Among the current fields of research in Biotechnology, research on drugs and vaccines targeting viral diseases such as HIV/AIDs has been of major importance given the high prevalence of these diseases across the world. HIV (Human Immunodeficiency Virus) is a type of virus that causes AIDS (Acquired Immune-deficiency Syndrome) (HIV and AIDS, n. d). The virus devastates the body’s defense mechanism, leaving a victim highly susceptible to opportunistic infections such as those caused by bacteria, fungi, parasites, and viruses.
AIDS epidemic has presented a major challenge among researchers given the high rates of mutation and replication of HIV in host cells (ABU, DEAN, &ump; JEFF, 2010). In addition, limited access to antiretroviral drugs in some of the most affected regions such as the Sub-Saharan Africa has slowed down the fight against the epidemic. AIDS is associated with other devastating diseases such as Kaposi Sarcoma and liver diseases which calls for more research efforts to find an effective vaccine.
Apart from the increasing cases of HIV infection through sexual intercourse and drug injecting paraphernalia, mother-to-child transmission has also been cited as a major culprit (Majid, 2010). Despite a wide range of challenges facing the faculty of drug and vaccine development, considerable progress has been made. This paper presents the major challenges facing the area of viral disease research and specifically HIV/AIDS. It incorporates this discussion with a literature review of the research efforts that have been made towards tackling the challenges.
It is almost three decades since HIV and AIDS was discovered and the lives of millions of people have been claimed by the pandemic. At the same time, the pandemic has had a deleterious impact on the health patterns in the world as it has changed the progression patterns of various diseases (Gould &ump; Woods, 2003). According to Eilbert (2008), more than 20 million people have succumbed to HIV and AIDS since it was discovered back in 1981. Eilbert also asserts that the pandemic is leading in terms of causing many deaths with the most affected being people aged between 15 and 59 years (2008).
The number of infected people across the world stands at 40 million with about 67% of this population living in the sub-Saharan Africa. In Botswana for example, the infection rate among the adult population is 37%. In the United States, the current level of HIV infection is about 1 million and more than 0. 5 million people have died from the disease (Eilbert, 2008). The rate of HIV infection among children has also escalated especially in developing countries. Research has associated this increase with the rise in the number of women who have attained childbearing age but who are HIV-infected (Claudia, 2001).
However, considerable steps have been made to reduce cases of mother to child transmission both during birth and breastfeeding. According to Rivera (2011), transfusion of infected blood products was one of the ways through which children got infected with HIV before 1985. However, due to intensive research on screening methods, this means of transmission of the virus has been eliminated (Rivera, 2011). Nevertheless, vertical transmission of HIV remains a major problem as indicated by the World Health Organization data. Rivera notes that the 2009 WHO report estimated the number of children living with HIV to be 2.
5 million. During the same year, cases of new infection were 370, 000 (2011). Though this is a big number, records depict a drop of 24% from the 2004 data. This is an indication of efforts that have been made to reduce new cases of vertical infection (Bennett, 2011). Through research, Bennett (2011) notes that two strains of HIV that is HIV type 1(HIV-1) and HIV type 2 (HIV-2) have been identified. In addition, in an effort to concentrate resources in the most important are, research has helped to identify HIV-1 as the most common strain among HIV positive patients.
However, Rivera points out that there are cases where AIDS patients may test positive for both strains of HIV (2011). One area of research in curbing HIV infection and progression to AIDS has been antiretroviral therapy. According to Eilbert, research has facilitated the discovery of about 24 new types of antiretroviral drugs since the mid 1990s (2008). These developments have achieved marked progress in fighting HIV/AIDS as the disease has been transformed into a chronic illness that can be relatively suppressed as opposed to being uniformly fatal.
Eilbert underscores this point by noting that life expectancy following diagnosis of a patient with HIV was 7 years in 1993 compared to the current 24 years (2008). Despite these remarkable achievements in research, Eilbert (2008) alludes to the fact that prospects of creating an effective HIV vaccine remain elusive given that viral isolates exhibit wide genetic variability. Availability of adequate funding to facilitate more intensive and focused research has also been a challenge despite several organizations committing colossal sums of money towards HIV/AIDS research.
Among these organizations include the National Institutes of Allergy and Infectious Diseases (NIAID) which distributes its funds for HIV/AIDS research via its Division of AIDS (DAIDS) (Georgiev, 2009, p. 337). The National Institutes of Health (NIH) also remain instrumental in providing resources for AIDS research. Georgiev (2009, p. 337) hints the problem of antibiotic resistance as presenting a major challenge particularly in light of the global threat of tuberculosis epidemic. Georgiev notes that HIV/AIDS epidemic has been fueled mainly by tuberculosis epidemic since the early 1990s (2009, p. 337).
Research has shown that people who are infected with HIV become highly susceptible to TB among other opportunistic infections. It is estimated that the sub-Saharan Africa has encountered millions of new TB cases as a result of the high prevalence of HIV/AIDS in the region (Diacon &ump; Luthi, 2011). This problem has been aggravated by the development of multi-drug resistant tuberculosis (MDR-TB) as well as extreme drug resistant tuberculosis (XDR-TB). These conditions develop mainly due to lack of adherence to drug prescription, leading to fast replication of bacteria that have gradually mutated to attain drug resistance.
Tuberculosis has been cited as the major cause of death among HIV/AIDS infected patients. This challenge calls for concerted efforts towards developing aggressive treatment regimes for TB menace in HIV/AIDS patients (Tuberculosis and MDR-TB, n. d). Among the top items on the list of agenda for NIAID include developing more effective ways of preventing vertical transmission of HIV/AIDS as well as developing a wide range of effective antiretroviral drugs. It is also in the interest of NIAID to ensure that effective, safe, and cost effective HIV vaccines are developed in a bid to prevent HIV infection.
Research has made a lot of progress in fighting the major obstacle of drug resistance and widespread genetic variability of rapidly mutating viral strains. Greater efficacy has been found in using combination therapy whereby different drugs acting through diverse mechanisms are administered as opposed to monotherapy where a single drug is used (Jucker, 2001, p. 4). Jucker (2001, p. 4) notes that combined therapy has a number of advantages over monotherapy including reduction of side effects, dosages, and chances of a virus developing resistance.
At the same time, combined therapy triggers synergistic effect which contributes to greater drug efficacy. Montefiori, Barouch, &ump; Letvin (2002) indicate that researchers have developed diverse ways of fighting HIV, including the use of reverse transcriptase inhibitors. However, the major obstacle encountered in this approach is the significant levels of toxicity to the host and chances of drug resistance of the virus due to mutations (Huang &ump; Chen, 2010). Among the most commonly used inhibitors of HIV reverse transcriptase include stavudine, zidovudine, and zalcitabine (Jucker, 2001, p.4).
However, Jucker (2001) does not dismiss the fact that inhibitors of reverse transcriptase play a major role in blocking an early step in the replication cycle of HIV. This is especially evident in newly-infected cells. However, Jucker (2001) cautions that antiretroviral drugs that act on the basis of this mechanism cannot prevent virus production in situations where viral DNA has already been transcribed and integrated into the host DNA. Recent developments in HIV/AIDS research have focused on overcoming this challenge.
The most significant development is the discovery of new drugs that would target HIV protease (John, Wang, Chen, &ump; Shih, 2006). These drugs have found important use in combination therapy and have revived the hopes of achieving effective ways of preventing HIV replication. Jucker (2001, p. 6) indicates that through relentless efforts by researchers in this area, three approaches have been applied in designing protease inhibitors. The first approach is transition-state mimetic.
This approach entails the use of phosphinic acid, reduced amide, difluoromethylketone, hydroxyethylene dipeptide isostere, hydroxyethylcarbonyl mimetics, statine, hydroxyethylamine, and difluoromethylketone (Jucker, 2001, p. 6). In the second approach, Jucker (2001, p. 6) notes that researchers base their research on rotational symmetry which is two-fold. This relies on the native enzyme as well as the interaction of the protease inhibitor through specific hydrophobic interactions and hydrogen bonds. In this new development, researchers have realized the need to improve HIV protease inhibitors’ pharmacokinetic profile.
To achieve this, Jucker alludes to the use of non-peptidal strategy which is based on the first two approaches. There are a number of protease inhibitors that are currently available on the market. These include Fortovase, indinavir sulfate, saquinavir mesylate, and amprenavir (2001, p. 6). This paper has discussed the various trends in HIV/AIDS infection and some of the major factors contributing to these trends. It has also highlighted the major challenges faced by HIV/AIDS research and some of the steps that have been made to overcome these challenges.
It is noted that the fight against HIV/AIDS has been complicated by the complexity of the viral genome. In addition, development of drug resistance in viral strains has also posed a major set back in finding effective vaccines and drugs. Rampant spread of multi-drug resistant TB especially in the sub-Saharan Africa has also had a toll on HIV/AIDS research. However, researchers have applied different approaches including reverse transcriptase inhibitors and HIV protease inhibitors to develop a remedy for the pandemic.