HIV vaccines may 'harm' patients

HIV vaccines being developed may do patients more harm than good, studies in mice suggest.

The latest findings strengthen concerns that the adenoviruses being used in some experimental HIV vaccines could speed up T-cell exhaustion.

This would mean a HIV-positive patient would progress more rapidly to AIDS.

Recombinant adeno-associated viruses (rAAV) have been used as vectors to carry selected elements of the HIV-1 virus and act as a vaccine. The latest research could explain why clinical trials into such vaccines have so far led to disappointing results.

It focused on rAAV vectors of different serotypes, all of which expressed HIV-1 gag proteins - essential for virus replication.

The vaccines were injected into female mice, which received a primer and a booster injection one to two months later.

Follow-up assays on immune response demonstrated that CD8+ T cells produced in response to the vaccine poorly protected from infection in a challenge model.

They also proliferated poorly when they came into contact with their antigen.

Additionally, only low levels of the cytokine interferon-gamma were produced in response to gag stimulation.

If an rAAV-vector vaccine against HIV dampens immune response in this way, it could increase the recipient's susceptibility to AIDS by removing their natural immune defences, say the study authors.

Lead researcher Dr Hildegund Ertl, from the Wistar Institute Vaccine Center in Philadelphia, said: 'The results mean that rAAV vaccines against HIV may cause harm and that, without additional preclinical studies, they should not be used in humans.'

Have you registered with us yet?

Register now to enjoy more articles and free email bulletins

Register

Already registered?

Sign in

Follow Us:

Just published

GPs receive Queen's birthday honours

GPs receive Queen's birthday honours

GPs are among those who have been recognised in the Queen's birthday honours.

UK COVID-19 vaccination programme tracker

UK COVID-19 vaccination programme tracker

GPs across the UK are playing a leading role in the largest-ever NHS vaccination...

The healthcare crisis in Myanmar - how UK GPs can help

The healthcare crisis in Myanmar - how UK GPs can help

Dr Jim Brockbank from Myanmar UK GP Health Action provides an update on how the military...

GPs warn of 'open floodgates' as 84% say e-consultations have driven up workload

GPs warn of 'open floodgates' as 84% say e-consultations have driven up workload

More than four fifths of GPs say e-consultation systems adopted in the pandemic have...

Map: Which CCGs have the highest COVID-19 vaccine coverage?

Map: Which CCGs have the highest COVID-19 vaccine coverage?

Tens of millions of COVID-19 jabs have been administered across England, but how...

Podcast: Greener practice, sharing patient data and additional roles

Podcast: Greener practice, sharing patient data and additional roles

In this episode we look at data extraction from GP records, ask whether the additional...