Scientists have created an influenza vaccine delivered via microneedle patch that provided 100 percent protection against a lethal influenza virus in mice more than 1 year after they were vaccinated.
Microneedles are a medium for delivery of influenza vaccine that avoids the pain associated with ordinary hypodermic needles. They are a mere seven tenths of a millimeter in length, and the volume of vaccine-a major contributor to pain-is minuscule.
Instead of a liquid containing whole killed or attenuated virus, this vaccine uses dry virus-like particles (VLPs) which simply coat the needles in the presence of a simple stabilizing agent, reducing the need for refrigeration - a potential boon for use in developing countries.
The lower dose required when using microneedles also reduces the potential for side effects, such as lung inflammation.
Earlier studies by this group showed that influenza VLP-coated microneedles actually produced higher short-term protection than conventional intramuscular immunization.
In this study the researchers tested how effective the long-term protection of the vaccine was. Mice that received the vaccine were 100 percent protected from a lethal challenge with the influenza virus 14 months after vaccination.
The study has been published in the journal Clinical and Vaccine Immunology.