How close are we to finding an HIV vaccine?

The hunt for an HIV vaccine in Uganda is younger than the hunt for rebel commander Joseph Kony of the disparaging LRA. Both have cost a lot of lives and money.

The hunts involve the international community, hope to put an end to the scourge soon, and are so far failing to hit the ultimate target, but insist, very hopefully, that the end is drawing nearer with each passing day.

But while Kony has killed thousands, HIV has claimed over 25 million people since 1981, according to the World Health Organisation. And efforts to eradicate it have included a lot more of research and trials consuming millions of dollars.

And, according to Dr. Hannah Kibuuka, the director at Makerere University Walter Reed Project (MUWRP) in Nakasero, big diseases are usually eradicated by vaccines. “Look at smallpox!” she says, “HIV prevention and treatment strategies are very important, but a successful vaccine would give us a magic bullet.”

World awareness day
Yesterday was the World HIV Vaccine Awareness Day. This annual observance is meant to recognise and thank the thousands of volunteers, community members, health professionals, and scientists, who are working together to find a safe and effective HIV vaccine. It is also a day to educate our communities about the importance of preventive HIV vaccine research.

In Uganda vaccine research efforts started as early as 1992, and according to Dr Juliet Mpendo, the medical director of the Uganda Virus Research Institute (UVRI), the very first HIV vaccine trial was conducted at the Joint Clinical Research Centre (JCRC).

“Since then, a number of trials have been conducted at various sites in collaboration with international organisations. We have conducted four HIV Vaccine trials so far,” she says.

Kibuuka adds that at MUWRP, two trials were conducted in 2004 and 2006.

The HIV vaccine
A vaccine is a biological preparation that contains an agent that resembles a disease-causing micro-organism. This agent stimulates the body’s immune system to recognise it as foreign and attack it not only to destroy it, but also to keep remembering it in case it returns later.

An HIV vaccine should trigger your body to produce antibodies that can recognise HIV and flush it out anytime it tries to enter the body.

The vaccine also trains the immune system to create a long-term squadron of antibodies that specifically seeks and destroys the same HIV, should it ever show its face.

Currently, there is no effective vaccine against HIV. But there is evidence that a vaccine may be possible. According to Kibuuka, science has proved that the human body can defend itself against HIV, and certain individuals remain physically fine for decades after HIV infection.

This shows that the human body can be induced to produce antibodies that either protect individuals from infection or keep the infection under control.

Why a vaccine
Today ARVs do exist and have benefitted many since their introduction in 1996. But they do not cure the patient of HIV. Other safer sex measures to halt the spread of HIV have proven difficult to implement.

Therefore, an HIV vaccine is generally considered as the most likely, and perhaps the only way by which the AIDS pandemic can be halted.

However, after over 28 years of research, HIV remains a difficult target for a vaccine.

Shall we ever get the vaccine?
According to Mpendo, the 2009 results of a vaccine trial in Thailand gave researchers hope that science was closing in on the virus. “This was the first time a vaccine showed a 31% protection effectiveness in preventing HIV infection,” she said.

Although the 31% reduction in the infection risk is too low for a usable vaccine (measles and polio vaccines are around 95% effective), it is a statistically significant effect.

The trial taught researchers that if we taught our immune systems to make antibodies early, we could destroy the virus before it gained a foothold.

Vaccine researchers are now working on ways of stimulating our T-cells to kill infected cells at an early stage. There is no telling when, or indeed if, these strategies will yield results, but what is certain is that the need for a vaccine will
not diminish.

“It may seem frustrating that decades of research have yielded nothing, but we must consider that it took 47 years to create a vaccine for polio and 42 for measles. For vaccine research, 28 years is not an inordinate amount
of time,” Kibuuka observes.

In the meantime
According to Dr. Kihuumuro Apuuli, the director-general of the Uganda AIDS Commission, while all these advances reinforce our confidence that one day a safe, highly effective HIV vaccine is possible, we should keep on exploring other ways of containing and ultimately halting the HIV/AIDS pandemic by using a combination of medical and behavioural prevention tools like ARVs, and expanded HIV testing with linkage to care, condoms, circumcision, abstinence and
faithfulness.

Early this month, the Uganda AIDS Commission, released a national prevention strategy, which aims at reducing HIV incidence by 40% by the year 2015.

“This will avert a total of 180,000 new HIV infections and virtually eliminate mother-to-child HIV transmission,” Kihuumuro told a roundtable discussion of stakeholders on Uganda’s Most at Risk Populations at the Golf Course Hotel on
May 4.

“We shall achieve this through expanding coverage and uptake of HIV prevention services, increasing adoption of safer sexual behaviours and reducing risk-taking behaviours as well as creating a sustainable enabling environment that mitigates the underlying socio-cultural and other structural drivers of the epidemic.”

Kihuumuro also called upon stakeholders to achieve a more coordinated HIV prevention response and strengthen information systems for HIV prevention at all levels.