New Vaccines on the Horizon: Technological Advances and Their Potential Public Health Impact
Vaccines: Public Health Impact and Success
Vaccines are among the most affordable and effective health care interventions available in the fight against communicable diseases today. The development and widespread use of vaccines have resulted in substantial progress against some of the most devastating infections of mankind. The previous success of Smallpox eradication, current progress towards global Polio eradication and reduction in Measles mortality globally are testimony to the public health benefits of vaccination and immunization.
Small Pox: Death of a Disease
Indeed, the world's only complete victory over an infectious agent resulted from a vaccine. Smallpox, the cause of significant mortality and morbidity more than any other infectious disease at the time, was eradicated from the world in the late 1970s following a well-planned and highly effective vaccination campaign.
Research and New Technologies in Vaccine Development
New vaccines are possible with increasing knowledge of the immune system, advances in vaccine technology and adjuvant development. The history of scientific enquiry in vaccine research has led to today’s carefully regulated vaccine development process. Standards for research into vaccine studies have become more stringent and rigorous. Vaccine development is a long, complex process, lasting about 10 to 15 years. With advanced scientific innovation enabling new vaccines to protect against previously unpreventable infectious diseases, the potential public health impact of vaccination is increasing continually. The technology behind vaccine development is evolving rapidly. Advances including new combination vaccine, presentations that offer ease and speed of delivery, and novel adjuvants to address some of the most difficult immunological challenges by improving the strength and duration of the protection given by vaccines can indeed make many more diseases vaccine preventable in future.
New innovations in vaccine technology and new information about how the immune system works make this an exciting time in the field of vaccine research and development, especially for vaccine trials in infectious diseases. Effective vaccines against Meningitis, Pneumonia, Rotavirus and human Papilloma virus are now available. There has been considerable progress in research towards developing vaccines against the “big three” – Malaria, HIV and TB. With the threat of drug-resistant TB, an effective TB vaccine is greatly needed, and many TB vaccines are now in clinical trials that would have a local as well as global impact.
New areas in current vaccine research include:
- Developing effective vaccines against diseases yet to be controlled
- New technologies such as DNA vaccines and use of adjuvants
- Newer and easier delivery methods such as aerosol vaccines, or vaccine patches.
New exciting developments such as DNA vaccines can potentially lead to effective and long- lasting immunity. These work by inducing immunity following injection of the DNA needed to make a specific portion of the pathogen in the vaccine recipient. These vaccines would have very few side effects because the vaccine only uses the necessary component of the bacteria or virus to make a small amount of antigen.
Another area of research is development of a vaccine for the vulnerable and high-risk groups such as pregnant women, infants and those with immune-compromised conditions.
Adjuvants are vaccine additives that stimulate the immune system. Discovery of new adjuvants can make existing vaccines more effective. The synergy of an adjuvant with a given antigen within a vaccine can optimize the interaction of the vaccine with the immune system to obtain more targeted, broader and/or longer-lasting immune responses. There are several adjuvants under clinical trials for diseases such as influenza, cancers and HIV.
Flu Vaccine: Hope for Future
Respiratory infections like Influenza and Pneumonia are particularly dangerous for children and the elderly, resulting in significant mortality every year. Because Influenza mutates continuously, it alters its appearance to the immune system by changing the proteins in its outer layer, the portion of the virus that the cells of the immune system use to recognize the virus. However, a few of these outer proteins do not change. Scientists are using these proteins to develop a multi-year vaccine with the hope of creating a universal Flu vaccine.
Newer and Easier Delivery Methods
In order to reduce inconvenience of an injection, needle- and pain-free vaccines are being developed. There are vaccines that can be given as a nasal spray or taken orally. A further breakthrough in new form of vaccine delivery is the vaccine patch. These can be self-administered and are convenient not only for those with a fear of needles, but also for mass distribution, especially in an outbreak control situation.
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Below are some of the recent advances in vaccine research that can have huge public health impact globally.
1. Dry powder Measles vaccine shows promise in early trials
Dry powder Measles vaccinations have proven to be safe for humans. The new form of vaccines will be easier to transport and administer compared to the current injectable vaccines.
(Photo : Glenn Asakawa / University of Colorado
A dry delivery measles vaccine has now completed successful phase I clinical trial. The study enrolled 60 adult males aged 18 to 45 years who were already seropositive for the measles antibody. Results showed no clinically relevant side effects. There was also evidence of a positive immune response to vaccination from the powder.
This vaccine is available as an inhalable dry powder which eliminates the problems associated with administering Measles vaccine conventionally, such as the need for liquid storage, possible contamination (as this does not require reconstituting the vaccine), or disposing sharps and vaccine wastes. Also, the cold chain is no longer required. According to researchers, this vaccine can be safely stored for six months to four years at room temperature or in a refrigerator. This has the potential to have a huge impact on low and middle-income countries with high Measles burden by making vaccine delivery easier in resource constrained countries like India. However, further larger studies are needed to find out if these results are relevant in other settings.
2. World’s First Dengue Vaccine, CYD-TDV
A female Ades aegypti (Dengue mosquito) taking a bloodmeal
India faces a huge public health problem in the form of Dengue, which is accounting for significant hospitalization and death. In India the number of deaths due to Dengue has increased from 80 in 2008 to 242 in 2012 and a major Dengue outbreak in 2013 with more than 70,000 cases, as officially reported. The alarming number of reported cases has an adverse effect on the Indian economy as well, in terms of hospitalization costs and disability-adjusted life years (DALYs), imposing a burden of $1.1 million every year.
The results of a phase III clinical trial of a potential new Dengue vaccine, CYD-TDV, has demonstrated that it provides 56 percent protection against the disease in Asian children. The study involved 10,275 healthy children aged 2 to 14 years who were randomly assigned to receive three injections of the CYD-TDV vaccine (6851) or a placebo (3424) at 0, 6 and 12 months, and followed for up to two years. In India, where standards of cleanliness and proper sanitation are poor, the vaccine will potentially prevent millions of people from contracting the infection.
3. Malaria Vaccine, RTS,S
Malaria is a huge public health problem in India with an estimated 46,800 deaths in 2010. As per the World Malaria Report 2011, over 70 percent of India's population is at risk of Malaria. In the current scenario of a rising Malaria burden, a vaccine can serve as a boon to the nation.
The candidate Malaria vaccine, RTS,S aims to trigger the body’s immune system to defend against the Plasmodium falciparum malarial parasite when it first enters the human host’s bloodstream and/or when the parasite infects liver cells. The results show that RTS,S continued to provide meaningful protection over 18 months to babies and young children across different regions of Africa. While there was some decline in vaccine efficacy over time, considering the global Malaria burden, the vaccine can have a tremendous public health impact on reducing childhood mortality due to Malaria worldwide.
The Times of India: 'Rotavirus vaccine can save 12k kids in UP every year’
Amit Ghosh, Mission Director of National Health Mission, Uttar Pradesh (UP), stated that the rotavirus vaccine would be introduced in the state in the second phase of introduction, and will save at least 12,000 children below five years of age each year in the state.
The Times of India: Vaccine to prevent diarrhoea in infants launched in 4 states
Addressing a media workshop on rotavirus vaccine in Odisha, Dr. Nirmala Dei, Director of Family Welfare, Government of Odisha, announced that the vaccine will be given to all the children free of cost once introduced, and will help prevent the diarrhoea burden among infants in the state.
The New Indian Express: UIP to Cover Pneumonia: Sharma
Addressing the RVV launch in Odisha, Union Health Secretary Bhanu Pratap Sharma noted that the government is in a process of introducing the pneumonia vaccine under the Universal Immunisation Programme (UIP).
Cervical cancer vaccine program to be launched
Chennai in Tamil Nadu ranks second among the metros to have the highest incidence of cervical cancer. Reportedly, 17 out of one lakh women suffer from cervical cancer. Soon, the state could become the second in India to launch the Human Papilloma Virus (6HPV) vaccine as a health programme for school children.
A report in The New Indian Express cites a senior official in the TN Health and Family Welfare Department as saying that discussions are at an early stage and post the assembly elections, a decision would be made. According to the daily, plans are on in Tamil Nadu to launch the vaccine under the universal immunisation programme and there are plans for rotavirus too.
Union Health Minister JP Nadda had said in the Lok Sabha that an estimated 62,416 women died of cervical cancer in 2015-16. The daily added that cervical cancer accounted for 24 per cent of all cancer cases in women in India and 25 per cent of death worldwide.
Among the metros, Bangalore had the highest incidence of cervical cancer with 19 in one lakh women suffering from it and Delhi ranked third with 15 cases in one lakh women. In India, the highest incidence of cervical cancer was in Aizwal district, capital of Mizoram, which topped the list with 24 women in one lakh being diagnosed with cervical cancer.
The Delhi government is in touch with two pharmaceutical companies - GlaxoSmithKline (GSK) and MSD. Since the vaccine is not manufactured in India, it would need to be procured from outside. The New Indian Express quoted Dr Shafi Kolhapure, GM-Medical Affairs, GSK Biologicals, India, as saying that the Delhi Health Minister Satyendar Jain had announced his government’s decision at a recent international workshop and they would have to call for tenders.
The daily also quoted the research paper by Aswathy Sreedevi, co-author of “Epidemiology of cervical cancer with special focus on India”. According to her research, the north-eastern districts of Tamil Nadu showed a high incidence of cervical cancer and penile cancer due to HPV.
Mission Indradhanush: Child immunization rate rose by 6%
There has been more than 6% increase in the number of fully immunized children in the country as compared to 2014 under Mission Indradhanush. The third phase of Mission Indradhanush was launched on the World Health Day, April 7 by the Ministry of Health and Family Welfare.
In the preceding two phases, out of an estimated 85-90 lakh children who were left out of the immunization program, 38.7 lakh children were fully immunized and 1.48 crore children were reached out in the entire drive. Compared to one per cent increase of fully immunized children previously, this year has witnessed a jump of almost 6 per cent.