User:Cleung1021/Multipurpose prevention technology

Lead
Multipurpose prevention technologies (MPTs) are a class of products designed to prevent various health issues simultaneously, often focusing on sexual and reproductive health which includes contraception, the human immunodeficiency virus (HIV) prevention, and other sexually transmitted infections (STIs) prevention such as genital infection by human simplex virus (HSV) infection and human papillomavirus (HPV) infection. For example, MPTs can combine contraception and HIV prevention, contraception and other STI prevention, or the prevention of multiple STIs. While the simultaneous use of multiple products against specific sexual or reproductive health issues is inconvenient and may affect adherence, the development of MPT in one single product can combat this issue.

These products can be utilized by individuals who wish to conceive, as well as breastfeeding and pregnant individuals not using contraceptives.

Article body
Types: A range of MPT products are in development since 2010. The development pipeline includes different designs, product types, and configurations. These include barrier methods, surfactant, polyanion, pH modifiers, and etc. Examples of MPT products that are available or in development are:

Prevalence:
 * Préservatif féminin.jpgCondoms - Male and female condoms are the only MPT products currently available. They are a non-hormonal form of MPT that combines contraception and HIV/STI preventions. Male condoms are 87% effective in preventing pregnancy in actual use, and up to 98% effective under perfect use, and provide more than 90% protection against STI pathogens.
 * Photo of Contraceptive Diaphragm.jpgDiaphragm with added microbicide - A diaphragm is a physical barrier that can be inserted into the vagina prior to sex that stops sperm from reaching the uterus. They are currently used in combination with gels and spermicides to add a chemical component to blocking sperm. In its usage as a MPT, once effect candidates for vaginal gels are develop, they can be used together to provide contraception as well as HIV/STI prevention.
 * Intravaginal ring (IVR) - IVRs are polyermic rings that are inserted into the vagina and release the drug into the surrounding tissue. Currently there are IVRs on the market that act solely as contraceptives, but IVRs that can act as MPTs are currently in development. IVRs with the combination of either tenofivir/levonorgestrel or dapivirine/levonorgestrel are currently being studied in attempts of developing an IVR that combines both contraception and HIV prevention.
 * Gel (rectal or vaginal) - Gels are topical formulations used to deliver a drug to the desired tissue. Studies are being done to test vaginal gels with different microbicides for their effectiveness at preventing HIV and STI transmissions.
 * Vaginal tablets (i.e., inserts) - Vaginal tablets and inserts can be used for both therapeutic and prophylaxis. They dissolve in the vaginal cavity after administration. Vaginal tablets and inserts contain hydrophilic polymers such as carbomers and sodium alginate to provide a mucoadhesive properties allowing time for the formulation to work. Vaginal tablets and inserts are easy to use and handle, and providing precise dosing and good stability. However, a applicator is needed for administration which increases the cost.
 * Vaginal films - Vaginal films are soft and thin sheets containing more than one active ingredients. They dissolve in the vaginal cavity after administration. Vaginal films contain bioadhesive polymers to allow time for drug release. There are immediate and sustained formulation for vaginal films. Vaginal films are easy to use and handle.
 * Microarray patches - A microarray patch is a patch with a layer of micro-needles on the surface that can inject the desired medication into the skin the patch is applied to. This allows developers to utilize drugs that are not orally available, and it also has the potential of allowing more convenient administration of drugs that may normally only be given through injections. Such patches are being developed to prevent pregnancy and HIV transmission, but there are limitations since the size of a patch that could inject enough of a medication to achieve these goals may not be practical.

HIV, other STIs, and unintended pregnancy continue to be a public health concern worldwide, all sharing a common link of exposure. The importance of MPTs has been recognized for some time now, and condoms serve as an excellent example. However, the potential impact of preventing HIV infection through condoms has been diminished due to lack of usage among females and males. As of 2022, approximately 39 million people worldwide are currently living with HIV ; around 374 million new cases of STIs arise each year, and nearly half (45%) of all pregnancies are unintended.

History:

STIs in humans have been documented since ancient times, with genetic evidence indicating HSV-2 infection over 1.5 million years ago. Similarly, the history of contraception also traces back to antiquity. The oldest male barrier contraceptives are condoms or penile sheaths, with the earliest forms of condoms being made from animal parts or chemically-treated linen. Italian anatomist Gabriele Falloppio claimed to have invented the linen sheath condom in 1564, with the intent to protect against the syphilis outbreak that devastated Europe. There were many other forms of condoms utilized by different ethnic groups, such as oiled silk paper by the Chinese and tortoise-shell, horn, or fine leather sheaths by the Japanese. It wasn't until the rubber vulcanization process invented by Charles Goodyear that the first rubber condom was made. In 1993, the female condom was introduced with a similar objective, to provide protection against STIs and unintended pregnancies. There have been many discussions around MPTs for decades now, but barrier methods remain the only MPT product widely available.

The MPT field emerged from the microbicide field, a natural extension from the microbicide field’s focus on women-controlled methods to prevent HIV acquisition. In 1998, the Alliance for Microbicide Development was formed; however, it was disbanded and funding for microbicide research was reduced after clinical trials for multiple microbicides did not show prevention of HIV transmission. In 2009, CAMI Health convened a multidisciplinary international meeting in Berkeley, California to formalize the MPT field which brought attention back to microbicides. The aim of the MPT was to prevent against any combination of unintended pregnancy, HIV and other STIs. In 2011, the first major funding opportunity for MPT development was released by the National Institutes of Health.

Opportunities:

MPTs provide prevention for multiple indications. Because of this, MPTs have the opportunity to revolutionize sexual health.

MPTs can help increase adherence to HIV pre-exposure prophylaxis (PrEP) by decreasing the number of clinic visits to address family planning and sexual health topics. Additionally, MPTs can reduce the stigma surrounding HIV and STI prevention by combining prevention for these indications into contraceptives, a less stigmatized product.

The successful development of MPTs could also pave the way for similar technologies to improve reproductive health more comprehensively. These advancements could encompass issues such as vaginal inflammation from infections, miscarriage and premature birth, cancer, menstrual cramps, or wound healing from trauma or childbirth.

A survey was done in parts of sub-Saharan Africa which indicated that 96% of surveyed women prefer MPTs over single indication products. Despite this preference, there is limited funding for MPTs, which can make it difficult for individuals to gain access and afford these products. Going forward, there are opportunities to improve accessibility to help ensure individuals who can benefit from these products are able to obtain them in an accessible and affordable manner.

References
 * 1) Lusti‐Narasimhan, M., Merialdi, M., & Holt, B. (2014). Multipurpose prevention technologies: maximising positive synergies. BJOG: An International Journal of Obstetrics & Gynaecology, 121(3), 251-251.
 * 2) ^ Friend, D. R. (2016). An update on multipurpose prevention technologies for the prevention of HIV transmission and pregnancy. Expert opinion on drug delivery, 13(4), 533-545.
 * 3) ^ Malcolm, R. K., Boyd, P., McCoy, C. F., & Murphy, D. J. (2014). Beyond HIV microbicides: multipurpose prevention technology products. BJOG: An International Journal of Obstetrics & Gynaecology, 121(s5), 62-69.
 * 4) ^ Young Holt, B., Romano, J., Manning, J., Hemmerling, A., Shields, W., Vyda, L., & Lusti‐Narasimhan, M. (2014). Ensuring successful development and introduction of multipurpose prevention technologies through an innovative partnership approach. BJOG: An International Journal of Obstetrics & Gynaecology, 121(s5), 3-8.
 * 5) ^ "RFA-AI-11-016: Combined Multipurpose Strategies for Sexual and Reproductive Health (R21/33)". grants.nih.gov