HYDERABAD: The novel adjuvant being used to boost the immune response of indigenously developed Covaxin was developed with funding from the National Institute of Allergy and Infectious Diseases (NIAID) that is headed by leading infectious diseases expert Dr Anthony S Fauci, the National Institutes of Health (NIH) has said.
"An adjuvant developed with funding from the NIH has contributed to the success of the highly efficacious Covaxin Covid-19 vaccine, which roughly 25 million people have received to date in India and elsewhere," NIH said. Adjuvants are substances used to boost immune responses and enhance a vaccine's effectiveness.
The top US health body said the adjuvant, Alhydroxiquim-II, was discovered and tested by Kansas-based biotech company ViroVax LLC with support exclusively from the NIAID Adjuvant Development Programme that has been supporting Dr David's research since 2009. NIAID is a part of NIH and ViroVax is headed by Indian American Dr Sunil David.
"Ending a global pandemic requires a global response. I am pleased that a novel vaccine adjuvant developed in the United States with NIAID support is part of an efficacious Covid-19 vaccine available to people in India," said NIAID director Dr Fauci, who is also chief medical advisor to the US President.
Explaining how Alhydroxiquim-II works, NIH said it comprises a small molecule that is attached in a unique way to Alhydrogel, which is commonly referred to as alum and used as an adjuvant in human vaccines.
Alhydroxiquim-II travels to the lymph nodes, where the small molecule detaches from alum and activates two cellular receptors -- TLR7 and TLR8 - that play a vital role in evoking an immune response to viruses. In addition, the alum in Alhydroxiquim-II stimulates the immune system to search for an invading pathogen, NIH said.
The US health body also pointed out that Allhydroxiquim-II is the first adjuvant to be used in an authorised vaccine against an infectious disease to activate TLR7 and TLR8.
"Molecules that activate TLR receptors stimulate the immune system powerfully, but the side effects of Alhydroxiquim-II are mild because after Covaxin is injected, the adjuvant travels directly to nearby lymph nodes, which contain white blood cells that play an essential role in identifying pathogens and fighting infection," it explained.
"Consequently, only a small amount of Alhydroxiquim-II is needed in each dose of vaccine, and the adjuvant does not circulate throughout the body, thereby averting more widespread inflammation and undesirable side effects," it added. The NIH statement comes even as Ocugen is gearing up to file a biologics license application (BLA) with the United States Food & Drug Administration (USFDA).
