Since their inception, vaccines have been a boon to human populations helping to reduce diseases such as polio, smallpox, and measles. However, for infections such as malaria and HIV-1 the efficacy of vaccines reduces drastically. This is sometimes related to the timing of antigen and adjuvant reaction to the immune system.
A paper recently published in the journal ACS Central Science discusses development of an injectable hydrogel. The use of injectable hydrogel ensures sustained release of vaccine components, thereby improving quality, potency, and duration of immune response in mice.
Function-wise, most vaccines work by exposing the immune system to elements of a pathogen for a period of time. This enables the body to generate antibodies to fight the infection. Later, on encountering the same pathogen, the immune system of the vaccinated person can recognize and dispose of the invader more quickly involving less effort.
Exposure of Immune system to antigens longer for Natural Infection
Meanwhile, for natural infections, typically, the immune system is exposed to antigens for 2-3 weeks; on the other hand, vaccines rarely give more than 1-2 days of exposure to antigens. This may be perfectly sufficient for some infections, but it may be lacking for others.
To find a solution to this, a team of researchers set out to develop an injectable hydrogel that would discharge vaccine components over a longer period of time. The state is like that for natural infections, to hopefully result in a stronger immune response.
For the study, the research team described a vaccine-infused polymer-nanoparticle hydrogel. The team had injected tis hydrogel under the skin of mice. As a result of injection, it resulted in localized inflammation which brought certain types of immune cells to the area of injury.