Microbicide & HIV

Finding a protection from HIV is needed by people. WHO (World Health Organization) says that microbicide can protect people against HIV and other sexual transmitted diseases. Microbide itself are compounds. The compounds are used inside of the vagina or rectum. The compounds which formed in gel, cream, films, or suppositories are able to decrease the risk of the disease’s transmission.

Using Microbicides become important for people to prevent the infection of STD especially HIV. It becomes the other way for the method in preventing HIV, instead of using condom. The microbicide will help women to involve in the prevention. The prevention will be not only depended on men. Women can take control to prevent them to be infected.

Microbicide & Safe Sex (8)

HIV/Aids
Persons initially infected with HIV may develop an "acute retroviral syndrome" characterized by fever, lymph node enlargement, and flu-like symptoms. If symptoms are present, they clear spontaneously, but all infected persons, both with and without symptoms, remain infected and infectious to others indefinitely. The incubation period is highly variable, averaging about a decade, but ranging from a few months or years to possibly longer than two decades. When sufficient damage to the immune system has been sustained, measured either by laboratory cell counts of the Thelper cells or by onset of opportunistic infections, the patient is said to have AIDS. Common manifestations of HIV infection include tiredness, lymph node enlargement, fever, weight loss, and yeast infections of the mouth and vagina.

HIV infection is diagnosed by laboratory detection of evidence of infection, usually identification of HIV-specific antibodies in a blood, oral fluid, or urine specimen. AIDS can be diagnosed in HIV-infected persons in several ways, based on either laboratory evidence of immunodeficiency (lowered levels of CD4+ cells), or clinically by onset of any one or more of a specific list of opportunistic diseases. Opportunistic diseases are those that occur only, or most severely, in patients whose immune systems are impaired. The most common opportunistic diseases in AIDS patients are Pneumocystis carinii pneumonia, Kaposi's sarcoma, toxoplasmosis of the brain, tuberculosis and other mycobacterial infections, and severe herpes, cytomegalo virus, and yeast infections.

How the AIDS Virus Works?
The AIDS virus weakens the immune system (“immune deficiency”), allowing other infections to ravage the body. These infections are called “opportunistic” because they take advantage of the opportunity to live where the body’s immune system would normally destroy them. It’s when these opportunistic infections strike that the person is said to have AIDS.

Microbicide & Safe Sex (2)

STD Risk of unsafe sex
Vaginal or anal intercourse without a condom and/or microbicide — high risk for passing:
- chancroid
- chlamydia
- cytomegalovirus (CMV)
- genital warts
- gonorrhea
- hepatitis B
- herpes
- human immunodeficiency virus (HIV)
- human papilloma virus (HPV)
- pelvic inflammatory disease (PID)
- pubic lice
- scabies
- syphilis
- trichomoniasis

Oral sex without a condom — High risk for passing:
- CMV
- gonorrhea
- hepatitis B
- herpes
- syphilis

Microbicide & Safe Sex (1)

In this first decade of the 21st century the various risks connected with having sex have (alas) increased.
The figures for HIV, chlamydia and gonorrhoea are all going up. This is almost entirely because so many people – whether they're heterosexuals or homosexuals or 'bi' – don't practise safe sex.

One way to have safer sex is to only have one partner who has no sexually transmitted infections and no other partners than you.

But, this isn't always the safest kind of safer sex. That's because most people don't know when they have infections. They are very likely to pass them on without knowing it.

Another other reason is that some people aren't as honest as they should be. In fact, about 1 out of 3 people will say they don't have an infection when they know they do, just to have sex. So most of us have to find other ways to practice safer sex.

Another way to practice safer sex is to only have sex play that has no risk — or a lower risk — of passing STDs. This means no vaginal or anal intercourse. Many of us find that great sex is about a lot more than a penis going in a vagina or anus. It is about exploring the many other ways you and your partner can turn each other on. Not only is it a way to discover new sexual pleasures, it's also safer.

Safe Sex:
- Reduces our risk of getting a sexually transmitted disease (STD)
- Using condoms and/or microbicide makes vaginal or anal intercourse safer sex
Although condoms provide the best form of protection for people who are sexually active, using a microbicide will be much safer than nothing for women for whom condom use is unlikely or impossible.

For some women and men, the contraceptive effect of condoms is a major deterrent to use; developing both contraceptive and non-contraceptive microbicides is important. Providers can counsel patients on the use of microbicides in conjunction with condoms for added protection, and as a "backup" method when condom use cannot or does not occur.

Microbicide Delivery system

The past decade has seen several effective anti-HIV-1 agent discoveries, yet microbicides continue to disappoint clinically. Our review expounds the view that unsatisfactory microbicide failures may be a result of inefficient delivery systems employed.

Microbicide delivery devices will be critical in ensuring safe and effective use of microbicide products. The device impacts the product’s overall safety (relationship with product purity and stability, avoidance of local trauma associated with insertion or use), efficacy (consistent delivery of the required amount of product in the intended location), and acceptability (comfort, ease of use, disposability).

Several novel microbicide delivery methods to help reduce cost, ensure microbicide efficacy, and increase user acceptability. Methods include:
• Diaphragm:  This combination of barrier method and microbicide could enable prevention of both pregnancy and disease. Two studies were recently completed. One study assessed gel retention and distribution in the vagina comparing Diaphragm single-sided and double-sided gel delivery to a
vaginal applicator. The second study used the same three gel application modes and evaluated couples’ use acceptability.
• Paper applicator with dosage stop: This user-filled applicator is low cost, easily disposed of, and prevents over-filling, making it an important option for microbicide gel delivery in low-resource settings.
• Rectal applicator: This applicator has been designed specifically for the rectal delivery of microbicide products.

Intravaginal targeting of HIV-1 increases the chances of microbicide success, wherein vaginal micro environmental factors including pH should be maintained at HIV-1 prohibitive acidic levels simultaneously to ward off other sexually transmitted diseases, which compromise vaginal epithelial barrier properties.

Furthermore, choice of receptors to target both on HIV-1 and on target cells is vital in deterring transmission. Appropriate modeling of virus–target cell interactions as well as targeting early stages of the HIV-1 infection accompanied by computation and delivery of appropriate microbicide quantities could revolutionize microbicide research, ultimately delivering a female-controlled HIV-1 prevention modality appropriately.
(Qualitative and quantitative intravaginal targeting: Key to anti-HIV-1 microbicide delivery from test tube to In Vivo success; Viness Pillay,*, Felix Mashingaidze, Yahya E. Choonara, Lisa C. Du Toit, Eckhart Buchmann, Vinesh Maharaj, Valence M. K. Ndesendo, Pradeep Kumar)

Microbicide & Herpes (2)

Genital herpes is one of the most prevalent sexually transmitted infections worldwide and is the most common cause of genital ulcers. Despite increased public awareness and the initiation of efforts to prevent transmission, the prevalence of herpes simplex virus (HSV) type 2 continues to increase.

What makes HSV so difficult to control is that most sexual and perinatal transmission occurs during unrecognized or asymptomatic shedding. The impact of genital herpes as a public health threat is amplified because of its epidemiological synergy with HIV/AIDS. Thus, there is an urgent need for novel prophylactic methods, such as topical microbicides designed for genital application, to prevent both HSV and HIV transmission.

In summary, genital herpes is a critical global health priority because of its devastating impact on young adults and infants and its association with the HIV/AIDS epidemic. Topical microbicides that block transmission at the mucosal surface may provide a realistic method of intervention for worldwide distribution. Currently, there are several candidate drugs being advanced to clinical trials that block both HSV and HIV infection by inhibiting binding and entry in vitro.

Whether blockade of entry will be sufficient to prevent sexual transmission or whether a combination strategy targeting multiple steps in the viral life cycle will be required is not yet known. Importantly, before embarking on large-scale clinical trials, more extensive evaluation of candidate microbicides, including assessment of the impact on innate defences, is warranted. Assessment of the safety and mucosal response to microbicides should be accrued from several different models including cell and organ cultures, animal models and, most importantly, pilot clinical studies.

((Excerpt of)Topical microbicides for the prevention of genital herpes infection: Marla J. Keller, Ana Tuyama, Maria Josefina Carlucci and Betsy C. Herold)

A topical microbicide that silences two genes can safely protect against genital herpes infection for as long as one week, according to a joint study by researchers at the Albert Einstein College of Medicine of Yeshiva University and Harvard Medical School.

Microbicide & Herpes (1)

Excitement here over a microbicide that protects women against HIV grew when researchers reported that it also protects against herpes simplex virus-2 (HSV-2) infection.
The gel is not a contraceptive, but a microbicide. Microbicidal gels or creams are inserted into the vagina solely to prevent the spread of HIV and other sexually transmitted diseases. There are currently no such products on the market. Women who have herpes are at increased risk of contracting HIV, so diminishing the risk of getting herpes also diminishes the risk of HIV infection.
In a randomized controlled trial, the vaginal gel reduced women's risk of HIV infection by 39% compared with placebo, according to researchers.


A 2010 clinical trial found that microbicides -- vaginal gel spiked with antiretrovirals -- cut HIV transmission during sex by 39 percent. But researchers also found that microbicides reduced a woman's risk of herpes by a whopping 51 percent.

(Excerpts of) A Summary of Preclinical Topical Microbicide Vaginal Safety and Chlamydial Efficacy Evaluations in a Pigtailed Macaque Model

Patton, Dorothy L. PhD; Cosgrove Sweeney, Yvonne T. BA; Paul, Kathleen J. MPH

Background:
The development of topical microbicides represents a new and exciting field in the prevention of sexually transmitted diseases, and it is especially important that candidate products undergo rigorous preclinical safety and efficacy testing before advancing to clinical trials.

Methods:
We have developed a standardized protocol for preclinical vaginal safety and efficacy assessment of topical microbicide candidates in a nonhuman primate model. Over 7 years of funding under an NIH contract, we evaluated a total of 28 test compounds for vaginal safety (via colposcopy, vaginal pH, and microflora) and 9 compounds for efficacy against cervical chlamydial infection. We also outline the specific criteria used to determine which products should move into efficacy trials and which should be recommended for reformulation to the manufacturer.

Results:
Overall, we noted acceptable safety profiles for 24 of 28 candidate products. Common findings included a transient decrease in vaginal pH, petechiae, and mild erythema. Four products were associated with significant adverse colposcopic findings including blisters, epithelial abrasions, and friability; all 4 products were successfully reformulated and showed acceptable safety profiles at lower concentrations. No products showed complete protection against cervical chlamydial infection.

Conclusions:
The macaque preclinical safety and efficacy model is critical to maintaining the pace of topical microbicide development, which could ultimately offer a significant opportunity for intervention in the global HIV/AIDS epidemic.

Overall safety profiles were acceptable in 24 products. Microbiologic findings common to most products included stable populations of H2O2-producing lactobacilli and Viridans streptococci and transient decreases in anaerobic Gram-negative rods.

Microbicide Safety

The development of topical microbicides represents a new and exciting field in the prevention of sexually transmitted diseases, and it is especially important that candidate products undergo rigorous preclinical safety and efficacy testing before advancing to clinical trials.


The physico-chemical and biological properties of active pharmaceutical ingredients (APIs) and their formulations are the foundation of safe, efficacious and acceptable microbicides. Hence, the initial selection of the API and its primary formulation is crucial. Certain undesirable properties of an API can be compensated or masked by an appropriate formulation. However, there is a risk in proceeding with inadequate APIs or formulations, as they may fail later in development, costing more time and money. 

It is important to have a set of criteria that inform Go/No Go decisions prior to entering in clinical trials. This set of criteria is based on API and formulation parameters derived from a comprehensive evaluation of their in vitro P/C properties, drug release rates, specific activity, and cell and tissue toxicity, which in turn represent the base for animal studies focused on organ toxicity/safety, pharmacokinetics (PK), and pharmacodynamics (PD) and efficacy.

A solid preclinical foundation will help navigate clinical testing successfully, ultimately leading to a safe and effective microbicide. In addition to the more classical IND-enabling studies, new models, assays and biomarkers have been developed and adapted to the evaluation of genital and rectal microbicides.

Experience with previous microbicide candidates has led to the inclusion of assays evaluating the impact of genital environmental factors such as low pH, seminal plasma, CV secretions and microflora on microbicide safety and efficacy. Microbicide-induced inflammatory mediators and alteration of innate immunity have also been recently incorporated to the standard testing.

Looking for a Few Good Microbicides Candidates

Until recently, microbicide discovery was a by-product of the search for anti-HIV drugs. Early in the search for microbicides, for example, attention focused on detergents because of their ability to disrupt HIV’s coat. Most such easily testable candidates, however, failed as microbicides. Now that scientists know more about HIV’s life cycle,
they are beginning to identify multiple points at which the virus could be stopped.

Ideally, a microbicide should be:
• Colorless and odorless
• Inexpensive to manufacture and purchase
• Safe to use more than once a day and for long periods of time
• Effective against multiple STDs, including HIV/AIDS
• Fast-acting, long-lasting, and non-irritating
• Undetectable to either partner
• Available in contraceptive and non-contraceptive forms
• Available without a prescription

In theory, creating an effective topical microbicide should be easy. Simply identify chemicals that kill disease-causing organisms, blend the chemicals with an inert gel or foam, and place it in the vagina. Experience, however, has shown that the simple approach may not work.

The Research Pipeline 
Like a new drug or vaccine, topical microbicide development will follow a pathway—the research pipeline—from basic research to commercial production. The key points along the pipeline are basic research, product formulation and preclinical testing, and clinical testing.

Microbicide actions

Microbicides can act in various ways. Microbicides can be nonspecific, moderately specific or highly (exclusively) specific to HIV. The nonspecific and moderately specific agents are often active against a variety of sexually transmitted microorganisms (e.g., chlamydia and herpesvirus) and may have a contraceptive effect. The HIV-specific agents interact directly with one or several steps of the infection or replication cycle of HIV.

Nonspecific microbicides
The nonspecific microbicides consist of buffering agents and of detergents or surfactants that include nonionic, anionic or cationic compounds. The detergents destroy the viral envelope by solubilizing membrane proteins. However, this nonspecific mechanism of action may also disrupt the cell membranes of the vaginal and cervical epithelium and cause erosions and lesions, leading to an increased risk of HIV infection.

Moderately specific microbicides
Moderately specific microbicides mainly comprise  macromolecular linear anionic polymers. Linear polyanions are active against HIV, HSV and in some cases demonstrate inhibitory activity against human papillomavirus (HPV), Neisseria gonorrhoeae and Chlamydia trachomatis. They block viral entry into cells through electrostatic interactions with the viral envelope proteins and, in some cases, host cell receptors. The lack of potency of linear polyanions for HIV and the ability of semen to further abrogate anti-HIV activity, may in part explain the lack of in vivo efficacy of these microbicides. In addition, adherence to product use and transmission via anal receptive sex, which would not be prevented by a vaginally applied microbicide, are other considerations.

Highly specific anti-HIV agents
HIV-specific microbicides should preferentially block the viral infection cycle before the viral genome gets
incorporated in the target cells as proviral DNA.

Targeting viral entry seems the most promising method, preventing virus particles from entering its susceptible cells and, as shown or expected for most entry inhibitors, also preventing transmission of the virus from virus-infected cells to uninfected cells or transmission of dendritic cell-captured virus to lymphoid cells, or both.

The Future of Microbicide

Topical microbicides are a broad class of agents designed to block or kill infectious microorganisms directly at the site of transmission. With the AIDS pandemic continuing its unrelenting global march (40 million current infections, 14,000 new infections per day) driven largely by sexual transmission, microbicides have moved steadily toward the front line of preventative strategies.

Indeed, many candidate anti-HIV microbicides are currently under development, with several already in clinical trials. A battery of promising protein-based HIV inhibitors can potentially be developed, but they face serious challenges of high production costs and instability during transport and storage.

In a recent issue of PNAS, Rao et al. presented an intriguing version of a “live microbicide” approach whereby a commensal bacterium is engineered to secrete a potent anti-HIV peptide. When administered orally or as a rectal suppository, the bacteria would colonize the gut mucosa and secrete the peptide in situ, thereby providing protection in advance of exposure hopefully for days, weeks, or even months. This delivery mode would be highly advantageous over others requiring repeated topical application before each act of intercourse; also, the engineered bacteria would be relatively simple and inexpensive to manufacture, transport, and store.(An anti-HIV microbicide comes alive; Laurel A. Lagenaur and Edward A. Berger)

An antiretroviral microbicide gel can cut HIV infection in women by more than 50% if used consistently.
Most of the products tested previously as microbicides were either sulphated polysaccharides — which are intended to stop the virus from entering cells — or agents that prevent infection by killing either the virus or cells that carry it.

(Excerpt of) Potential Impact of Vaginal Microbicides on HIV Risk Among Women with Primary Heterosexual Partners

James M. McMahon, PhD, Associate Professor, Kathleen M. Morrow, PhD, Associate Professor, Margaret Weeks, PhD, Professor, Dianne Morrison-Beedy, PhD, RN, FNAP, WHAP, Professor and Dean, and Amanda Coyle, APRN, Senior Associate

Over the past 2 decades women have increasingly shouldered the burden of the global HIV pandemic (Joint United Nations Programme on HIV/AIDS [UNAIDS], 2004), with the majority of infected women acquiring HIV through sexual contact with a primary male partner (O’Leary, 2000). These trends are the result of multiple factors. Women may be biologically more susceptible to heterosexual transmission of HIV than men, especially via receptive anal intercourse (Boily et al., 2009; Mastro & Kitayaporn, 1998; Padian, Shiboski, & Jewell, 1991). 

In addition, gender-based social inequalities limit women’s options with regard to protective sexual behavior (Higgins, Hoffman, & Dworkin, 2010; Quinn & Overbaugh, 2005; Remien, Halkitis, O’Leary, Wolitski, & Gomez, 2005). Latex condoms, currently the only effective form of barrier protection against HIV, are under the control of men, who often are unwilling to use them, especially in the context of primary relationships (Conley & Collins, 2005).

Vaginal microbicides represent a female-initiated form of barrier and/or chemical protection that can potentially empower women with a means of self-protection. Vaginal microbicides are self-administered chemical compounds, most commonly in the form of a gel, that women can apply intravaginally prior to sexual intercourse to prevent or reduce HIV transmission. Modeling studies indicate that even a partially effective microbicide could have a major impact on the global HIV pandemic (Watts, 2002). 

Microbicides and women

Microbicides are substances capable of reducing the transmission of HIV and other sexually transmitted pathogens when applied vaginally.Evidence from many settings strongly suggests that many women will find microbicides easier to use than condoms and that they can be used when condom use is not possible. This has raised the concern that women might abandon condoms in favour of microbicides. Indeed, the fear of 'condom migration' has been a major barrier to the widespread endorsement of microbicides as a potential method of HIV prevention.

Despite such high HIV-efficacy, there is substantial evidence that in many settings levels of consistent condom use is low, especially within primary partnerships. Studies show that even after directed intervention, the percentage of couples that achieve consistent condom use seldom exceeds 20-30%, except where individuals know that one partner is HIV infected. Success in increasing the consistency of condom use has been greatest among sex workers and other vulnerable groups, but even here, many sex workers do not use condoms consistently with their non-commercial, primary partners.

Even when condoms are used consistently they may be used incorrectly. The immense gap between the numbers requiring protection and those using condoms consistently and correctly could potentially be filled by microbicides.

With AIDS vaccine efforts at an impasse, microbicides -- virus-blocking gels inserted into the vagina before sexual intercourse -- have risen from their own string of setbacks to once again offer hope of preventing HIV infections, at least in women.

Identifying a microbicide that works even partially could have a huge effect. Almost half of the more than 33 million people living with HIV worldwide are women; in sub-Saharan Africa, the figure is 60%.Abstinence and condoms have been the only proven ways to prevent or reduce the spread of HIV among adults. Circumcision lowers the risk for men, and already-existing AIDS drugs are used prophylactically to reduce mother-to-child transmission during birth or breast-feeding.

(The Excerpt of) Potential Impact of Vaginal Microbicides on HIV Risk Among Women with Primary Heterosexual Partners

James M. McMahon, PhD, Associate Professor, Kathleen M. Morrow, PhD, Associate Professor, Margaret Weeks, PhD, Professor, Dianne Morrison-Beedy, PhD, RN, FNAP, WHAP, Professor and Dean, and Amanda Coyle, APRN, Senior Associate

Over the past 2 decades women have increasingly shouldered the burden of the global HIV pandemic (Joint United Nations Programme on HIV/AIDS [UNAIDS], 2004), with the majority of infected women acquiring HIV through sexual contact with a primary male partner (O’Leary, 2000). These trends are the result of multiple factors. Women may be biologically more susceptible to heterosexual transmission of HIV than men, especially via receptive anal intercourse (Boily et al., 2009; Mastro & Kitayaporn, 1998; Padian, Shiboski, & Jewell, 1991). 

In addition, gender-based social inequalities limit women’s options with regard to protective sexual behavior (Higgins, Hoffman, & Dworkin, 2010; Quinn & Overbaugh, 2005; Remien, Halkitis, O’Leary, Wolitski, & Gomez, 2005). Latex condoms, currently the only effective form of barrier protection against HIV, are under the control of men, who often are unwilling to use them, especially in the context of primary relationships (Conley & Collins, 2005).

Vaginal microbicides represent a female-initiated form of barrier and/or chemical protection that can potentially empower women with a means of self-protection. Vaginal microbicides are self-administered chemical compounds, most commonly in the form of a gel, that women can apply intravaginally prior to sexual intercourse to prevent or reduce HIV transmission. Modeling studies indicate that even a partially effective microbicide could have a major impact on the global HIV pandemic (Watts, 2002). 

While it is anticipated that the first generation of vaginalmicrobicides will be less effective at preventing HIV than latex condoms, the enormous potential of this new technology lies in its enhanced acceptability and usability by women. As our experience with the female condom has demonstrated, the importance of the acceptability of any new HIV prevention technology cannot be overstated (Kaler, 2004). It is therefore critically important that the public health sector in the United States prepare for the introduction of commercially available vaginal microbicides (Van de Wijgert & Coggins, 2002). While many American women have expressed a keen interest in vaginal microbicides (Darroch & Frost, 1999), the issues surrounding their acceptability and preference in relation to condom use are complex and have not received adequate attention. One complexity involves the potential reduction of condom use that might result from the introduction and adoption of microbicides.

Qualities a Microbicide Should Have

A Microbicide should:

-applicable several hours prior to intercourse
-not messy or "leaky"
-able to be applied easily and evenly around the vagina as well as cervix
-long-acting
-look, smell and taste fine
-able to avoid infection with no disrupting or irritating the delicate tissues
-bioadhesive (able to develop protective barrier against STD pathogens)
-protective against a variety of STDs
-acid-buffering (maintains regular acidity [pH] of vagina in presence of sperm)
-protective of natural vaginal environment ("friendly flora"), possibly even improving natural vaginal defense mechanisms

Some of the Microbicide's ingredients

These are some of the microbicide's ingredients:

Benzalkonium Chloride (Bzk)
Benzalkonium chloride, also known as alkyldimethylbenzylammonium chloride and ADBAC, is a mixture of alkylbenzyldimethylammonium chlorides of various even-numbered alkyl chain lengths. This product is a nitrogenous cationic surface-acting agent belonging to the quaternary ammonium group. It has three main categories of use; as a biocide, a cationic surfactant and phase transfer agent in the chemical industry.

BZK demonstrates potent in vitro activity against the majority of microorganisms causing sexually transmitted infectious diseases, including those acting as major genital cofactors of HIV transmission and associated with high morbidity or mortality. (In vitro inactivation of Chlamydia trachomatis and of a panel of DNA (HSV-2, CMV, adenovirus, BK virus) and RNA (RSV, enterovirus) viruses by the spermicide benzalkonium chloride
Laurent B-leca,b,*,  Carol Tevi-Benissana,  Anne Bianchic,  Sylvie Cotignya, Maria Beumont-Mauvielc,  Ali Si-Mohameda and  Jean-Elie Malkinc)

Xylitol
Xylitol is an organic compound with the formula (CHOH)3(CH2OH)2.Xylitol has no known toxicity in humans.

Xylitol is a sugar alcohol sweetener used as a naturally occurring sugar substitute. It is found in the fibers of many fruits and vegetables, and can be extracted from various berries, oats, and mushrooms, as well as fibrous material such as corn husks and sugar cane bagasse. Xylitol is roughly as sweet as sucrose with only two-thirds the food energy.

Microbicide Q & A (3)

How would an HIV microbicide function?
An HIV microbicide could work in 5 different ways:
- Eliminating or inactivating pathogens.
A microbicide could inhibit HIV infection by breaking down the surface of the virus or pathogen.
- Create physical barriers. Gels or creams could offer a physical barrier between pathogens or viruses, and susceptible cells in the epithelium (cell wall) of the vagina or rectum.
- Strengthening the body's natural protection.
The body has numerous naturally sourced defense system that a microbicide might be able to supplement or enhance. For example, lactobacillus is a naturally occurring, "good" bacteria that helps protect the vagina by keeping its acidic environment. This natural acidity helps foster an inhospitable environment for a lot of pathogens, including HIV. A microbicide that supports the lactobacilli in carrying out this function might inhibit infection by HIV or STDs.
- Inhibiting viral entry.
A microbicide could inhibit viral or bacterial infection by interfering with the binding of viral proteins to cellular receptors. For example, infection with the HIV virus happens through binding of gp120 (on the outside of the virus) to receptors on a cell's membrane. A potential microbicide might interrupt this process by binding to receptors ahead of time, thus blocking the sites and preventing HIV attachment to the cell.
- Suppressing viral replication. Designed as gels or creams, anti-HIV medications that are already FDA-approved and available might be able to reduce replication of HIV in the vagina or rectum during sexual intercourse.

Microbicide Q & A (1)

What is a microbicide?
A microbicide is a compound that eliminates micro-organisms.

What does a microbicide do?
Topical microbicides, applied to lining of body cavities, work as chemical barriers to avoid the spread of Sexually Transmitted Diseases (STDs).
An HIV microbicide provides the potential for a protection choice that both women and men could effortlessly control, with or without the consent or knowledge of their sexual partner.

What forms can a microbicide come in?
A microbicide could be produced in various forms including gels, creams, suppositories, films, or in combination with a sexual lubricant.

Will different HIV microbicides be necessary for vaginal and rectal use?
Probably.
Different microbicides will be necessary for the vagina and for the rectum because of differences in their physical structure and properties.
An effective rectal microbicide must take into consideration that HIV is more easily transmitted during anal rather than vaginal intercourse.

Will a microbicide cure AIDS?
No, a microbicide is not a remedy for those already infected with HIV.
Instead, it would be an HIV prevention option, impeding (or halting) the transmission of HIV.

Microbicides benefits

- Will provide women an easy way to minimize their personal risk of infection when they cannot insist on   condom use.
- May provide bi-directional protection for men sex with partners who are HIV positive or have STIs.
- Helps protect the wellness of children by helping to lower their parents' risk of infection.Prevent from HIV and STIs while still allowing you to conceive a child.
- Help protect your future children from being born with HIV and/or other STIs.
- Provide you with extra resources for making safe, informed reproductive choices.
- Offer protection against both unwanted pregnancy and diseases.
- Offer a contraceptive alternative that is non-hormonal, non-irritating, and will not interfere with intimate contact.
- Be usable with condoms or hormonal contraceptives for back-up protection.
- Provide contraceptive safety and minimize risk of infection when condoms are not being used.
- Enable you to enjoy sex with less fear of becoming infected.
- Provide lubrication thereby enhancing sexual pleasure and enjoyment.
- Be applied before sex to avoid interruption