Many of the most important scientific breakthroughs of the past century have included vaccine production to protect against viruses, such as:
- hepatitis A and hepatitis B
- human papillomavirus (HPV)
- But one virus still thwarts those who want to create a vaccine to guard against it: HIV.
1984 was the first time HIV was reported. Around the time, the U.S. Department of Health and Human Services reported that they had hoped a vaccine would be available within two years.
Following several potential vaccine trials, however, there is still no truly effective vaccine available. Why is the disease so hard to conquer? And where do we stand in the process?
Obstacles to an HIV vaccine
Developing an HIV vaccine is so difficult since it is isolated from other virus types. HIV does not suit typical approaches to vaccines in several ways:
- The immune systems of almost all people are ‘blind’ to HIV
The immune system that fights disease does not respond to the Virus of HIV. This produces antibodies to HIV which only slows down the disease. They are not stopping him.
- Vaccines are usually made to replicate the immune reaction of recovered people
Though, after contracting HIV almost no people have recovered. As a result, there is no immune response that can replicate the vaccines.
- Vaccines protect against disease and not against infection
HIV is a stage 3 virus, or AIDS before it progresses. Like other diseases, vaccines give the body more time before the illness happens to clear the infection on its own accord.
HIV, however, has a long-dormant period until it progresses toward AIDS. At this time the virus covers itself with the virus in the person's DNA. The body can not locate and kill any of the virus' secret copies for its own cure. But a vaccine that purchases more time does not work with HIV.
- Can't use killed or destroyed HIV viruses in a vaccine
Most vaccines are made with either destroyed or debilitated viruses. However, killed HIV doesn't function well in the body to create an immune response. Any live form of the virus is too dangerous to use.
- Usually, vaccines are effective against diseases rarely encountered
Among others are diphtheria and hepatitis B. Yet people with identified HIV risk factors may be exposed to HIV every day. This means that there is a greater risk of infection which a vaccine can not prevent.
- Most vaccines use respiratory or gastrointestinal systems to protect against viruses that enter the body
In these two cases, more viruses are reaching the body and we have more expertise in handling them. Yet HIV most often gets into the body through genital surfaces or blood. They have less expertise in fighting against the viruses that thus penetrate the body.
- Most vaccines are carefully tested on animal models
It assists in ensuring that they are likely to be safe and successful before being tested on humans. There is no good animal model suitable for HIV however. Any animal research hasn't shown how humans will respond to the vaccine being tested.
Prophylactic vs. therapeutic vaccines
Scientists intend to try to find a vaccine amid those hurdles. There are two main vaccine types: prophylactic and therapeutic. Investigators are now suing for HIV.
Many vaccines are prophylactic, meaning they protect a person from becoming ill. On the other hand, therapeutic vaccines are used to improve the body's immune response to the disease the person already has. The vaccinations are also called preventive vaccines.
There are many factors under review for therapeutic vaccines, such as:
- cancerous tumors
- hepatitis B
- the bacteria that cause gastric ulcers
By principle, a vaccine against HIV will have two aims. Next, people who don't have HIV should be given medication like tenvir to prevent the infection from contracting. That would make this vaccine a prophylactic one.
Yet HIV is also a successful therapeutic vaccine candidate. Researchers are hoping a therapeutic HIV vaccine could reduce the viral load of a patient.
Types of experimental vaccines
Researchers are working to create an HIV vaccine using several different methods. There are new vaccines being investigated for both prophylactic and medical uses.
Researchers currently work on the following types of vaccines:
Peptide vaccines use tiny HIV proteins to cause an immune response.
Recombinant subunit protein vaccines use bigger bits of HIV antigen.
Using non-HIV viruses, live vector vaccines bring HIV genes into the body to cause an immune response. This process is used in the smallpox vaccine.
Variations of vaccines, or variations of the "prime-boost," use two vaccines one after the other to create a stronger immune response.
Virus-like particle vaccines use a non-infectious HIV look-alike that has some HIV proteins but not all.
DNA based vaccines use HIV DNA to cause an immune response.
Clinical trial stumble
A research on the HIV vaccine, dubbed the research HVTN 505, began in October 2017. A prophylactic approach that used a live vector vaccine was tested.
A weakened cold virus called Ad5 was used to activate the immune system to recognize HIV proteins (and thus be able to fight them). To be part of the study more than 2,500 people were recruited.
The study was halted after researchers found the vaccine did not prevent or decrease the viral load from transmitting HIV. In reality, 41 people contracted HIV on the vaccine, whereas only 30 people contracted HIV on a placebo.
There's no proof that the vaccine has raised people's risk of contracting HIV. Nevertheless, with the previous Ad5 failure in a study called STEP in 2007, researchers were worried that something that induced immune cells to target HIV could increase the risk of contracting the virus.
The future of HIV vaccines
In 2017, $845 million had been spent on HIV vaccine studies, according to a 2018 estimate. And so far, it has tested more than 40 possible vaccines.
Progress toward a workable vaccine has been slow. Yet more is gained with each failure which can be used in new attempts.
A healthcare professional is the best place to start with responses to questions about an HIV vaccine or guidance on taking part in a clinical trial. They will answer questions and provide specifics of any clinical trials that might suit well. When purchasing medicine online, we recommend safe healths pharmacy it is a trusted online pharmacy.