Navigation Links
Progress made in HIV vaccine development

Researchers have successfully tested two candidate vaccines that may eventually be used together to confer immunity against HIV infection. Their findings are published in the December 15 issue of The Journal of Infectious Diseases, now available online.

Barney S. Graham, MD, PhD, and colleagues from the National Institutes of Health IH Vaccine Research Center in Maryland, the Fred Hutchinson Cancer Research Center in Seattle, and GenVec Incorporated tested two possible HIV vaccines with the hope of producing an immune response in healthy, uninfected adults. One was a plasmid DNA-based vaccine expressing genes from three dominant HIV subtypes, and the second used recombinant adenovirus serotype 5 (rAd5) as a vector to deliver similar HIV strains.

"Both approaches operate by gene delivery of customized vaccine antigens that are produced by host cells to initiate an immune response. DNA is simple and does not have the problem of anti-vector immunity. However, DNA may be less potent than vector-based gene delivery strategies. Replication-defective rAd5 has the advantage of targeted, efficient gene delivery and high potency, but may be susceptible to anti-vector immunity," said Graham.

Both vaccines were tested in healthy uninfected adult volunteers. The DNA vaccine was found safe and well-tolerated. By week 12 following immunization, 97.5% of vaccinees experienced positive CD4 T cell responses and 40% experienced positive CD8 T cell responses.

The recombinant vector vaccine was also well-tolerated, but higher doses led to some adverse events such as pain and fever. By week 4 following immunization, 93.3% of vaccinees experienced positive CD4 T cell responses, and 60% experienced positive CD8 T cell responses.

"HIV-specific CD8 cell responses clear virus infected cells, and appear during the declining viremia following acute infection," explained Graham. "HIV-specific CD4 responses also peak early in infection; however this response diminishes soon after seroconversion. Maintenance of a functional HIV-specific CD4 T cell response correlates with long term non-progression of HIV disease."

Harriet L. Robinson, PhD, from Emory University and Kent J. Weinhold, PhD, from Duke University commented on the impact of these results in their accompanying editorial. "The DNA studies are a landmark for DNA-based vaccines in that they are the first to demonstrate a DNA vaccine successfully eliciting immune responses in essentially all vaccinated volunteers," they said. "The Ad5 recombinant HIV vaccine had both a higher percentage of responders and, overall, a higher magnitude of responses than the DNA vaccine."

The next step, according to Graham, is "to evaluate the combination of DNA priming and rAd5 boosting. Combining these distinct gene-delivery vaccination approaches has the potential to induce higher levels of T cell responses and a different quality of response than either approach by itself."

As Robinson and Weinhold add, the idea behind combining strategies is that "the vaccine uses DNA to prime the immune response and a replication defective recombinant adenovirus serotype 5 vector to boost responses."


'"/>

Source:Infectious Diseases Society of America


Related biology news :

1. Bevacizumab Combined With Chemotherapy Improves Progression-Free Survival for Patients With Advanced Breast Cancer
2. AIDS Public Awareness Campaign Expands Following Report Of Rapidly Progressive HIV
3. Progress on HIV/AIDS significant but insufficient
4. Progress being made in exploring potential use of stem cells to treat heart disease
5. Progress toward artificial photosynthesis?
6. Research advances quest for HIV-1 vaccine
7. A much-needed shot in the arm for HIV vaccine development
8. Discovery of key proteins shape could lead to improved bacterial pneumonia vaccine
9. Gene vaccine for Alzheimers disease shows promising results
10. Influenza vaccine uses insect cells to speed development
11. Norovirus, AIDS vaccine and Hepatitis Virus
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/5/2017)... , April 5, 2017  The Allen Institute ... Allen Cell Explorer: a one-of-a-kind portal and dynamic digital ... 3D imaging data, the first application of deep learning ... human stem cell lines and a growing suite of ... platform for these and future publicly available resources created ...
(Date:4/5/2017)... , April 4, 2017 KEY FINDINGS ... to expand at a CAGR of 25.76% during the ... is the primary factor for the growth of the ... https://www.reportbuyer.com/product/4807905/ MARKET INSIGHTS The global stem ... technology, application, and geography. The stem cell market of ...
(Date:4/3/2017)... , April 3, 2017  Data captured ... engineering platform, detected a statistically significant association ... prior to treatment and objective response of ... potential to predict whether cancer patients will ... treatment, as well as to improve both pre-infusion ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... ... October 10, 2017 , ... San Diego-based team building and cooking events company, ... today. The bold new look is part of a transformation to increase awareness, ... significant growth period. , It will also expand its service offering from its signature ...
(Date:10/10/2017)... firm Parks Associates announced today that Tom Kerber , ... Meeting , October 11 in Scottsdale, Arizona . Kerber ... smart safety and security products impact the competitive landscape. ... Parks Associates: Smart Home Devices: Main Purchase Driver ... "The residential security market has experienced continued growth, and the introduction ...
(Date:10/9/2017)... 9, 2017  BioTech Holdings announced today identification ... its ProCell stem cell therapy prevents limb loss ... Company, demonstrated that treatment with ProCell resulted in ... as compared to standard bone marrow stem cell ... in reduction of therapeutic effect.  ...
(Date:10/9/2017)... San Antonio, Texas (PRWEB) , ... ... ... a new study published on October 5, 2017, in the medical journal, ... demonstrated equivalence with the gold standard, video EEG, in detecting generalized tonic-clonic ...
Breaking Biology Technology: