A novel adjuvant, the general opioid antagonist naloxone, elicits a robust cellular immune response for a DNA vaccine.

While many adjuvants have been discovered and used in research, only a few adjuvants have been permitted for use with human vaccination. We have previously shown that the administration of naloxone (NLX), a general opioid antagonist, during infection with a non-virulent strain of herpes simplex virus type 1 (HSV-1) could enhance protection against HSV-1 challenge. Here, the adjuvant activity of NLX has been evaluated using a DNA vaccine for HSV-1 as a model.

Naloxone, an opioid receptor antagonist, enhances induction of protective immunity against HSV-1 infection in BALB/c mice.

The immunomodulatory effects of exogenous opioids on induction of acquired immunity during microbial infection are now well known; however, our knowledge about the relationship between endogenous opioid response and microbial infections is rudimentary. Here, we report the effect of administration of Naloxone (NLX), an opioid receptor antagonist, on induction of acquired immunity during primary herpes simplex virus type 1 (HSV-1) infection. BALB/c mice received NLX, twice daily, 2 h before infection with HSV-1 until 7 days after infection.