{"id":4147,"date":"2026-01-05T09:19:54","date_gmt":"2026-01-05T03:49:54","guid":{"rendered":"https:\/\/vajiramandravi.com\/upsc-exam\/?p=4147"},"modified":"2026-01-06T12:06:46","modified_gmt":"2026-01-06T06:36:46","slug":"vaccine","status":"publish","type":"post","link":"https:\/\/vajiramandravi.com\/upsc-exam\/vaccine\/","title":{"rendered":"Vaccine, Definition, Types, Working, Challenges, UPSC Notes"},"content":{"rendered":"

Vaccines<\/strong>\u00a0stand as one of the\u00a0paramount medical breakthroughs in our history<\/strong>. They function by presenting the body with a\u00a0harmless version or fragment of a pathogen,<\/strong>\u00a0activating the immune system. This equips the body to identify and fight the real pathogen later on.\u00a0Vaccines have been instrumental in curbing, diminishing, or even wiping out diseases like smallpox, polio, and measles<\/strong>. Their extensive application has\u00a0saved countless lives and substantially lessened the impact of infectious diseases.<\/strong>\u00a0Ongoing scientific endeavours strive to address continually changing and newly emerging diseases.<\/p>\r\n

Historical Background of Vaccination<\/h2>\r\n

For ages, people have sought methods to shield one another from lethal illnesses. Since the 15th century, communities globally have tried to fend off diseases by deliberately introducing healthy individuals to smallpox, a technique termed\u00a0variolation<\/strong>.<\/p>\r\n

Development of Vaccine<\/strong><\/h3>\r\n

Significant events in the development of vaccines:<\/p>\r\n

    \r\n\t
  • 1796 - Smallpox:<\/strong>\u00a0Edward Jenner used cowpox material to create immunity to smallpox, marking the birth of the first true vaccine.\r\n\r\n
      \r\n\t
    • The term \u2018vaccine\u2019 was later coined, taken from the Latin word for cow, Vacca.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
    • 1885 - Rabies:<\/strong>\u00a0Louis Pasteur develops the first rabies vaccine after successfully vaccinating a boy bitten by a dog.<\/li>\r\n\t
    • 1890 - Diphtheria:<\/strong>\u00a0Emil von Behring and Shibasaburo Kitasato produce an antitoxin serum, laying the groundwork for the diphtheria vaccine.<\/li>\r\n\t
    • 1921 - Tuberculosis (BCG):\u00a0<\/strong>Albert Calmette and Camille Gu\u00e9rin developed the BCG vaccine against tuberculosis.<\/li>\r\n\t
    • 1952 - Polio:\u00a0<\/strong>Jonas Salk introduced the inactivated polio vaccine (IPV); Albert Sabin later developed the oral polio vaccine (OPV).<\/li>\r\n\t
    • Various efforts taken by WHO for vaccination include<\/strong><\/li>\r\n\t
    • Intensified Smallpox Eradication Programme (1967):<\/strong>\u00a0An initiative aimed at eradicating smallpox in over 30 countries through surveillance and vaccination.<\/li>\r\n\t
    • Essential Programme on Immunization (1974)<\/strong>: Established to develop and boost immunisation programs globally.\r\n\r\n
        \r\n\t
      • Initially targeted diseases like diphtheria, measles, polio, tetanus, tuberculosis, and whooping cough.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
      • Smallpox Eradication Declaration (1980)<\/strong>: WHO declared the world free from smallpox after coordinated vaccination efforts.<\/li>\r\n\t
      • Global Polio Eradication Initiative (1988):<\/strong>\u00a0Aims to eradicate polio worldwide.\r\n\r\n
          \r\n\t
        • Achieved eradication in several regions, with ongoing efforts in remaining endemic areas.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
        • GAVI (2000):\u00a0<\/strong>The Global Alliance for Vaccines and Immunisation (GAVI) is a coalition of various stakeholders (WHO, UNICEF, the World Bank, civil society organisations, vaccine manufacturers, and private sector like the Bill & Melinda Gates Foundation); It was created in 2000 to improve access to new and underused vaccines for children living in the world's poorest countries.<\/li>\r\n<\/ul>\r\n

          Working of Vaccine<\/strong><\/h3>\r\n
            \r\n\t
          • Antigen introduction:<\/strong>\u00a0Vaccines administer a safe part (antigen) of the infectious agent (like a segment of a virus or bacteria) to the body.<\/li>\r\n\t
          • Activation of immunity:<\/strong>\u00a0Upon detecting this unfamiliar antigen, the body triggers an immune reaction.<\/li>\r\n\t
          • Antibody generation:<\/strong>\u00a0To counteract the introduced antigen, the immune system forms specific proteins known as antibodies.<\/li>\r\n\t
          • Creation of memory cells:<\/strong>\u00a0Certain cells in the immune system, termed memory cells, are developed to retain information about the pathogen.<\/li>\r\n\t
          • Sustained defence:<\/strong>\u00a0These memory cells persist in the body, offering prolonged defence against that particular pathogen.<\/li>\r\n\t
          • Future encounters:\u00a0<\/strong>When the individual comes into contact with the actual pathogen later on, the immune system is primed to swiftly generate antibodies to fend it off.<\/li>\r\n\t
          • Enhanced immune reaction:\u00a0<\/strong>Memory cells ensure that the body's immune reaction is quicker and more potent upon later exposure.<\/li>\r\n<\/ul>\r\n

            Types of Vaccines<\/h2>\r\n

            Vaccines are classified based on composition and administration methods, they are essential for disease prevention.<\/p>\r\n

            Based on Compositions<\/strong><\/h3>\r\n

            Based on composition vaccines are classified as:<\/p>\r\n

            \r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
            About<\/strong><\/td>\r\nWorking<\/strong><\/td>\r\nAdvantage\/Disadvantage<\/strong><\/td>\r\nExamples<\/strong><\/td>\r\n<\/tr>\r\n
            Inactivated vaccine<\/strong>: Use viruses or bacteria that have been\u00a0killed or rendered non-functional.<\/strong><\/td>\r\n\r\n

            - Dead pathogens are identified as\u00a0foreign invaders by the immune system.<\/strong><\/p>\r\n

            - Production of\u00a0antibodies and memory cells\u00a0<\/strong>ensures response to future exposures.<\/p>\r\n<\/td>\r\n

            		\r\n

            - Advantages\u00a0<\/strong><\/p>\r\n

            - Safer for people\u00a0with weakened immune systems or those who've had an organ transplant.<\/strong><\/p>\r\n

            - Don't require refrigeration<\/strong>\u00a0making transportation easier.<\/p>\r\n<\/td>\r\n

            		\r\n

            The polio vaccine (IPV).<\/strong><\/p>\r\n

            , Hepatitis A vaccine<\/strong>\u00a0and\u00a0Rabies vaccine.<\/strong><\/p>\r\n<\/td>\r\n<\/tr>\r\n

            \r\n

            - Disadvantages\u00a0<\/strong><\/p>\r\n

            - Might require\u00a0booster shots to maintain immunity over time<\/strong>.<\/p>\r\n

            - Weaker immune response<\/strong>\u00a0compared to live vaccines.<\/p>\r\n<\/td>\r\n<\/tr>\r\n

            Attenuated Vaccine<\/strong>: Made from a\u00a0live pathogen that's been weakened.\u00a0<\/strong><\/td>\r\n\r\n

            - They replicate within the body.\u00a0mimicking a natural infection<\/strong><\/p>\r\n

            - Stimulating a\u00a0robust immune response.<\/strong><\/p>\r\n<\/td>\r\n

            		- Advantage:\u00a0<\/strong>Often confers\u00a0long-lasting immunity\u00a0<\/strong>with just one or two doses.<\/td>\r\n\r\n

            Measles, mumps, rubella (MMR) vaccine; Yellow Fever vaccine;\u00a0<\/strong><\/p>\r\n

            Oral Polio vaccine\u00a0(OPV).<\/strong><\/p>\r\n<\/td>\r\n<\/tr>\r\n

            \r\n

            - Disadvantage\u00a0<\/strong><\/p>\r\n

            - Not\u00a0<\/strong>suitable for people with weakened immune systems.<\/p>\r\n

            - Possibility of mutation\u00a0<\/strong>back to virulent state.<\/p>\r\n<\/td>\r\n<\/tr>\r\n

            Toxoid vaccines:\u00a0<\/strong>They are derived from toxins\u00a0targeting the toxin bacteria produce.<\/strong><\/td>\r\n\r\n

            - The immune system recognizes the\u00a0detoxified toxin as a threat.<\/strong><\/p>\r\n

            - Specific antibodies are produced to\u00a0neutralise the actual toxin.\u00a0<\/strong><\/p>\r\n<\/td>\r\n

            		\r\n

            - Advantages<\/strong><\/p>\r\n

            -\u00a0No risk of causing the disease<\/strong>\u00a0they're meant to prevent.<\/p>\r\n

            - Typically\u00a0more stable than live vaccine<\/strong>s and don't require stringent refrigeration.<\/p>\r\n<\/td>\r\n

            		Diphtheria\u00a0<\/strong>and tetanus vaccines are examples of toxoid vaccines.<\/td>\r\n<\/tr>\r\n
            \r\n

            - Disadvantages<\/strong><\/p>\r\n

            - It might\u00a0limit the overall immune response<\/strong><\/p>\r\n<\/td>\r\n<\/tr>\r\n

            Subunit vaccine:\u00a0<\/strong>It contains\u00a0only specific pieces\u00a0<\/strong>rather than whole organism.<\/td>\r\nThe immune system\u00a0responds to the fragments\u00a0<\/strong>by producing antibodies. - The body swiftly recognizes and\u00a0combats it using these antibodies.<\/strong><\/td>\r\n\r\n

            - Advantages\u00a0<\/strong><\/p>\r\n

            -\u00a0minimal risk of the vaccine-causing<\/strong>\u00a0disease.<\/p>\r\n

            - Create a strong immune response.<\/p>\r\n<\/td>\r\n

            		The Hepatitis B vaccine<\/strong><\/td>\r\n<\/tr>\r\n
            \r\n

            - Disadvantages\u00a0<\/strong><\/p>\r\n

            - Might require booster shots.<\/p>\r\n

            -\u00a0Complex production process\u00a0<\/strong><\/p>\r\n

            - Immune response is narrower<\/p>\r\n<\/td>\r\n<\/tr>\r\n

            Conjugate vaccine:\u00a0<\/strong>Fight bacterial infections, caused by\u00a0bacteria with polysaccharides (sugar) coatings.<\/strong><\/td>\r\n\r\n

            - Develop\u00a0a carrier protein<\/strong>\u00a0which is more recognizable to the immune system.<\/p>\r\n

            The immune system responds\u00a0more vigorously\u00a0<\/strong>to the protein-linked polysaccharide.<\/p>\r\n<\/td>\r\n

            		\r\n

            - Advantages\u00a0<\/strong><\/p>\r\n

            - Enhance the immune response of infants and young children.<\/p>\r\n

            - Induces a\u00a0longer-term immune response.\u00a0<\/strong><\/p>\r\n<\/td>\r\n

            		The Haemophilus influenzae type b (Hib)\u00a0<\/strong><\/td>\r\n<\/tr>\r\n
            \r\n

            - Disadvantage<\/strong><\/p>\r\n

            - Linking polysaccharides to proteins is a\u00a0complex process.\u00a0<\/strong><\/p>\r\n<\/td>\r\n<\/tr>\r\n

            Heterotypic vaccine:\u00a0<\/strong>Immunises the host with a different but related pathogens or antigens.<\/td>\r\n- The Immune system that recognises certain similarities between the vaccine agent and the targeted pathogen.<\/td>\r\n\r\n

            - Advantages<\/strong><\/p>\r\n

            - Act against multiple pathogens using a single vaccine.<\/p>\r\n

            - Reduces the need for the development of multiple vaccines<\/p>\r\n<\/td>\r\n

            		The BCG vaccine- protects<\/strong>\u00a0against tuberculosis and leprosy<\/td>\r\n<\/tr>\r\n
            \r\n

            - Disadvantages<\/strong><\/p>\r\n

            - Efficacy is less than a single pathogen vaccine Unpredictable - Cross-reactivity can complicate the vaccine development process.<\/p>\r\n<\/td>\r\n<\/tr>\r\n

            mRNA vaccine:\u00a0<\/strong>Uses synthetic mRNA to produce a protein that mimics a part of the target pathogen.<\/td>\r\n\r\n

            - The\u00a0vaccine delivers mRNA sequences into cells.\u00a0<\/strong><\/p>\r\n

            - Host cells\u00a0produce the target protein.\u00a0<\/strong><\/p>\r\n

            - The production of\u00a0antibodies and the activation of T-cells.<\/strong><\/p>\r\n

            - Formation\u00a0of memory cells\u00a0<\/strong><\/p>\r\n<\/td>\r\n

            		\r\n

            - Advantages:<\/strong><\/p>\r\n

            - Faster development when the genetic sequence is known.<\/p>\r\n

            - There's no risk of causing the disease in the vaccinated person.<\/p>\r\n

            - Easy to modify the mRNA sequence<\/p>\r\n<\/td>\r\n

            		Pfizer-BioNTech and Moderna\u00a0<\/strong>COVID-19 vaccines andemic.<\/td>\r\n<\/tr>\r\n
            \r\n

            - Disadvantages:\u00a0<\/strong><\/p>\r\n

            -\u00a0<\/strong>Some require ultra-cold storage.<\/p>\r\n

            - Long-term effects are still under study.<\/p>\r\n<\/td>\r\n<\/tr>\r\n

            Viral vector vaccine:\u00a0<\/strong>Utilise an altered form of another virus as a vector to provide protection.<\/td>\r\n\r\n

            -The virus's\u00a0genetic material is modified.<\/strong>\u00a0- Human cells are used to\u00a0produce the target protein<\/strong>.<\/p>\r\n

            -An immune response which\u00a0produces antibodies<\/strong><\/p>\r\n<\/td>\r\n

            		\r\n

            - Advantage-\u00a0<\/strong><\/p>\r\n

            - Robust\u00a0<\/strong>immune response<\/p>\r\n

            - No risk of causing diseases<\/p>\r\n<\/td>\r\n

            		The Oxford-AstraZeneca COVID-19 vaccine<\/strong><\/td>\r\n<\/tr>\r\n
            \r\n

            - Disadvantage-<\/strong><\/p>\r\n

            -\u00a0<\/strong>Less effective in case of\u00a0pre-existing immunity\u00a0<\/strong><\/p>\r\n

            - Complex production<\/strong><\/p>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/figure>\r\n

            Based on Administration<\/strong><\/h3>\r\n

            Based on administration vaccines are classified as:<\/p>\r\n

            \r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
            About<\/strong><\/td>\r\nRoute of Administration<\/strong><\/td>\r\nAdvantages\/Disadvantages<\/strong><\/td>\r\nExamples<\/strong><\/td>\r\n<\/tr>\r\n
            Injectable Vaccines<\/strong><\/td>\r\nInjected below\u00a0skin, muscle and skin's dermal layer.\u00a0<\/strong><\/td>\r\nAdvantage<\/strong>: Produces\u00a0strong systemic immune response<\/strong><\/td>\r\nMMR Vaccines, hepatitis B, and BCG Vaccines<\/strong><\/td>\r\n<\/tr>\r\n
            Disadvantage:<\/strong>\u00a0Causes\u00a0soreness at injection site.<\/strong><\/td>\r\n<\/tr>\r\n
            Oral Vaccines<\/strong><\/td>\r\nTaken by mouth\u00a0in liquid form or as a pill<\/strong>.<\/td>\r\nAdvantage<\/strong>: Non-invasive and\u00a0easy to administer<\/strong><\/td>\r\nOral polio vaccine (OPV), Typhoid vaccine.<\/strong><\/td>\r\n<\/tr>\r\n
            Disadvantage<\/strong>: Potential for\u00a0lower efficacy in certain cases.<\/strong><\/td>\r\n<\/tr>\r\n
            Nasal Vaccines<\/strong><\/td>\r\nAdministered as a\u00a0mist or spray into the nose.<\/strong><\/td>\r\nAdvantage:\u00a0<\/strong>Induce local\u00a0immunity in the respiratory tract.<\/strong><\/td>\r\nLive attenuated influenza vaccine.<\/strong><\/td>\r\n<\/tr>\r\n
            Disadvantage:\u00a0<\/strong>No universal application<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/figure>\r\n

            Significance of Vaccine<\/h2>\r\n

            Vaccines prevent diseases, save lives, reduce healthcare costs, protect vulnerable populations, and bolster global public health through herd immunity and disease eradication. Several advantages of vaccines are:<\/p>\r\n

              \r\n\t
            • Combatting infectious diseases<\/strong>: Vaccines stand as powerful instruments in the fight against infectious ailments.<\/strong>\r\n
                \r\n\t
              • Since the 1960s,\u00a0measles vaccinations have resulted in a 99% drop in measles\u00a0<\/strong>occurrences in the U.S.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
              • Eliminating diseases globally:\u00a0<\/strong>Comprehensive vaccination campaigns can lead to the\u00a0total eradication of specific illnesses worldwide<\/strong>. Example: declaration of\u00a0smallpox's eradication in 1980.<\/strong><\/li>\r\n\t
              • Mitigating disease impact<\/strong>: Beyond disease prevention, vaccines also\u00a0diminish the intensity and associated complications<\/strong>\u00a0for those who may still contract them.\r\n\r\n
                  \r\n\t
                • The\u00a0influenza vaccine<\/strong>\u00a0curtails the disease's harshness,\u00a0decreasing hospitalisation and mortality risks.<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                • Financial advantages<\/strong>: Disease prevention through vaccines lessens medical expenses and cuts down on economic impacts<\/strong>.\r\n\r\n
                    \r\n\t
                  • Child vaccinations in the U.S. avert\u00a0roughly $13.5 billion in direct costs.<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                  • Shielding the At-risk groups: Herd immunity<\/strong>\u00a0achieved through vaccination safeguards those unable to receive vaccines, like those with specific allergies or weakened immune defences.\r\n\r\n
                      \r\n\t
                    • Vaccinating most individuals against\u00a0pertussis (whooping cough) ensures protection for newborns not yet fully vaccinated.<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                    • Staving off disease return:\u00a0<\/strong>Persistent immunisation practices are essential\u00a0to ward off the return of diseases\u00a0<\/strong>that have become uncommon.\r\n\r\n
                        \r\n\t
                      • Global vaccination efforts have slashed polio cases by over 99% since 1988,<\/strong>\u00a0but neglecting immunisation might cause a rapid comeback.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                      • Curbing antibiotic resistance<\/strong>: By warding off bacterial diseases,\u00a0vaccines decrease antibiotic use, helping in the battle against antibiotic resistance.<\/strong>\r\n
                          \r\n\t
                        • Pneumococcal conjugate vaccine\u00a0<\/strong>has cut down occurrences of antibiotic-resistant invasive pneumococcal infections.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                        • Defence against adapting diseases:\u00a0<\/strong>Vaccine development adapts in\u00a0the face of evolving pathogens.<\/strong>\r\n
                            \r\n\t
                          • The flu vaccine is recalibrated yearly to match dominant strains, and\u00a0the rapid creation of COVID-19 vaccines is a testament to this adaptability.<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                          • Endorsement of lifelong health:\u00a0<\/strong>Certain vaccines offer\u00a0enduring defence against illnesses<\/strong>\u00a0that could lead to lasting ailments or cancers.<\/li>\r\n\t
                          • The HPV vaccine wards off the virus types causing numerous cervical cancers.<\/strong><\/li>\r\n\t
                          • Augmenting public health standards: Mass immunisation\u00a0<\/strong>uplifts the collective health of communities and\u00a0lightens the load on medical infrastructures.<\/strong>\r\n
                              \r\n\t
                            • After the launch of the rotavirus vaccine,\u00a0<\/strong>there was a marked\u00a0drop in severe diarrhoea-related hospital stays in young children.<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n

                              Challenges associated with Vaccines<\/h2>\r\n

                              Vaccines are pivotal in combating infectious diseases, yet their creation, dissemination, and public reception entail a range of complex challenges. Several challenges associated with vaccines are:<\/p>\r\n

                                \r\n\t
                              • Production and Logistic Challenges<\/strong>\r\n
                                  \r\n\t
                                • Research & Innovation:\u00a0<\/strong>Identifying safe and potent formulations demands significant time, research, and monetary resources.<\/li>\r\n\t
                                • Example:\u00a0The development of an HIV vaccine<\/strong><\/li>\r\n\t
                                • Efficacy & Safety evaluation:\u00a0<\/strong>Multi-phase clinical tests are pivotal for verifying safety and performance, though they can be protracted and costly.<\/li>\r\n\t
                                • Example:\u00a0Pause of AstraZeneca Covid Vaccines.<\/strong><\/li>\r\n\t
                                • Production expansion:\u00a0<\/strong>Shifting from laboratory settings to large-scale manufacturing while maintaining quality presents challenges.<\/li>\r\n\t
                                • Example:\u00a0Early stages of Covid-19 vaccines.<\/strong><\/li>\r\n\t
                                • Cost:\u00a0<\/strong>High costs can limit vaccine availability.\r\n\r\n
                                    \r\n\t
                                  • Example:\u00a0Pneumococcal vaccines<\/strong>\u00a0are expensive, impacting distribution in low-income countries.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                  • Supply chain:<\/strong>\u00a0Ensuring stable raw material supply is crucial.\r\n\r\n
                                      \r\n\t
                                    • Example:\u00a0Global shortage of eggs during H1N1 influenza<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                    • Cold chain management:<\/strong>\u00a0Some vaccines need specific temperature control.\r\n\r\n
                                        \r\n\t
                                      • Example:\u00a0The Pfizer-BioNTech COVID-19 vaccine<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                      • Biosafety: Handling pathogens demands safety precautions.<\/strong><\/li>\r\n\t
                                      • Accessibility Challenges<\/strong><\/li>\r\n\t
                                      • Distribution infrastructure:<\/strong>\u00a0Inadequate infrastructure can hinder vaccine delivery.\r\n\r\n
                                          \r\n\t
                                        • Example:\u00a0Remote areas<\/strong>\u00a0in countries like Chad or Afghanistan.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                        • Intellectual Property and licensing: Patent issues can restrict the production of cheaper generic versions.<\/strong><\/li>\r\n\t
                                        • Example:\u00a0HIV\/AIDS medication accessibility faced challenges until patent flexibilities allowed generic production.<\/strong><\/li>\r\n\t
                                        • Inequitable global distribution:<\/strong>\u00a0Wealthier countries may secure larger vaccine stocks, leaving\u00a0fewer doses for low-income countries.<\/strong>\r\n
                                            \r\n\t
                                          • Example: Covid-19 Vaccine distribution.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                          • Vaccine Hesitancy<\/strong>\r\n
                                              \r\n\t
                                            • Misinformation and myths:\u00a0<\/strong>Misleading information can lead to unfounded fears about vaccines.<\/li>\r\n\t
                                            • Example:\u00a0Myth about the relation between Autism and MMR vaccine.<\/strong><\/li>\r\n\t
                                            • Cultural and religious beliefs:<\/strong>\u00a0Some communities refuse vaccines based on cultural or religious principles .\r\n\r\n
                                                \r\n\t
                                              • Example:\u00a0Opposition to Polio vaccines in Pakistan<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                              • Lack of knowledge<\/strong>: Insufficient awareness about vaccine benefits and the diseases they prevent\u00a0can hinder acceptance.<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                              • Responsiveness Challenges<\/strong>\r\n
                                                  \r\n\t
                                                • Age:\u00a0<\/strong>The immune response can vary with age. Example: The influenza vaccine where the elderly, despite being vaccinated, might still be at risk due to a\u00a0diminished immune response.<\/strong><\/li>\r\n\t
                                                • Nutritional status:\u00a0<\/strong>Malnutrition can weaken the immune system and\u00a0reduce vaccine efficacy.<\/strong><\/li>\r\n\t
                                                • Genetics:<\/strong>\u00a0Genetic makeup can influence how one responds to a vaccine. Some genetic profiles might result in stronger immune responses than others.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                                • Other Challenges<\/strong>\r\n
                                                    \r\n\t
                                                  • Vaccine-induced infection:\u00a0<\/strong>It refers to the rare occurrence where a vaccine causes the very disease it's designed to prevent.<\/li>\r\n\t
                                                  • This situation is primarily a concern with live attenuated vaccines.<\/li>\r\n\t
                                                  • Example:\u00a0Oral Polio Vaccine (OPV) caused vaccine-associated paralytic poliomyelitis (VAPP) in a small number of recipients.<\/strong><\/li>\r\n\t
                                                  • Comorbidities challenges:\u00a0<\/strong>Developing vaccines for people with comorbidities is a challenging task.<\/li>\r\n\t
                                                  • Booster shots:<\/strong>\u00a0Some vaccines require multiple doses for full protection.\r\n\r\n
                                                      \r\n\t
                                                    • Example:\u00a0The HPV vaccine initially required three doses over six months.<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                                    • Duration of protection:\u00a0<\/strong>Some vaccines don't offer lifelong immunity and need boosters.\r\n\r\n
                                                        \r\n\t
                                                      • Example:\u00a0Tetanus shots are recommended every 10 years<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n

                                                        Vaccines UPSC PYQs<\/h2>\r\n

                                                        Question 1:<\/strong>\u00a0Consider the following: (UPSC Prelims 2021)<\/strong><\/p>\r\n

                                                          \r\n\t
                                                        1. Bacteria<\/li>\r\n\t
                                                        2. Fungi<\/li>\r\n\t
                                                        3. V<\/li>\r\n\t
                                                        4. irus<\/li>\r\n<\/ol>\r\n

                                                          Which of the above can be cultured in an artificial\/synthetic medium?<\/p>\r\n

                                                          (a) 1 and 2 only<\/p>\r\n

                                                          (b) 2 and 3 only<\/p>\r\n

                                                          (c) 1 and 3 only<\/p>\r\n

                                                          (d) 1, 2 and 3<\/p>\r\n

                                                          Answer: (a)<\/strong><\/p>\r\n

                                                          Question 2:<\/strong>\u00a0With reference to recent developments regarding \u2018Recombinant vector Vaccines\u2019, consider the following statements:\u00a0(UPSC Prelims 2021)<\/strong><\/p>\r\n

                                                            \r\n\t
                                                          1. Genetic engineering is applied in the development of these vaccines.<\/li>\r\n\t
                                                          2. Bacteria and viruses are used as vectors.<\/li>\r\n<\/ol>\r\n

                                                            Which of the statements given above is\/are correct?<\/p>\r\n

                                                              \r\n\t
                                                            1. 1 only<\/li>\r\n\t
                                                            2. 2 only<\/li>\r\n\t
                                                            3. Both 1 and 2<\/li>\r\n\t
                                                            4. Neither 1 nor 2<\/li>\r\n<\/ol>\r\n

                                                              Answer: (c)<\/strong><\/p>\r\n

                                                              Question 3:<\/strong>\u00a0The Human Papilloma Virus vaccine has been making the headlines in recent months. Who make the ideal candidates for receiving this vaccine and what are its benefits?\u00a0(UPSC Mains 2012)<\/strong><\/p>","protected":false},"excerpt":{"rendered":"

                                                              Vaccines stimulate immunity against diseases, providing protection without causing the disease itself, revolutionising public health and preventing countless illnesses and deaths globally.<\/p>\n","protected":false},"author":6,"featured_media":8305,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[173],"tags":[40,223],"class_list":{"0":"post-4147","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-quest-level-3","8":"tag-quest","9":"tag-vaccine"},"acf":[],"_links":{"self":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/4147","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/comments?post=4147"}],"version-history":[{"count":1,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/4147\/revisions"}],"predecessor-version":[{"id":19999,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/4147\/revisions\/19999"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media\/8305"}],"wp:attachment":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media?parent=4147"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/categories?post=4147"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/tags?post=4147"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}