New research indicates that using a particular laser to pre-treat the site of a flu shot may boost the body’s immune response against influenza. In the open-access journal PLOS ONE, investigators from the Vaccine and Immunotherapy Center in the MGH Division of Infectious Diseases report that in a mouse model, a one-minute dose of near-infrared laser light significantly improved the effectiveness of intradermal flu vaccine – a flu vaccine injected into the skin rather than the muscles beneath the skin.
“We believe the laser causes skin cells to release chemical signals that draw immune system cells to the area of the vaccination,” says Mark Poznansky, MB ChB, PhD, director of the MGH Vaccine and Immunotherapy Center and senior author of the report. “Those cells prime the immune system to respond to the incoming influenza antigens and generate antibodies against them, resulting in boosted vaccine effectiveness.”
Currently, chemical additives called adjuvants are often paired with vaccines to create the same effect. However, these chemical adjuvants can result in such side effects as pain and swelling at the vaccination site,
so many flu shots do not have them.
“Without adjuvants, many vaccines – including the flu shot – are not as effective as they could be,” explains Satoshi Kashiwagi, MD PhD, of the Vaccine and Immunotherapy Center, lead and co-corresponding author of the PLOS ONE report. “Our results indicate that laser light could be a safe alternative to these adjuvants, resulting in a more effective vaccine without any undesirable side effects.”
The researchers have done a safety trial of the laser on people and hope they can test it in clinical trials soon. “The key thing we’re going to look at is how to accelerate the development of this new adjuvant for vaccines and immunotherapy,” Poznansky says.
Long term, they hope to explore using lasers as adjuvants for vaccines against hepatitis B, HPV and cancer.
Read more articles from the 01/10/14 Hotline issue.