New research by Trinity College Dublin suggests that AstraZeneca’s Covid-19 vaccine may have added health benefits, protecting people from more than just the virus.

According to the findings, the vaccine may also boost immune responses to bacterial infections as part of a phenomenon known as “trained immunity”. The researchers found that this phenomenon occurred in people after receiving their first dose of AstraZeneca and was still present up to three months later.

The vaccine appeared to increase the recipient’s innate immune response to bacterial infections, with enhanced production of key molecules called cytokines and chemokines, which mediate effective immune responses resulting in the killing of bacteria and virally-infected cells. 

AstraZeneca is an adenovirus vectored vaccine, which works in a different way to mRNA vaccines, such as the Pfizer and Moderna Covid vaccines. According to Dearbhla Murphy, a PhD student in the Basdeo Lab at Trinity College who undertook this research, these findings “will help us understand the broader effects of vaccination with adenovirus platforms and may guide the design of a ready-to-use vaccine platform that can be rapidly developed to protect us against emerging infectious diseases”.

“The off-target protection from the vaccine is especially exciting as it could promote general good health and boost our immune systems, reducing the incidence of other infections and our reliance on antibiotics,” she noted.

According to the study’s senior author, Dr Sharee Basdeo, principal investigator of the Human and Translational Immunology Group based in the Trinity Translational Medicine Institute at St James’s Hospital, this research may have a big impact.

“The role of innate immunity in promoting post-vaccine health is not yet fully appreciated. Therefore, tracking innate as well as traditional adaptive immune responses to vaccination against emerging infections may help to identify optimal vaccine platforms, boost regimens and limit serious side-effects.

“Our work improves the understanding of the contributions of innate immune function to specific and non-specific effects of vaccines and may lead to the development of innovative vaccine design for difficult-to-treat infectious diseases that remain a global threat to public health,” she commented.

The study is published in The Journal of Clinical Investigation can be viewed here.