Several international research studies have conclusively established that the aggressive application of nationally recommended prevention activities could significantly reduce the burden of disease in several areas. Immunization or vaccination program is one such critical areas.
Several ailments, which used to be so common all over the world, can now be effectively prevented through vaccination. The most common and serious vaccine-preventable diseases are: diphtheria, Haemophilus influenzae serotype b (Hib), hepatitis B and C, measles, meningitis, mumps, pertussis, poliomyelitis, rubella, tetanus, tuberculosis, rotavirus, pneumococcal disease and yellow fever. The list of the World Health Organization (WHO) indicates that vaccines are now available for 25 different diseases.
Thus, vaccination can save millions of lives and morbidity that such diseases still cause to a very large number of global population. Thanks to vaccines, two most scary diseases – small pox (totally) and polio (almost totally), have been eliminated from the world.
No doubt, why vaccination was voted as one of the four most important developments in medicine of the past 150 years, alongside sanitation, antibiotics and anesthesia by readers of the ‘British Medical Journal (BMJ)’ in 2007. It has been decisively proved that vaccines are one of the most successful and cost-effective public health interventions, which help preventing over 3 million deaths every year, throughout the world, topping the list in terms of lives saved.
In tandem, concerted efforts need to be made by both the industry and the Governments to improve affordable access to all these vaccines for a larger section of the population, especially in the developing world.
A crying need still exists:
Nevertheless, there is still a crying need for greater encouragement, more resource deployment and sharper focus towards newer vaccine development for many more dreaded and difficult diseases. One such area is malaria vaccine.
Some areas of new vaccine development:
Following is an example of some newer therapy areas where novel vaccines are now reportedly under development:
- Malaria vaccine
- Cancer vaccine
- AIDS
- Alzheimer’s disease
Malaria vaccine:
A July 24, 2015 article of the BBC News states, the ‘European Medicines Agency (EMA)’ gave a positive scientific opinion after assessing the safety and effectiveness of the first anti-malarial vaccine of the world – Mosquirix, developed by the British pharma major GlaxoSmithKline.
The vaccine reportedly targets the ‘P. falciparum’, the most prevalent malaria parasite and the deadlier of the two parasites that transmit the disease. At present, in the absence of any licensed vaccines for malaria, the main preventive measures to contain the spread of this parasitic disease are spraying of insecticides, use of other mosquito repellent and mosquito nets.
However, it was observed during its clinical trial that he best protection with this vaccine was achieved among children aged five to 17 months, receiving three doses of the vaccine a month apart, plus a booster dose at 20 months. In this group, cases of severe malaria were cut by a third over a four-year period, the report said.
Some concern was also expressed, as the effectiveness of the vaccine waned over time, making the booster shot essential, without which the vaccine did not cut the rate of severe malaria over the trial period. Moreover, the vaccine did not prove very effective in protecting young babies from severe malaria.
This caused a dilemma for the ‘World Health Organization (WHO)’. On the one hand, the stark reality of malaria killing around 584,000 people a year worldwide, and on the other, lack of conclusiveness in the overall results for this vaccine. Therefore, the world health body decided at that time to further consider about it, soon after the experts’ deliberation on whether to recommend it for children, among whom trials have yielded mixed results, gets completed.
The good news is, on November 18, 2016, Newsweek reported the announcement of the W.H.O, that Mosquirix will be piloted across sub-Saharan Africa in 2018, after a funding approval of US$ 15 million for this purpose.
Cancer vaccines:
According to the National Cancer Institute, which is a part of the National Institutes of Health (NIH) of the United States, cancer vaccines belong to a class of substances known as biological response modifiers. Biological response modifiers work by stimulating or restoring the immune system’s ability to fight infections and disease. There are two broad types of cancer vaccines:
- Preventive (or prophylactic) vaccines, which are intended to prevent cancer from developing in healthy people.
- Persistent infections with high-risk human papillomavirus (HPV) types can cause cervical cancer, anal cancer, oropharyngeal cancer, and vaginal, vulvar, and penile cancers. Three vaccines are approved by the US Food and Drug Administration (FDA) to prevent HPV infection: Gardasil®, Gardasil 9®, and Cervarix®.
- Chronic Hepatitis B virus (HBV) infection can lead to liver cancer. The FDA has approved multiple vaccines that protect against HBV infection, such as, Engerix-B and Recombivax HB, which protect against HBV infection only.
- Treatment (or therapeutic) vaccines, which are intended to treat an existing cancer by strengthening the body’s natural immune response against the cancer. Treatment vaccines are a form of immunotherapy.
- In April 2010, the USFDA approved the first cancer treatment vaccine. This vaccine, sipuleucel-T (Provenge®), is approved for use in some men with metastatic prostate cancer. It is designed to stimulate an immune response to prostatic acid phosphatase (PAP), an antigen that is found on most prostate cancer cells.
Another type of cancer vaccine is currently being developed, known as the Universal Cancer Vaccine.
- Universal Cancer Vaccine, June 1, 2016 issue of ‘The Independent’ reported that scientists of Johannes Gutenberg University in Germany have taken a “very positive step” towards creating a universal vaccine against cancer that makes the body’s immune system attack tumors as if they were a virus. The researchers had taken pieces of cancer’s genetic RNA code, put them into tiny nanoparticles of fat and then injected the mixture into the bloodstreams of three patients in the advanced stages of the disease. The patients’ immune systems responded by producing “killer” T-cells designed to attack cancer.
The vaccine was found to be effective in fighting “aggressively growing” tumors in mice. At the same time, such vaccines are fast and inexpensive to produce, and virtually any tumor antigen (a protein attacked by the immune system) can be encoded by RNA, the report said.
The analysts forecast the global cancer vaccines market to grow at a CAGR of 27.24 percent over the period 2014-2019.
HIV/AIDS Vaccine:
The 21st International AIDS Conference (AIDS 2016) held in Durban, South Africa from July 18 to 22, 2016, revealed that a vaccine against HIV will be trialed in South Africa later in 2016, after meeting the criteria needed to prove it, could help fight the epidemic in Africa. A small trial, known as HVTN100, took place in South Africa in 2015 to test the safety and strength of immunity the vaccine could provide, ahead of any large-scale testing in affected populations.
This development reportedly has its origin in a large landmark 2009 trial of RV 144 vaccine in Thailand, demonstrating the proof of concept that a preventive vaccine with a risk reduction of 31 percent could effectively work. The trial was supported by the World Health Organization (WHO) and UNAIDS. The clinical trial participants who received Vacc-4x, reportedly “experienced a 70 percent viral load decrease relative to their level before starting Anti-Retroviral Therapy (ART), compared with no notable reduction among placebo recipients.”
Alzheimer’s disease vaccine:
A vaccine for Alzheimer’s disease could be trialed in human within the next 3-5 years, after researchers from the United States and Australia have uncovered a formulation that they say successfully targets brain proteins, which play a role in the development and progression of the disease, states a July 18, 2016 report published in the ‘Medical News Today (MNT)’...............
To
read more, please click on this link
No comments:
Post a Comment