New Type of HIV Vaccine Works in Monkeys Trials
Have you heard about the new type of HIV vaccine and how it works in Monkeys? Do you know how it is useful in substantially enhancing and sustaining protection from HIV in monkeys? Probably not. If you are interested in finding out the impact of this new vaccine in monkeys, keep reading.
A new type of HIV vaccination has been proposed to enhance and sustain protection from HIV in monkeys significantly. The principal objective of this vaccine is its ability to improve the immune system in the monkeys. Most of the vaccines lack this ability and are less effective in providing the necessary protection.
Vaccine Orientated Towards Fighting with Both Arms
Even after decades of thorough research and analysis, scientists haven’t succeeded in making an HIV preventive vaccine. Generally, vaccines are designed to strengthen the immune system of an individual. The immune system responds by generating cells and molecular weaponry that targets a particular pathogen.
The adaptive immune response comprises of two arms:
- Serum Immunity
- Cellular Immunity
In serum immunity, the B-cells secrete antibodies that catch and neutralize a microbial pathogen.
In cellular immunity, the killer T cells move throughout the body in search of viruses. Once found, they destroy the cells that nourish them.
All the vaccines made up to date work by including antibodies that function to neutralize a virus. However, when it comes to maintaining a high level of neutralizing antibodies against HIV, it is quite a challenging task. The researchers claim that by stimulating the cellular arm of the immune system, you can get more robust protection against HIV, surprisingly even with lower levels of neutralizing bodies.
Most of the vaccines today rely on the adaptive immune system to deal with the infections using one of the arms and the other tied behind its back.
In this new study, the researches employed a two-armed approach. They worked on stimulating both serum and cellular immunity. The research involved incorporating 3 groups of 15 rhesus macaques for 40 weeks.
The first group received some sequential inoculations of Env and adjuvant.
Env is a protein found on the virus’s outer surface and is known to stimulate antibody production. On the other hand, an adjuvant is a chemical often used in vaccines to boost the overall immune response.
Similarly, researches incorporated the second group, but the difference was that they gave them additional injections of three different kinds of viruses. Each of these viruses was infectious but wasn’t dangerous. Each modified virus contained an additional gene for a viral protein, Gag, that is known to stimulate cellular immunity.
Finally, a third group was named as the control group, was given the injections containing adjuvant only.
How it Helped in Providing Better Protection Against HIV?
At the end of the 40 weeks, all animals were allowed to rest for an additional 40 weeks. After that, they were given booster shots of just the Env inoculation. They were allowed to rest for four weeks, after which they were subjected to 10 weekly exposures of SHIV, which is a simian version of HIV.
Resultantly, the monkeys that only received adjuvant became infected. Whereas, the animals with both Env and Env-plus-Gag groups experienced significant protection from viral infection.
The scientists have generally considered the serum immune response to be the defining source of a vaccine’s effectiveness.
After 20 weeks, six monkeys from the Env group and 6 from the Env-plus-gag group experienced additional exposures to SHIV. However, this time four from the Env-plus-gag animals and one from the Env animals remained unaffected.
The researchers claim that this improvement resulted from vaccine-stimulated production of immune cells called tissue-resident memory T cells. These cells reach the site from where the virus enters the body and stay there for a specified period serving as sentinels.
If these cells see the virus again, they perform their action by signaling other immune-cell types in the vicinity and turn the tissue to the hostile territory for the virus.
Hence, the results suggest that future vaccination efforts should focus on strategies that are oriented towards both cellular neutralizing-antibody response. That’s how the new vaccines can provide superior protection against HIV and other such pathogens, e.g. tuberculosis, malaria, the hepatitis C, and even the pandemic coronavirus.
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