Lecture 10- Childhood immunisations

Question 1

Louise Pasteur

Answer 1

• Produced the first live attenuated vaccine against rabies and anthrax
• a French biologist, microbiologist, and chemist renowned for his discoveries of the principles of vaccination, microbial fermentation, and pasteurisation.
• He is remembered for his remarkable breakthroughs in the causes and prevention of diseases, and his discoveries have saved many lives ever since.
• He reduced mortality from puerperal fever and created the first vaccines for rabies and anthrax.

Question 2

Leon Calmette

Answer 2

• Léon Charles Albert Calmette (12 July 1863 – 29 October 1933) was a French physician, bacteriologist and immunologist, and an important officer of the Pasteur Institute. He discovered the Bacillus Calmette-Guérin, an attenuated form of Mycobacterium bovis used in the BCG vaccine against tuberculosis.
• He also developed the first antivenom for snake venom, the Calmette’s serum

Question 3

Facts about vaccines

Answer 3

• Vaccines provide better immunity than natural infections
• Combined vaccines are safe and beneficial e.g. MMR
• If we stop vaccination disease will return

Question 4

Value of immunisation

Answer 4

• Cost effective ways to save lives, improve health and ensure long-term prosperity
• Massive overall economic benefit e.g. the losses of money due to healthcare and loss of productivity due to illness caused by infection
• Saves 2-3 million liver each year
• Have eradicated smallpox and polio to just 3 countries in the world
• Reduces burden on healthcare system
• Not being ill means that childrens cognitive and physical skill improve quicker

Question 5

Children are one of the most

Answer 5

vulnerable groups- need to make sure vaccines work and they are safe

Question 6

Measuring effectiveness

Answer 6

• Antibodies (measurement of correlate of protection but does it measure whether the vaccine works)
• Epidemiological assessment

Question 7

Safety of vaccination

Answer 7

Safety

• Animal trials
• Human trials (prequalification)
• Post marketing surveillance (Urabe Mumps strain caused encephalitis)

Question 8

Efficacy monitoring – are the biologicals in the vaccine correct?

Answer 8

National Institute of Biological Standards and Control

Question 9

Which countries miss out from vaccines?

• Nigeria
• India
• Pakistan
• Indonesia
• etc

Question 10

JCVI – Joint Committee on Vaccination and Immunisation

Answer 10

is an independent expert advisory committee of the United Kingdom Department of Health. JCVI was established in 1963 “To advise the Secretaries of State for Health, Scotland, Wales and Northern Ireland on matters relating to communicable diseases, preventable and potentially preventable through immunisation.” The advisory body makes recommendations to the British government concerning vaccination schedules and vaccine safety.

Question 12

The Green Book ​

Answer 12

• has the latest information on vaccines and vaccination procedures, for vaccine preventable infectious diseases in the UK.

Question 13

Vaccine hesitancy

Answer 13

• Vaccine hesitancy refers to delay in acceptance or refusal of vaccines despite availability of vaccination services.
• Vaccine hesitancy is complex and context specific varying across time, place and vaccines.
• It includes factors such as complacency, convenience and confidence.

Question 14

andrew wakefield

Answer 14

• In 1998, Andrew Wakefield and 12 of his colleagues published a case series in the Lancet, which suggested that the measles, mumps, and rubella (MMR) vaccine may predispose to behavioural regression and pervasive developmental disorder in children.
• Despite the small sample size (n=12), the uncontrolled design, and the speculative nature of the conclusions, the paper received wide publicity, and MMR vaccination rates began to drop because parents were concerned about the risk of autism after vaccination.
• Almost immediately afterward, epidemiological studies were conducted and published, refuting the posited link between MMR vaccination and autism.
• The logic that the MMR vaccine may trigger autism was also questioned because a temporal link between the two is almost predestined: both events, by design (MMR vaccine) or definition (autism), occur in early childhood.
• The next episode in the saga was a short retraction of the interpretation of the original data by 10 of the 12 co-authors of the paper. According to the retraction, “no causal link was established between MMR vaccine and autism as the data were insufficient”.
• This was accompanied by an admission by the Lancet that Wakefield et al.had failed to disclose financial interests (e.g., Wakefield had been funded by lawyers who had been engaged by parents in lawsuits against vaccine-producing companies). However, the Lancet exonerated Wakefield and his colleagues from charges of ethical violations and scientific misconduct.
• The Lancet completely retracted the Wakefield et al. paper in February 2010, admitting that several elements in the paper were incorrect, contrary to the findings of the earlier investigation. Wakefield et al. were held guilty of ethical violations (they had conducted invasive investigations on the children without obtaining the necessary ethical clearances) and scientific misrepresentation (they reported that their sampling was consecutive when, in fact, it was selective). This retraction was published as a small, anonymous paragraph in the journal, on behalf of the editors.
• The final episode in the saga is the revelation that Wakefield et al. were guilty of deliberate fraud (they picked and chose data that suited their case; they falsified facts).
• The British Medical Journal has published a series of articles on the exposure of the fraud, which appears to have taken place for financial gain. It is a matter of concern that the exposé was a result of journalistic investigation, rather than academic vigilance followed by the institution of corrective measures. Readers may be interested to learn that the journalist on the Wakefield case, Brian Deer, had earlier reported on the false implication of thiomersal (in vaccines) in the etiology of autism.