Since the discovery of the human immunodeficiency virus (HIV) in 1981 which causes a spectrum of infections and diseases associated with acquired immunodeficiency syndrome (AIDS), the two things that have been eluding scientists for four decades.
One, how to prevent it by developing an effective vaccine and the second, curating a cure.
Whilst a plethora of wide-ranging research has shown some promising results on possibilities of a cure if the disease is detected early, vaccine development is still, unfortunately in a rudimentary phase.
However, this could change soon as human trials for an mRNA vaccine, proposed by Moderna and its partners such as IAVI and Scripps Research, have been approved.
Why is it So Elusive?
HIV thwarts any endeavours made by our body’s immune system to counter it. By adopting a mechanism of swift-evolution, deceiving and evading the antibodies.
Over time the virus has enhanced these measures to such an extent that it can often camouflage its outer layer, known as envelope glycoprotein, with sugar chains spotted on proteins in humans, and thus effect a neat disguise.
Very much akin to the coronavirus, it utilizes the spike proteins embedded on it to ensnare the host cells, thereby infecting them as they attach themselves.
The Proposed Workaround by Moderna & Associates
IAVI and Scripps Research claim that they’ve come up with an imperative key to the larger puzzle that has been flummoxing everyone for the last four decades.
They’ve reportedly engineered an immunogen that resembles the visage of the HIV envelope glycoprotein (HIV env).
An immunogen is essentially an antigen on either antibodies or other immune system entities, that have the potential to elicit an appropriate immune response.
This immunogen can induce certain immature B cells to develop neutralizing antibodies that can broadly safeguard the body before the threat materializes.
It has been statistically surmised that around 10-20% of people possess the capacity to produce these neutralizing antibodies on their own after several years.
The present mRNA-1664 expected vaccine has found these results after arduous study in the lab and on animal subjects, followed by humans.
The preliminary human study was conducted on 48 healthy people who were HIV-negative and partook willingly. They received two doses of artificially contrived protein-based immunogen or even a placebo, pegged two months apart.
Results were presented at the HIV Research for annual prevention meeting, which revealed that about 97% of the people produced the desired response, genesis of specific immature B cells with no detrimental breakdown.
Further Developments & Scope
The upcoming trials commencing from the third week of September will entail 56 adults between age groups of 18-40. They’ll be divided into 4 groups and are slated to receive the mRNA-1644 vaccine solution or mRNA-1644v2-core antigen or even both.
It will involve a phase-wise approach: the first, and the primary being successful production of the requisite immature B cells in the host bodies.
Secondly, they’ll be navigated by the broadly neutralizing antibodies to a specific site known as the CD4 binding site on the HIV env.
It is estimated that this study will persist for 19 months and Moderna (which had developed a COVID-19 vaccine too) will help in active succour for discovery and development.
Experts’ Opinions on mRNA HIV Vaccine
Feinberg opines that the novel idea of introducing neutralizing antibodies to target specific structures has its challenge and that this is “germline targeting”, intended to “prime” the young B cells in a strategy that is still somewhat obscure and conjectured to occur in multiple steps.
Dr Mohammed Sajadi, MD, an associate professor of medicine at the University of Maryland’s Institute of Human Virology, also complies with Feinberg’s views.
He says that it is still not abundantly clear how many people can naturally concoct the required antibodies or even artificially with the help of a vaccine.
Furthermore, there is dubiousness on whether it will efficacious and durable or not.
The virus is uncannily very dynamic — it metamorphosizes itself with time, making it all the more sophisticated in charting a particular stratagem to tackle it.
Although, the test results seem to be promising and a “lot could be learned from the first step” which checked for elicitation of a suitable response of antibody titers or the number of cells activated.
Even though it is frustratingly cumbersome to arrive at a definitive ploy to solve the problems, this could be a harbinger to an ultimate solution, Dr Sajadi adds.
