History of vaccine development

You can read more about the state of the world’s vaccines and immunization on this WHO page:

Immunization Analysis and Insights

Although inoculationInoculationThe practice of intentionally exposing someone to matter from smallpox pustules in order to initiate a mild, protective response to the disease. against smallpox was practiced over 2000 years ago in China and India, a British physician, Edward Jenner, is generally credited with ushering in the modern concept of vaccination. In 1796 he used matter from cowpox pustules to inoculate patients successfully against smallpox, which is caused by a related virusVirusAn ultramicroscopic infectious agent that consists of genetic material surrounded by a protein coat. A virus can replicate themselves only within cells of living hosts..

By 1900, there were two human virus vaccines, against smallpox and rabiesRabiesA potentially fatal viral infection spread through the bite of certain warm-blooded animals. It attacks the central nervous system and, if left untreated, is highly fatal in animals., and three bacterial vaccines against typhoidTyphoid (typhoid fever)A serious disease caused by a bacteria called Salmonella Typhi. Typhoid causes a high fever, weakness, stomach pains, headache, loss of appetite, and sometimes a rash. If it is not treated, it can kill up to 30% of people who get it. There are different vaccines to prevent typhoid: inactivated vaccines that require injection, and live attenuated vaccines that are taken orally (by mouth)., choleraCholeraAn acute infectious disease of the small intestine, caused by the bacterium Vibrio cholerae and characterized by profuse watery diarrhea, vomiting, muscle cramps, severe dehydration, and depletion of electrolytes., and plaguePlagueA serious, potentially life-threatening infectious disease that is usually transmitted to humans by the bites of rodent fleas. It was one of the scourges of early human history..

A worldwide case detection and vaccination programme against smallpox gathered pace and, in 1979, the World Health Assembly officially declared smallpox eradicated — a feat that remains one of history's greatest public health triumphs.

Question

Smallpox was declared eradicated in 1979. Can you tell the difference between eradication and elimination of a disease? Select the two correct definitions for eradication and elimination of a disease:

A. Eradication refers to the complete and permanent worldwide reduction to zero new cases of the disease through deliberate efforts.
B. Eradication refers to the reduction to zero (or a very low defined target rate) of new cases in a defined geographical area.
C. Elimination refers to the complete and permanent worldwide reduction to zero new cases of the disease through deliberate efforts.
D. Elimination refers to the reduction to zero (or a very low defined target rate) of new cases in a defined geographical area.

Answer

Answer A and D are correct.

EradicationEradicationThe complete and permanent worldwide reduction to zero new cases of an infectious disease through deliberate efforts; no further control measures are required. refers to the complete and permanent worldwide reduction to zero new cases of the disease through deliberate efforts.

  • If a disease has been eradicated, no further control measures are required.

EliminationEliminationReduction to zero (or a very low defined target rate) of new cases of an infectious disease in a defined geographical area as a result of deliberate efforts; continued measures to prevent re-establishment of transmission are required. refers to the reduction to zero (or a very low defined target rate) of new cases in a defined geographical area.

  • Elimination requires continued measures to prevent re-establishment of disease transmission.
Regulatory and safety issues of vaccines before and after licenses are granted are discussed later in this module

Based on the emerging success of the smallpox programme, in 1974, the World Health Organization (WHO) launched the Expanded Programme on Immunization (EPI). The initial EPI goals were to ensure that every child received protection against six childhood diseases (i.e. tuberculosisTuberculosis (TB) A disease caused by the bacterium Mycobacterium tuberculosis. The bacteria usually attack the lungs. But, TB bacteria can attack any part of the body such as the kidney, spine, and brain. If not treated properly, TB disease can be fatal., polio, diphtheria, pertussis, tetanus and measles) by the time they were one year of age and to give tetanus toxoid vaccinationsTetanus toxoid (TT) vaccine A preparation of tetanus toxoid used to immunize against tetanus. When given to women of childbearing age, vaccines that contain tetanus toxoid (TT or Td) not only protect women against tetanus, but also prevent neonatal tetanus in their newborn infants. to women to protect them and their newborns against tetanus.

Since then, new vaccines have become available. Some of them, such as hepatitis BHepatitis B A viral infection of the liver that is transmitted through contact with blood or other body fluids that are infected with the hepatitis B virus. Some infections, especially those acquired in infancy, can become chronic and result in cirrhosis and primary liver cancer in adulthood., rotavirusRotavirus A group of viruses that cause diarrhea (rotaviral gastroenteritis) in children., Haemophilus influenzae type b (Hib)Haemophilus influenzae type b (Hib) Bacteria that can cause serious invasive illnesses, such as pneumonia and meningitis; most common in children and persons who are immune compromised (less able to fight off infections). Hib is one of six types of bacteria that are major causes of bacterial meningitis in unimmunized infants. and pneumococcal vaccines, Human Papillomavirus vaccine, are recommended by the WHO for global use. Others, such as yellow feverYellow fever An infectious viral tropical disease transmitted by mosquitoes and characterized by high fever, jaundice, and gastrointestinal bleeding. vaccine, Typhoid conjugate vaccine, Ebola vaccine are recommended in countries where disease burden data indicate they should be used.

By 1990, vaccination was protecting over 80% of the world's children from the six main EPI diseases, and other new vaccines are continually being added to the EPI programmes in many countries.

In 2000, the Global Alliance for Vaccines and Immunization (GAVI) was created to bringing together public and private sectors with the shared goal of creating equal access to new and underused vaccines for children living in the world’s poorest countries.

The Global Vaccine Action Plan (GVAP) – endorsed by the 194 Member States of the World Health Assembly in May 2012 – was a framework to prevent millions of deaths by 2020 through more equitable access to existing vaccines for people in all communities. GVAP was the product of the Decade of Vaccine Collaboration, an unprecedented effort that brought together development, health and immunization experts and stakeholders.

In May 2017, the new resolution on strengthening immunization was endorsed by the ministries of health from 194 countries. The resolution urges countries to strengthen the governance and leadership of national immunization programmes, and improve monitoring and surveillance systems to ensure up-to-date data guides policy and programmatic decisions to optimize performance and impact. It also calls on countries to expand immunization services beyond infancy, mobilize domestic financing, and strengthen international cooperation to achieve GVAP goals.

In 2020, WHO is leading the creation of the Immunization Agenda 2020 (IA2020), to address the challenges related to vaccines over the next decade. The IA 2030 strategy – to extend the benefits of vaccines to everyone, everywhere – is underpinned by four core principles:it puts people in the center, it is led by countries, it is implemented through broad partnerships, and it is driven by data.

Strengthening immunization

1974

WHO launches EPI


Goals:
  • Very child (< 1 year) receives protection against six childhood diseases:
    – tuberculosis      – pertussis
    – polio                  – tetanus
    – diphtheria          – measles
  • Tetanus toxoid vaccinations protect women and their newborns
1990

Vaccination protects >80% of world’s children from six main EPI diseases

  • New vaccines are continually being added to the EPI programmes in many countries
2000

Global Alliance for Vaccines and Immunization (GAVI)

  • Extends reach of EPI
  • Helps poorest countries introduce new vaccines in national programmes
2011

WHO launches GVAP


Goal:
  • Deliver universal access to immunization
2017

194 countries endorse the new resolution on strengthening immunization:

  • Reinforce national immunization pogrammes
  • Expand immunization beyond infancy
  • Mobilize domestic financing
2018

116 million children completed vaccination
19.4 million children are not fully vaccinated with DTP3

In 2018, about 86% of infants worldwide (116.3 million) received 3 doses of diphtheria-tetanus-pertussis (DTP3) vaccine, protecting them against infectious diseases that can cause serious illness and disability or be fatal, leaving 19.4 million children vulnerable to vaccine preventable diseases. By 2018, 129 countries had reached at least 90% coverage of DTP3 vaccine. While immunization is probably the most successful public health intervention, reaching 86% of infants is not enough. The upward trend in coverage has increased by only 5% in the past decade and has plateaued.3

Global annual reported incidence of tetanus, diphtheria and polio and immunization coverage between 1980–20175

Source: WHO-UNICEF Immunisation coverage estimates

Global annual reported incidence of measles and pertussis and immunization coverage between 1980–20175

Source: WHO-UNICEF Immunisation coverage estimates