Vaccinations - SOSC 1801

Historical Context:
- 18th Century England faced rampant smallpox infections, a highly lethal disease.
- Estimated death toll of smallpox was 10-30% of all burials.
- Caused by the orthopox virus, variola (VARV).
- Transmitted mainly person-to-person; survivors developed lifelong immunity.
Disease Dynamics:
- Smallpox described as a crowd disease, requiring a large population of susceptible hosts.
- Historian William McNeill noted that population growth and migration increased disease frequency and host accumulation.
- Continued epidemics led to fewer individuals escaping infection and greater childhood immunity.

Variolation:
- A primitive vaccination method where healthy individuals were infected with material from mildly affected patients.
- Originated in China and India, but mortality and infection transmission risks existed.
Discovery of Cowpox Immunity:
- Jenner observed that individuals with cowpox immunity did not contract smallpox, whether accidentally or intentionally exposed.

May 1796:
- Jenner found dairymaid Sarah Nelmes with cowpox lesions.
- He inoculated 8-year-old James Phipps with matter from her lesions.
- Phipps experienced mild illness but fully recovered.
Smallpox Challenge:
- Jenner inoculated Phipps again with smallpox matter on July 1, 1796.
- Phipps showed no symptoms, indicating complete protection.
Impact on Public Health:
- In 1798, Jenner published "An Inquiry into the Causes and Effects of the Variolae Vaccinae."
- Established the first free vaccination clinic at his home, prioritizing need over ability to pay.
- This clinic symbolized hope and the emerging values of a public health system.

1885: Dr. Alexander Stewart founded a vaccine farm in Ontario, supplying smallpox vaccine for 31 years.
1918: Introduction of Canada's first pertussis vaccine.
1924: 9,000 diphtheria cases reported; a leading cause of child mortality.
1926: Diphtheria toxoid introduced for protection.
1940: Tetanus toxoid introduced in Canada.
1943: Routine immunization against pertussis approved.
1953: Polio epidemic occurred with 9,000 reported cases; vaccine drastically reduced this.
1955: Salk polio vaccine licensed in North America.

1963: First measles vaccine approved, previously having over 300,000 cases annually.
1964: Formation of the National Advisory Committee on Immunizing Agents (now NACI).
1969: Introduction of rubella vaccine; reduced incidence significantly.
1972: Routine smallpox vaccination ceased.
1977: Last indigenous smallpox case recorded in Somalia.
1982: Hepatitis B vaccine introduced; school programs began in 1987.
1983: MMR immunization program initiated, drastically reducing rubella cases.
1994: Canada declared polio-free.
1995: Switch from OPV to IPV to prevent vaccine-associated paralytic poliomyelitis (VAPP).
2004: Inactivated influenza vaccine recommended for young children.
2006: Approval of the first HPV vaccine for cervical cancer prevention.

Polio Overview:
- Poliomyelitis is an acute viral disease affecting the nervous system, primarily children under 5.
- Mid-20th century polio caused hundreds of thousands of cases annually with no cure available.
Impact of Vaccination:
- Widespread use of vaccines since the 1960s led to polio elimination in most areas.
- Currently endemic in only three countries: Afghanistan, Pakistan, and Nigeria.
- Reported polio cases have dropped by more than 99% worldwide since 1988.

Immunity: Protection against infectious diseases; can be acquired naturally or through vaccination.
Vaccine: A product that triggers immunity to a specific disease, typically given by injection, orally, or nasally.
Vaccination: The act of administering a vaccine to confer immunity.
Immunization: A process making a person immune, often synonymous with vaccination.
mRNA Vaccines: A new vaccine type teaching cells to produce proteins that provoke an immune response.

Public Acceptance:
- Over 80% acceptance of vaccines worldwide (WHO, 2012).
- Increasing parental refusal or delay of vaccines raises concerns over vaccine-preventable diseases.
Reasons for Hesitancy:
- Religious objections, personal beliefs, safety concerns, and a desire for more information from healthcare providers.

Ethical dilemmas: Concerns about human or animal tissues in vaccine production (e.g., human tissues from aborted fetuses in rubella vaccines).
Spiritual beliefs: Some believe illness is divine and should be approached with faith rather than medicine.
Crusading agenda theories: In regions like Nigeria and Afghanistan, skepticism arises from perceived links to ulterior motives in vaccination efforts.

Natural Immunity: Some parents believe that natural infections are more beneficial than vaccination-induced immunity.
Perceived Risks: Concerns about the vaccines’ side effects versus the perceived insignificance of preventable diseases.
Healthy Lifestyle Assumptions: Some believe that a healthy lifestyle decreases the need for vaccinations.

Media Influence: Many safety concerns arise from media reports, leading to doubts about short and long-term vaccine effects.
Specific Fears: Instances like HPV vaccine links to infertility and MMR’s alleged connection to autism
Government Interventions: The introduction of the Vaccine Injury Support Program in response to public concerns about vaccine safety.

Information Gaps: Parents often report wanting more accessible and balanced information about vaccination risks and benefits.
Access to Experts: Findings show one-third of parents feel they lack sufficient provider communication regarding vaccines.
Demand for Factual Sharing: Parents express the desire for straightforward, factual content about vaccines, aiming to facilitate informed decisions on childhood healthcare.