London - Researchers announced the launch
of two big studies in Africa on Thursday to test a new HIV
vaccine and a long-acting injectable drug, fuelling hopes for
better ways to protect against the virus that causes AIDS.
The start of the three-year vaccine trial involving 2,600
women in southern Africa means that for the first time in more
than a decade there are now two big HIV vaccine clinical trials
taking place at the same time.
The new study is testing a two-vaccine combination developed
by Johnson & Johnson (J&J) with the U.S. National
Institutes of Health (NIH) and the Bill & Melinda Gates
Foundation. The first vaccine, also backed by NIH, began a trial
last November.
At the same time, GlaxoSmithKline's majority-owned
ViiV Healthcare unit is starting another study enrolling 3,200
women in sub-Saharan Africa to evaluate the benefit of giving
injections every two months of its experimental drug
cabotegravir.
The ViiV initiative, which is expected to run until May
2022, also has funding from the NIH and the Gates Foundation.
Women are a major focus in the fight against the sexually
transmitted disease since in Africa they account for more than
half of all new HIV infections.
ViiV is also running another large study with its
long-acting injection in HIV-uninfected men and transgender
women who have sex with men. That study started in December
2016.
Although modern HIV drugs have turned the disease from a
death sentence into a chronic condition and preventative drug
treatment can help, a vaccine is still seen as critical in
rolling back the pandemic.
The latest vaccine experiments aim to build on the modest
success of a trial in Thailand in 2009, when an earlier vaccine
showed a 31 percent reduction in infections.
"We're making progress," said J&J Chief Scientific Officer
Paul Stoffels, who believes it should be possible to achieve
effectiveness above 50 percent.
"That is the goal. Hopefully, we get much higher," he told
Reuters.
The new vaccines require one dose to prime the immune system
and a second shot to boost the body's response.
Significantly, J&J's latest vaccine uses so-called mosaic
technology to combine immune-stimulating proteins from different
HIV strains, representing different types of virus from around
the world, which should produce a "global" vaccine.
One reason why making an HIV vaccine has proved so difficult
in the past is the variability of the virus.
Initial clinical results reported at an AIDS conference in
Paris in July showed the mosaic vaccine was safe and elicited a
good immune response in healthy volunteers.
Some 37 million individuals around the world currently have
HIV and around 1.8 million became newly infected last year.