Graduating Vaccination from Children to All Age Groups - Daily Current Affair Article

CONTEXT:

Decades have seen child vaccination as its topmost agenda, but the Corona pandemic has changed the focus on adult vaccination where adults too are in danger due to widespread diseases like Covid-19. Such diseases will keep coming back into the world, thus, we need to be prepared for future outbreaks.

VACCINATION : INTRODUCTION

BASICS:

  • Definition:
  • A vaccine is a type of medicine that trains the body’s immune system so that it can fight a disease it has not come into contact with before. Vaccines are designed to prevent disease, rather than treat a disease once you have caught it.
  • How It Works:
  • A vaccine works by training the immune system to recognize and combat pathogens, either viruses or bacteria. To do this, certain molecules from the pathogen must be introduced into the body to trigger an immune response.
  • These molecules are called antigens, and they are present on all viruses and bacteria. By injecting these antigens into the body, the immune system can safely learn to recognize them as hostile invaders, produce antibodies, and remember them for the future. If the bacteria or virus reappears, the immune system will recognize the antigens immediately and attack aggressively well before the pathogen can spread and cause sickness.
  • Vaccines don't just work on an individual level, they protect entire populations. Once enough people are immunized, opportunities for an outbreak of disease become so low even people who aren't immunized benefit. Essentially, a bacteria or virus simply won't have enough eligible hosts to establish a foothold and will eventually die out entirely. This phenomenon is called "herd immunity" or "community immunity," and it has allowed once-devastating diseases to be eliminated entirely, without needing to vaccinate every individual.
  • Types of Vaccine: The key to vaccines is injecting the antigens into the body without causing the person to get sick at the same time. Scientists have developed several ways of doing this, and each approach makes for a different type of vaccine.
  • Live Attenuated Vaccines: For these types of vaccines, a weaker, asymptomatic form of the virus or bacteria is introduced into the body. Because it is weakened, the pathogen will not spread and cause sickness, but the immune system will still learn to recognize its antigens and know to fight in the future.
  • Advantages: Because these vaccines introduce actual live pathogens into the body, it is an excellent simulation for the immune system. So live attenuated vaccines can result in lifelong immunity with just one or two doses.
  • Disadvantages: Because they contain living pathogens, live attenuated vaccines are not given to people with weakened immune systems, such as people undergoing chemotherapy or HIV treatment, as there is a risk the pathogen could get stronger and cause sickness. Additionally, these vaccines must be refrigerated at all times so the weakened pathogen doesn't die.
  • Specific Vaccines:
  • Measles
  • Mumps
  • Rubella (MMR combined vaccine)
  • Varicella (chickenpox)
  • Influenza (nasal spray)
  • Rotavirus
  • Inactivated Vaccines: For these vaccines, the specific virus or bacteria is killed with heat or chemicals, and its dead cells are introduced into the body. Even though the pathogen is dead, the immune system can still learn from its antigens how to fight live versions of it in the future.
  • Advantages: These vaccines can be freeze dried and easily stored because there is no risk of killing the pathogen as there is with live attenuated vaccines. They are also safer, without the risk of the virus or bacteria mutating back into its disease-causing form.
  • Disadvantages: Because the virus or bacteria is dead, it's not as accurate a simulation of the real thing as a live attenuated virus. Therefore, it often takes several doses and "booster shots" to train the body to defend itself.
  • Specific Vaccines:
  • Polio (IPV)
  • Hepatitis A
  • Rabies
  • Subunit/conjugate Vaccines: For some diseases, scientists are able to isolate a specific protein or carbohydrate from the pathogen that, when injected into the body, can train the immune system to react without provoking sickness.
  • Advantages: With these vaccines, the chance of an adverse reaction in the patient is much lower, because only a part or the original pathogen is injected into the body instead of the whole thing.
  • Disadvantages: Identifying the best antigens in the pathogen for training the immune system and then separating them is not always possible. Only certain vaccines can be produced in this way.
  • Specific Vaccines:
  • Hepatitis B
  • Influenza
  • Haemophilus Influenzae Type B (Hib)
  • Pertussis (part of DTaP combined immunization)
  • Pneumococcal
  • Human Papillomavirus (HPV)
  • Meningococcal
  • Toxoid Vaccines: Some bacterial diseases damage the body by secreting harmful chemicals or toxins. For these bacteria, scientists are able to "deactivate" some of the toxins using a mixture of formaldehyde and water. These dead toxins are then safely injected into the body. The immune system learns well enough from the dead toxins to fight off living toxins, should they ever make an appearance.
  • Specific Vaccines:
  • Diphtheria
  • Tetanus
  • Conjugate Vaccines: Some bacteria, like those of Hib disease, possess an outer coating of sugar molecules that camouflage their antigens and fool young immune systems. To get around this problem, scientists can link an antigen from another recognizable pathogen to the sugary coating of the camouflaged bacteria. As a result, the body's immune system learns to recognize the sugary camouflage itself as harmful and immediately attacks it and its carrier if it enters the body.
  • Specific Vaccines:
  • Haemophilus Influenzae Type B (Hib)
  • DNA Vaccines: Still in experimental stages, DNA vaccines would dispense with all unnecessary parts of a bacterium or virus and instead contain just an injection of a few parts of the pathogen's DNA. These DNA strands would instruct the immune system to produce antigens for combating the pathogen all by itself. As a result, these vaccines would be very efficient immune system trainers. They are also cheap and easy to produce.
  • Specific Vaccines: DNA vaccines for influenza and herpes are currently in human testing phases.
  • Recombinant Vector Vaccines: These experimental vaccines are similar to DNA vaccines in that they introduce DNA from a harmful pathogen into the body, triggering the immune system to produce antigens and train itself to identify and combat the disease. The difference is that these vaccines use an attenuated, or weakened, virus or bacterium as a ride, or vector, for the DNA. In essence, scientists are able to take a harmless pathogen, dress it in the DNA of a more dangerous disease, and train the body to recognize and fight both effectively.
  • Specific Vaccines: Recombinant vector vaccines for HIV, rabies, and measles are currently being developed.

National Vaccine Policy of India

  • The policy lays down the guidelines for evidence-based research and introduction of vaccines in the Universal Immunisation Programme (UIP) in India.
  • Headed by N K Ganguly, former director general of Indian Council of Medical Research (ICMR), National Technical Advisory Group on Immunisation (NTAGI) appointed the committee.
  • Objectives:
  • To contribute to prevention of mortality and morbidity due to communicable diseases.
  • To ensure consistent delivery and administration of vaccines to everyone in need.
  • guide decision-making regarding various aspect of immunization, and to develop a long-term plan to strengthen the whole vaccine program in the country.
  • To achieve national self-reliance in vaccine research & development (R&D)
  • To achieve pre-eminence in the capabilities of the indigenous public sector for self-reliance.
  • To develop and use the interdisciplinary knowledge base.
  • To promote ethical conduct in the development, trials, adoption and administration of vaccines.
  • To develop a system for monitoring and compensating Adverse Events Following Immunisation (AEFI).
  • To enable India to play a leading role in the supply of affordable vaccines.
  • To synergize all relevant policies for effective implementation of the national vaccine policy.

National Technical Advisory Group on Immunization (NTAGI)

  • NTAGI is the highest advisory body on immunization in the country which consists of independent experts who provide recommendations on vaccines after reviewing data on disease burden, efficacy and cost-effectiveness of vaccines.
  • It was established by the Ministry of Health and Family Welfare (MoHFW) in 2001
  • The NTAGI includes a Standing Technical Sub-Committee (STSC).
  • The STSC is tasked with undertaking technical review of scientific evidence on matters related to immunization policy and programmes.
  • Final recommendations are drafted by the NTAGI taking into account the scientific review by the STSC and any other relevant evidence.

HISTORY OF ADULT VACCINATION

  • The first vaccine against smallpox in 1798 had always been for a far wider age group, including for adults.
  • However, soon after smallpox eradication and the launch of the Expanded Programme on Immunisation (EPI) across the world in the 1970s — and in India in 1978—there were concerted efforts to increase vaccine use and coverage in children

REASONS FOR PRIORITISATION OF CHILD VACCINATION

  • Scientifically, it has been found and proven that the benefit of most vaccines are greater, if administered earlier in life i.e. infancy and childhood.
  • For the remaining age groups including adults, vaccines are recommended for specific subgroups such as older people or those with specific health conditions.

Cons of this prioritisation:

  • Lately, review of available data has pointed that the increased childhood vaccination coverage has resulted in proportionately higher cases of Vaccine Preventable Diseases (VPDs) in the older age groups.

COVID 19 AS AN EXCEPTION

  • The COVID19 vaccines are exceptions in some sense. These are the first vaccines which have been recommended for all adults, who have been given priority over children. In fact, the jury is still out on whether, which age subgroup and when children should receive COVID19 vaccines

INITIATIVES FOR ADULT VACCINATION

PUBLIC SECTOR:

  • India conducted mass scale Japanase Encephalitis vaccination, for several years, in the endemic districts,which included the adult age group, when the outbreaks occurred in 2005-06.
  • Then, there had been a use of Swine Flu vaccines for health workers, though limited, during the H1N1 (2009) pandemic in 2009-10

PRIVATE SECTOR:

  • Association of Physicians of India and the Indian Society of Nephrology have released guidelines on adult vaccination.
  • These are voluntary and as the private sector share in vaccination in India is very small, understandably, the impact remains unknown and is likely to be low.

NEED OF ADULT VACCINATION

  • There is emerging scientific evidence on the need of booster doses in the adult age group for the vaccines administered in childhood.
  • The vaccines which have become available in the last two decades (which adults had not received as children), have potential to be beneficial.
  • As an example, there are more deaths due to pneumonia in adults than in children.
  • A proportion of those illnesses, hospitalisations and deaths — in all age groups — can be prevented by increasing coverage of currently licensed vaccines which prevents pneumonia and related complications.
  • Fortunately, these vaccines have become part of childhood vaccination programmes; however, the coverage and benefits need to be expanded to the identified high-risk adult population.
  • The available evidence has resulted in the global stakeholders agreeing to ‘the Immunization Agenda 2030’ which has emphasised that countries should consider extending the benefit of vaccines to all age groups.

COVID-19 AS AN OPPORTUNITY FOR ADULT VACCINATION

  • The COVID19 vaccination drive has brought our focus again to the possibilities of adult vaccination.
  • The initiatives should be taken to educate and create awareness amongst the public, healthcare providers and members of professional associations about currently available vaccines for adult age groups.
  • This can help people to make an informed choice and healthcare providers to share information with citizens.
  • Various training programmes and graduate and post-graduate teaching curricula should be revised to have content on adult vaccination.The current discourse should be used to plan and develop a national adult vaccination strategy and roadmap for India. It can be done through a few coordinated efforts.

SUGGESTIONS

  • First, the mandate of NTAGI needs to be expanded and subsume adult vaccination into it.
  • NTAGI needs to review the available scientific evidence and provide recommendations on adult vaccination in India.
  • These recommendations can be regularly revisited and revised once additional data become available.
  • A NTAGI subgroup on adult vaccination can also be constituted to facilitate the process.
  • Second, the VPD surveillance system and the capacity to record,report and analyse data on the disease burden and immunisation coverage need to be strengthened.
  • The focus has to be on analysing immunisation coverage and VPD surveillance data by age and other related stratifiers.
  • Third, the capacity of research and academic institutions to conduct operational research including the cost benefit analysis and to guide evidence informed decisions needs to be boosted.
  • Such analysis and evidence can be used by NTAGI in decision making processes.
  • Fourth, the process for developing and drafting a road map, possibly India’s national adult vaccination policy and strategy should be initiated.
  • Any such policy should be decided with the learnings and lessons from the ongoing COVID-19 vaccination drive as well.
  • Fifth, on a more operational level, the shortage of lifesaving rabies vaccine in India in 2019 is a reminder of the risk and vulnerability in vaccine supply.
  • To ensure vaccine security and be future ready for adult vaccination,the existing public sector vaccine manufacturing units in India should be revived and more need to be set up.

WAY FORWARD

The childhood vaccination programme is amongst the best performing government health programmes in India. In COVID-19 vaccination, it was the government facilities which have delivered 93%-95% of total vaccine shots. The current situation is a reminder and a lesson for the stakeholders to understand the future need. It is an opportunity for health policy makers in India to identify and institutionalise mechanisms on adult vaccination and aware adult citizens to make informed choices on currently available vaccines. It is time to plan for and expand the benefits of vaccines, for all age groups as part of the Universal Immunization Programme Plus in India. Drafting and developing a national adult vaccination policy and strategy for India could be one such concrete step in this direction.

Sources

  • The Hindu
  • Public health.org
  • MOHRW
  • NHM
  • Down to Earth
General Studies Paper 3
  • Science & Tech