19 Do you know who and why cannot be vaccinated? According to the WHO (World Health Organization) we currently have vaccines to prevent more than 20 life-threatening diseases and preventing 3.5 top 5 million deaths a year. For examples, in some parts of Africa, a vaccine against yellow fever is necessary, and so on and so forth in other countries. VACCINES Vaccines are substances used to stimulate immunity to a particular infection or pathogen and they are used as a form of prevention to guarantee protection from diseases. Some vaccines may cause more side-effects than others, and not everyone may be vaccinated , but immunisation is key to primary health care. A bit of history The father of immunology was Edward Jenner, an Englishman born in times when smallpox threatened millions of people s lives. In 1796, after having noticed that milkmaids who suffered the mild disease of cowpox never contracted smallpox, he inserted some pus taken from a cowpox pustule into an incision on a boy s arm, making him immune to smallpox. After some more tests, Jenner published his results and invented the term vaccine from the Latin vacca, cow. Types of vaccines Though their purpose is the same, there exist different types of vaccines depending on how they are created. Live-attenuated vaccines contain live pathogens from either a bacterium or a virus that have been weakened. Inactivated vaccines use a killed version of a pathogen. Subunit, recombinant, conjugate, and polysaccharide vaccines are made from a piece of the pathogen, not the whole organism. chickenpox: varicella cowpox: vaiolo del bestiame measles: morbillo milkmaid: mungitrice mumps: parotite (orecchioni) rubella: rosolia smallpox: vaiolo whooping cough: pertosse 42 BODY AND MIND There are three main approaches to making a vaccine: Using a whole virus Parts that trigger or bacterium the immune system Just the genetic material The whole-microbe approach Inactivated vaccine Live-attenuated vaccine Viral vector vaccine DNA vaccines include DNA that creates specific antigens from a pathogen: once in the body, the DNA is reproduced by the body and is recognised by the immune system. Recombinant vector vaccines act like a natural infection and train the immune system to recognise and attack pathogens. Vaccination programmes International institutions have agreed on vaccination programmes for the population, and national institutions implement and integrate them with local necessities. Most programmes include the following vaccinations: Chickenpox vaccine, Toxoid vaccines use inactivated toxins to target the toxic activity created by the bacteria. Hepatitis A, Viral vector vaccines use a harmless virus to deliver to some host cells the genetic code of the antigen that needs fighting. MMR vaccine (measles, mumps, and rubella), Messenger RNA (mRNA) vaccines teach the body how to make a type of protein like that of the virus, triggering the immune system to produce specific antibodies. Hepatitis B vaccine, Human papillomavirus vaccine, Tdap vaccine (tetanus, diphtheria, and whooping cough), Rotavirus vaccine, Pneumococcal vaccine, Meningococcal vaccine, Polio vaccine.