vaccines

What are the estimated annual deaths worldwide caused by infectious diseases?

Over 10 million people a year worldwide.

What percentage of Ireland's population is killed by infectious diseases annually?

Approximately 5,000 people in Ireland each year (~1% of the population).

What two factors can prevent most deaths caused by infectious diseases?

Vaccines and proper sanitation (clean water and sewage systems).

What molecular changes occur when microorganisms like influenza and Sars-CoV2 mutate, reducing immunity?

The DNA of the microorganism changes, which leads to the proteins changing.

What type of cancer-causing infection is mentioned in the sources?

HPV, which causes cancers of the anus and cervix.

What is the virus responsible for smallpox?

Variola virus (major vs minor), which is part of the Pox family of viruses.

What is the $R_0$ (basic reproduction number) for smallpox?

3-6.

When and where were the first recorded cases of smallpox found?

In ancient Egypt on mummies around 1500 BC.

What was the approximate mortality rate associated with smallpox infection?

Approximately 30% mortality.

What were common causes of death from smallpox?

Organ failure, pneumonia, and CVS collapse.

When did viruses become visible using technology?

Not until the 1930s with the electron microscope (EM).

What is variolation?

The disease is scraped onto someone, which leads them to being less infectious.

Where and since when has variolation been practiced?

In China and Asia since the 1500s.

Who brought the technique of variolation to England and when?

Lady Mary Wortley Montagu in 1721.

What is the origin of the word "vaccine"?

It comes from the Cowpox Vaccinia virus, as "Vacca" means cow.

Who is credited with the 1796 vaccination discovery using cowpox?

Edward Jenner.

Who was the 8-year-old child inoculated by Edward Jenner in 1796?

James Phipps.

When was smallpox declared eradicated?

1980.

What is the $R_0$ for Measles?

12-18.

What is the $R_0$ for Influenza?

1-2.

What was the approximate $R_0$ for early COVID-19?

5-7.

What are the causes of death from Measles?

Pneumonia and/or encephalitis (brain swelling).

What type of vaccine is the measles, mumps, rubella vaccination (MMR)?

A live attenuated vaccine.

How does the Polio virus spread?

Via the faecal-oral route through contaminated water, food, and unclean hands.

What is the $R_0$ for Polio?

5-7.

How does Polio cause death?

The breathing system loses function.

At its peak (1950s), how many people did Polio paralyze or kill annually?

500,000 people a year.

When was Salk’s Inactivated Polio Vaccine introduced?

1955.

When was Sabin’s Oral Polio Vaccine introduced?

1960.

According to a study covering 1974 to 2024, how many total deaths were saved by childhood vaccines?

154 million total.

Between 1974 and 2024, how many measles deaths were saved by childhood vaccines?

93.7 million.

Between 1974 and 2024, how many tetanus deaths were saved by childhood vaccines?

27.9 million.

What are the local physical experiences when receiving a vaccine?

Raised skin (leaked capillary fluid), redness (increase of blood flow), and soreness (nerve endings more sensitive).

How do vaccines allow the body to create antibodies?

The vaccine allows the body to make b cells; antibodies of all different shapes are created to ensure that one is correct and will bind to the antigen.

What cells copy the correct antibody to fight an infection after a vaccine is administered?

Plasma cells.

What minimum percentage of population immunity is generally needed for Herd Immunity?

A minimum of 60-70% (but this figure depends on the $R_0$).

What is passive immunization?

Antibodies against a specific infectious organism are given directly to a person.

How long does passive immunization typically last?

Only a few days or weeks until the body eliminates the injected antibodies.

What is reactogenicity?

Local inflammation at the injection site that can lead to pain, swelling, and redness.

What systemic responses can reactogenicity cause?

Fever, chills, and myalgia (muscle aches & pains), depending on the production of cytokines.

What are 'vaccine associated enhancement of diseases'?

An antibody dependent enhancement due to cellular uptake and deposition in certain tissues, such as seen with Dengue virus.

What issue arose from production/batch errors, citing the example of Cutter Labs and Polio?

Variation in batches of vaccines caused different side effects depending on the contaminant.

Who published a retracted report in 1998 linking the MMR vaccine to colonic inflammation and autism?

Andrew Wakefield.

What consequence followed the increasing vaccine skepticism after the Wakefield incident?

Measles cases started to increase.

Why is vaccine skepticism currently increasing and vaccine uptake decreasing?

Social media news use means vaccine skepticism is increasing, especially in the past 5 years.

When was the virus SARS-CoV2, causing lethal pneumonia (COVID-19), identified?

December 2019 in Wuhan, China.

How many worldwide deaths has COVID-19 caused?

Over 7 million deaths worldwide.

How quickly were COVID-19 vaccines developed and approved?

In a record time of approximately 11 months.

What efficacy did the initial COVID-19 vaccines have, and what new platforms were used?

95% efficacy using never used before mRNA and viral platforms.

What protections did the COVID-19 vaccines provide?

Protection against serious illness, hospitalization, and deaths.

Historically, why were pandemics rare?

Limited travel, rural living, and limited interactions of people meant limited transmission.

What modern factors have increased the prevalence of pandemics?

Increased populations, high density cities, globalization, travel, and zoonosis.

For which three major diseases are more effective or new vaccines still needed?

TB, malaria, and HIV.

What is the combined annual global death toll from TB, malaria, and HIV?

2.5 million deaths a year worldwide.

What is the fundamental role of vaccines in the immune system?

Vaccines train the immune system to recognise a part/component of a microorganism and they significantly reduce the risk of severe disease in people.

Which disease was the first to have a successful vaccine and was subsequently eradicated?

Smallpox.