Scimex: US scientists have developed a painless, lesion-free method of delivering vaccines into the skin using arrays of microneedles combined with a laser. Delivering a vaccine into the skin, rather than muscle, has been proven to trigger a much stronger immune defense response against certain viruses.
A skin immunization strategy might help improve immune protection
against flu viruses and reduce mortality rates, according to a study.
The delivery of vaccines into skin rather than muscle is known to
produce stronger immune protection against some viruses. Yet skin
immunization has not been broadly adopted, partly due to relatively high
rates of pain and irritation and the difficulty of vaccine
administration. Mei Wu and colleagues developed a painless, lesion-free
strategy for delivering vaccines into skin using arrays of microneedles,
which are separated by sufficient distances to prevent the spread of
vaccine-induced inflammation and promote rapid healing. The authors
combined this approach with an approved nonablative fractional laser
(NAFL) treatment, which provokes a local, transient inflammatory
response that augments vaccine-induced immune protection. Mice that
received NAFL pretreatment at the inoculation site followed by
microneedle-array immunization with an H1N1 influenza vaccine survived
exposure to the H1N1 virus, whereas microneedle-array immunization alone
protected only 30% of mice. Moreover, the combination strategy
conferred a high level of cross-protection against other H1N1 viruses
and the H3N2 virus, increasing survival rates compared with
microneedle-array immunization alone. Because mismatches often occur
between vaccine and circulating strains of viruses, the cross-protection
offered by NAFL might enhance vaccine efficacy and reduce death rates
during the flu season, according to the authors.