Professor Carlos Barbas, III, says that tests on mice suggest that the vaccination method called covalent immunization can overcome a major drawback of vaccinations – the lag time of days, or even weeks, that it normally takes for immunity to build against a pathogen.

He revealed that his team tested the vaccination method on mice with either melanoma or colon cancer.

Describing the study in the Proceedings of the National Academy of Sciences (PNAS), the researcher said that the mice were injected with chemicals specifically designed to trigger a programmable and "universal" immune reaction.

They developed other chemicals, "adapter" molecules," that recognized the specific cancer cells.

The researchers said that after being injected into the mice, the adapter molecules self-assembled with the antibodies to create covalent antibody-adapter complexes.

"The antibodies in our vaccine are designed to circulate inertly until they receive instructions from tailor-made small molecules to become active against a specific target," Barbas says.

"The advantage of this method is that it opens up the possibility of having antibodies primed and ready to go in the time it takes to receive an injection or swallow a pill. This would apply whether the target is a cancer cell, flu virus, or a toxin like anthrax that soldiers or even civilian populations might have to face during a bioterrorism attack," adds the researcher.

Barbas revealed that only those mice that had received both the vaccine and the adapter compound generated an immediate immune attack on the cancer cells, which led to significant inhibition of tumour growth.

This is the first time that any research team have successfully designed and tested such a covalent vaccine.

"Our approach differs from the traditional vaccine approach in the sense that when we design an antibody-adapter compound we know exactly what that compound will react with," Barbas says.

"The importance of this is best exemplified with HIV. In current vaccines, many antibodies are generated against HIV, but most are not able to target the active part of the virus," the researcher adds.

He is currently planning future studies so that his team may apply their covalent vaccination approach to HIV, cancer, and infectious diseases for which no vaccines currently exist.