Would you rather be pierced with a needle or eat a banana? The world's biotechnology industries are trying to give you that choice when you need a vaccination. It involves changing the genetic blueprint of a plant so that it can produce the vaccine as it grows. All the recipient has to do is eat the plant to receive the vaccination.

All of the technologies required to do this are available now. The world's pharmaceutical industries have been using genetically engineered yeasts and bacteria for years to produce drugs and medical preparations such as penicillin, insulin and interferon.

Plants can also be engineered to produce "foreign" substances such as medicines or vaccines. The Hepatitis B vaccine for example can be derived from plants.

There is no reason in theory why a banana plant or any other fruit can't be engineered to do this. A group of researchers in Cornell University in New York State this month received one of six grants worth $5 million (£3.42 million) to find ways to use these technologies to reduce healthcare costs. The Cornell group has already created an oral vaccine that protects against a viral infection in mice.

The work will target sexually transmitted diseases in particular according to Dr Mark Saltzman, who leads the Cornell group. These oral delivery systems "will be important in the next generation of vaccines" he says.

Many vaccines are made from animal materials which are expensive and time-consuming to produce. The need to inject these also means they must be very highly purified. Vaccines entering a person's stomach do not require such a high level of purity to work properly.

The genetic engineering of plants used to produce foodstuffs have been vigorously opposed by lobby groups who believe more research is needed before the technology comes into play.

A recent flashpoint between promoters and opponents was provided by Monsanto's Environmental Protection Agency approved field trials of a sugar beet plant that was engineered so it could tolerate herbicides. An unknown group mounted an overnight raid earlier this month on trial fields and all of the test plants were cut down and destroyed.

The pressure behind the development of this technology in the pharmaceutical, health care and agricultural areas looks unstoppable however. International companies are wary about resistance from consumers to modified foods but research continues nonetheless. And most new pharmaceutical products are being developed for production using biotechnology techniques.

As to choosing between a needle or a light snack, all of the technology already exists, all that is needed is the decision to do it and the funding to make it happen.