Finally, an AIDS vaccine?

[jjmd3_787]

A world first: Vaccine helps prevent HIV infection

By MARILYNN MARCHIONE and MICHAEL CASEY, Associated Press Writers Marilynn Marchione And Michael Casey, Associated Press Writers
BANGKOK – For the first time, an experimental vaccine has prevented infection with the AIDS virus, a watershed event in the deadly epidemic and a surprising result. Recent failures led many scientists to think such a vaccine might never be possible.
The vaccine cut the risk of becoming infected with HIV by more than 31 percent in the world's largest AIDS vaccine trial of more than 16,000 volunteers in Thailand, researchers announced Thursday in Bangkok.
Even though the benefit is modest, "it's the first evidence that we could have a safe and effective preventive vaccine," Col. Jerome Kim said in a telephone interview. He helped lead the study for the U.S. Army, which sponsored it with the National Institute of Allergy and Infectious Diseases.
The institute's director, Dr. Anthony Fauci, warned that this is "not the end of the road," but said he was surprised and very pleased by the outcome.
"It gives me cautious optimism about the possibility of improving this result" and developing a more effective AIDS vaccine, Fauci said in a telephone interview. "This is something that we can do."
Even a marginally helpful vaccine could have a big impact. Every day, 7,500 people worldwide are newly infected with HIV; 2 million died of AIDS in 2007, the U.N. agency UNAIDS estimates.
"Today marks an historic milestone," said Mitchell Warren, executive director of the AIDS Vaccine Advocacy Coalition, an international group that has worked toward develping a vaccine.
"It will take time and resources to fully analyze and understand the data, but there is little doubt that this finding will energize and redirect the AIDS vaccine field," he said in a statement.
The Thailand Ministry of Public Health conducted the study, which used strains of HIV common in Thailand. Whether such a vaccine would work against other strains in the U.S., Africa or elsewhere in the world is unknown, scientists stressed.
The study actually tested a two-vaccine combo in a "prime-boost" approach, where the first one primes the immune system to attack HIV and the second one strengthens the response.
They are ALVAC, from Sanofi Pasteur, the vaccine division of French drugmaker Sanofi-Aventis; and AIDSVAX, originally developed by VaxGen Inc. and now held by Global Solutions for Infectious Diseases, a nonprofit founded by some former VaxGen employees.
ALVAC uses canarypox, a bird virus altered so it can't cause human disease, to ferry synthetic versions of three HIV genes into the body. AIDSVAX contains a genetically engineered version of a protein on HIV's surface. The vaccines are not made from whole virus — dead or alive — and cannot cause HIV.
Neither vaccine in the study prevented HIV infection when tested individually in earlier trials, and dozens of scientists had called the new one futile when it began in 2003.
"I really didn't have high hopes at all that we would see a positive result," Fauci confessed.
The results proved the skeptics wrong.
"The combination is stronger than each of the individual members," said the Army's Kim.
The study tested the combo in HIV-negative Thai men and women ages 18 to 30 at average risk of becoming infected. Half received four "priming" doses of ALVAC and two "boost" doses of AIDSVAX over six months. The others received dummy shots. No one knew who got what until the study ended.
All were given condoms, counseling and treatment for any ***ually transmitted infections, and were tested every six months for HIV. Any who became infected were given free treatment with antiviral medicines.
Participants were followed for three years after vaccination ended.
Results: New infections occurred in 51 of the 8,197 given vaccine and in 74 of the 8,198 who received dummy shots. That worked out to a 31 percent lower risk of infection for the vaccine group.
The vaccine had no effect on levels of HIV in the blood of those who did become infected. That had been another goal of the study — seeing whether the vaccine could limit damage to the immune system and help keep infected people from developing full-blown AIDS.
That result is "one of the most important and intriguing findings of this trial," Fauci said. It suggests that the signs scientists have been using to gauge whether a vaccine was actually giving protection may not be valid.
"It is conceivable that we haven't even identified yet" what really shows immunity, which is both "important and humbling" after decades of vaccine research, Fauci said.
Details of the $105 million study will be given at a vaccine conference in Paris in October.
This is the third big vaccine trial since 1983, when HIV was identified as the cause of AIDS. In 2007, Merck & Co. stopped a study of its experimental vaccine after seeing it did not prevent HIV infection. Later analysis suggested the vaccine might even raise the risk of infection in certain men. The vaccine itself did not cause infection.
In 2003, AIDSVAX flunked two large trials — the first late-stage tests of any AIDS vaccine at the time.
It is unclear whether vaccine makers will seek to license the two-vaccine combo in Thailand. Before the trial began, the U.S. Food and Drug Administration said other studies would be needed before the vaccine could be considered for U.S. licensing.
Also unclear is whether Thai volunteers who received dummy shots will now be offered the vaccine. Researchers had said they would do so if the vaccine showed clear benefit — defined as reducing the risk of infection by at least 50 percent.
Those issues, plus how to proceed with future studies, will be discussed among the governments, study sponsors and companies involved in the trial, Kim said. Scientists want to know how long will protection last, whether booster shots will be needed, and whether the vaccine helps prevent infection in gay men and injection drug users, since it was tested mostly in hetero***uals in the Thai trial.
The study was done in Thailand because U.S. Army scientists did pivotal research in that country when the AIDS epidemic emerged there, isolating virus strains and providing genetic information on them to vaccine makers. The Thai government also strongly supported the idea of doing the study.

I'm just curious . . . how does it feel to be a volunteer test subject in this study?

[ghosthunter]

I'm just curious . . . how does it feel to be a volunteer test subject in this study?

You get to do lots of bareback testing paid by the testing clinic. :attack:

[uls]

year 2006, 16,402 volunteers

half were given vaccines and half were given placebos

everyone got regular tests for the AIDS virus for 3 years

those who got placebos, 74 became infected

those who got the vaccines, 51 became infected

small difference but they consider it statistically significant

[praetor91313]

Parang malabo a.

Dun sa binigyan, how promiscuous were they? Did they practice unsafe *** all the time? What were their overall risks for getting AIDS?

Sobrang dami pang variables... di ba dapat for a study to be valid, dapat pare-pareho ang exposure ng test group at control group?

Also, di ba may nakita din silang AIDS receptor sa cells natin? Last I heard, they were attributing the infection rate to this phenomenon. Ito daw ang rason kung bakit yung iba minsan lang nakipagtalik sa taong may AIDS nahawa kaagad at yung iba, multiple na ang exposures, di pa rin nahahawa...

Remember Sarah Jane, nagpa-test yung mga kalalakihan ng buong street nila noon dahil puro nakatalik daw nya, wala naman nahawa? Si Magic Johnson, ang tagal na nila nagsasama ng wife nya but di rin nahawa?

Did they also take this into consideration? Di ba dapat equal din ang distribution ng may marami ang konting AIDS receptors sa cells?

Lastly, I always thought there would never really be a vaccine for AIDS because the virus keeps on mutating and everytime they produce a vaccine for one variant, may bago na naman?

AND, I also thought that there would never be a cure for AIDS dahil ang virus na ito ay sumasakay sa DNA strand ng cells natin para magreproduce... so if you were infected, it's essentially incorporated in your DNA at para matanggal mo kailang perfected na natin ang genetic engineering dahil kailangan hanapin mo lahat ng virus na kumabit sa strand tpaos ayusin mo ulit yung DNA strand sa dati nyang combination... And if we were able to do that, then everything's possible-- kaya na din natin hanapin ang strand na trigger ng hypertension, cancer, etc... at ire-arrange natin para di na ma-activate, which we know is virtually impossible for now or even for the next ten years...

[niky]

Sucks to be one of the statistically significant infectees.

A 31% prevention rate isn't a vaccine... and that isn't 31%... it's more like this:

The placebo protected 99% of the test subjects from AIDS.

The vaccine protected 99.3%.

Thus... the most cost-effective way of treating the AIDS epidemic? Give everyone sugar pills.

[cktlcmd]

small difference but they consider it statistically significant

Just as Sir uls said: STATISTICALLY SIGNIFICANT! It does not matter what the actual numbers are.

Parang malabo a.

Dun sa binigyan, how promiscuous were they? Did they practice unsafe *** all the time? What were their overall risks for getting AIDS?

Sobrang dami pang variables... di ba dapat for a study to be valid, dapat pare-pareho ang exposure ng test group at control group?

Also, di ba may nakita din silang AIDS receptor sa cells natin? Last I heard, they were attributing the infection rate to this phenomenon. Ito daw ang rason kung bakit yung iba minsan lang nakipagtalik sa taong may AIDS nahawa kaagad at yung iba, multiple na ang exposures, di pa rin nahahawa...

Remember Sarah Jane, nagpa-test yung mga kalalakihan ng buong street nila noon dahil puro nakatalik daw nya, wala naman nahawa? Si Magic Johnson, ang tagal na nila nagsasama ng wife nya but di rin nahawa?

Did they also take this into consideration? Di ba dapat equal din ang distribution ng may marami ang konting AIDS receptors sa cells?

Lastly, I always thought there would never really be a vaccine for AIDS because the virus keeps on mutating and everytime they produce a vaccine for one variant, may bago na naman?

AND, I also thought that there would never be a cure for AIDS dahil ang virus na ito ay sumasakay sa DNA strand ng cells natin para magreproduce... so if you were infected, it's essentially incorporated in your DNA at para matanggal mo kailang perfected na natin ang genetic engineering dahil kailangan hanapin mo lahat ng virus na kumabit sa strand tpaos ayusin mo ulit yung DNA strand sa dati nyang combination... And if we were able to do that, then everything's possible-- kaya na din natin hanapin ang strand na trigger ng hypertension, cancer, etc... at ire-arrange natin para di na ma-activate, which we know is virtually impossible for now or even for the next ten years...

You do raise important questions about the variables, but without a proper copy of the protocol they followed during the screening and follow-ups, all we can do is accept it as it is.

One big note though I would like to make. HIV, is a retro virus, it is an RNA virus. They might think it is a DNA virus because of your last pharagraph.

[niky]

Just as Sir uls said: STATISTICALLY SIGNIFICANT! It does not matter what the actual numbers are.

Errh... ULS was pointing out that the difference is small, but the researchers consider it statistically significant. He doesn't say whether or not he considers it statistically significant.

The whole point of a vaccine is to prevent infection. If the infection rate of a population goes down by just 0.3 percent, that's too small a difference to consider the vaccine a success. Not just yet.

[uls]

the results of previous AIDS vaccine trials were so bad... (some participants even became more susceptible to infection)

that this one, with only 30% effectiveness, made the researchers jump for joy

[jjmd3_787]

With the HIV vaccine's success rate by which these scientists are currently claiming (and enjoying), I guess monogamy is still the best policy.

[praetor91313]

One big note though I would like to make. HIV, is a retro virus, it is an RNA virus. They might think it is a DNA virus because of your last pharagraph.

Uhm... sorry po, medyo OT na kami, pero I've re-read my post and I can't find the part where I said it was a DNA virus... I just said it gets incorporated into our DNA. I don't think I classsified it as to what type of virus it is.

Anyways, just to set things straight, as sir cktlcmd stated, the HIV/AIDS virus is an RNA virus-- for simplicity's sake, think of this as half of a DNA (which are the building blocks of life).

Pag pumasok na sa katawan mo ang virus na to, kakabit sya sa cell mo (specifically the CD4 molecule) via its GP120 protein. Once this happens, parang transformers, it goes into a conformational change and binds to the co-receptors CCR5 and/or CXCR4. Ito yung sinabiko sa taas na depende sa dami ng mga ito sa katawan natin, mas mataas ang affinity ng virus sa cells mo and therefore almost translates to how high your chances of getting infected are.

So nakadikit na yung HIV/AIDS virus sa cell. Next, the virus becomes uncoated, tatanggalin nya yung coating nya at papasok yung pinakalaman nya sa loob ng cell mo. Ang masama pa nito, may dala syang reverse transcriptase enzye-- ito ang magbibgay sa HIV/AIDS virus (RNA virus) ng kalahati nya therefore making it a double-stranded DNA virus na. Naku po... malaking problema na yan.

Dahil double-stranded na sya ngayon, papasok na sya sa nucleus ng cells mo at ilalabas nya ang isa pa nyang enzyme, ang integrase. Ito ang maghihiwalay sa original na DNA mo at magpapasok sa dsDNA ng HIVsa loob nya.

Ang masama nito, pag nag-encode ulit ang katawan mo ng bagong DNA, dahil nakasingit doon ang virus, pati yung code nya makokopya kaya dadami nang dadami yung virus!! We call it a provirus at this point.

Kakabit ito sa inner portion ng cell mo, sa plasma membrane at kukuha sa ng part nito para gumawa ng sarili nyang lining ulit para may balat na naman sya. Doon na sya lalabas at iikot-ikot lang sa katawan mo para kumalat ulit.

Back to our topic: naalala nyo yung tungkol sa pagkabit sa mga receptors na sinabi ko sa taas at yung tungkol sa integrase? Yan ang tinatarget ng mga iniimbento nila ngayon na mga gamot.

Kahit yung part kung saan nagiging double-stranded DNA ang RNA virus na ito, ang ginagamit nyang enzyme ay ang reverse transcriptase. Gumagawa din sila ng gamot para labanan ito.

Let's hope after all these years of research, may full-proof na na makitang gamot o vaccine man lang, but as I've stated before, yun pa lang pagbilis ng mutation ng virus na to sobrang pinapahirapan na nya ang mga researchers. What's more, everytime they reach a breakthrough, mas maraming problems ang lumilitaw.

I agree with everyone's viewpoint here that the best thing to do here is to abstinence pa rin talaga.

Re: infection through donated blood products, kahit na maganda na ang screening procedures natin, may pakonti-konti pa ring lumulusot talaga e.