A special dye that’s injected at the time of vaccination could become an alternative to paper or electronic vaccination records, researchers report.
“In areas where paper vaccination cards are often lost or do not exist at all, and electronic databases are unheard of, this technology could enable the rapid and anonymous detection of patient vaccination history to ensure that every child is vaccinated,” said Kevin McHugh, an assistant professor of bioengineering at Rice University, in Houston.
While he was a postdoctoral student at Massachusetts Institute of Technology (MIT), McHugh and his colleagues developed a dye that’s invisible to the naked eye and delivered under the skin at the same time as a vaccine.
The dye consists of nanocrystals called quantum dots and emits near-infrared light that can be detected by a specially equipped smartphone. The dye can remain under the skin for at least five years.
The dye is delivered by a microneedle patch rather than a traditional syringe and needle. Such patches are now being developed to deliver vaccines for measles, rubella and other diseases, and the dye could be easily incorporated into these patches, according to the researchers.
The report was published Dec. 18 in the journal Science Translational Medicine.
“In order to be protected against most pathogens, one needs multiple vaccinations,” said study senior author Ana Jaklenec, a research scientist at MIT’s Institute for Integrative Cancer Research.
“In some areas in the developing world, it can be very challenging to do this, as there is a lack of data about who has been vaccinated and whether they need additional shots or not,” Jaklenec noted in an MIT news release.
Laboratory tests with human skin showed that the quantum-dot patterns in the dye could be detected by smartphone cameras after up to five years of simulated sun exposure. Tests in rats showed that the immune response in those that received the dye with a polio vaccine in microneedle patches was similar to the response of those that received a traditional injected polio vaccine.
“This study confirmed that incorporating the vaccine with the dye in the microneedle patches did not affect the efficacy of the vaccine or our ability to detect the dye,” Jaklenec said.
The researchers plan further safety studies before testing the dye in humans, and not all animal studies bear out in humans.
The U.S. Centers for Disease Control and Prevention has more on vaccines and immunization.