed, the edible vaccine will be transformed into powder form and will be put in sachets containing the required exact concentration of the vaccine. It can be mixed in food or can be drunk like an ordinary juice.

The Philippines is one of the first countries to develop edible vaccines along with Japan, while the United States is on the human trial phase of the project.

"The edible vaccines will be regulated as pediatricians will be the ones who will prescribe this. A prescription will be needed to purchase the edible vaccines," Barzaga said.

Asked whether they are ready to meet the reactions of the church and other sectors on the HIV vaccine for children, Laurena said that they are more concerned on the number of people who may acquire the disease should a pandemic occur.

"There can be a pandemic of HIV and we don't want Filipinos to acquire this because they can get infected even without sex, by blood transfusion, for instance."

The development of these edible vaccines may take from 10 to 15 years because of the lack of funds. However, Barzaga said it may be possible to hasten the development of the project in the next four years if they could raise enough funds - an estimated P100 million - to support the project.