Newer vaccines include synthetic, recombinant or highly purified subunit antigens that are weakly immunogenic. Therefore, these formulations require adjuvants for better immunologic efficiency. Immuno-modulators obtained from different sources such as synthetic, bacterial and viral have been used for enhancement of immune response to vaccines. Plant-based products are being considered as one option for immune adjuvants.

A new patent has been granted in the US for a vaccine adjuvant extracted from Ashwagandha (Withania somnifera ). It is used in Ayurveda as immunity enhancer. Researchers are also examining the immuno-modulatory activity of medicinal plants such as Shatavari and Guduchi.

The new adjuvant can be applied in ailmants like meningitis, diphtheria and tetanus among others.