Adriana Castillo
Jonathan Peñaranda
Laura Barajas
VACCINES
What is a Vaccine?
A vaccine is a biological preparation that provides active acquired immunity to a
particular infectious disease. A vaccine typically contains an agent that resembles a
disease-causing microorganism. The agent stimulates the body's immune system to
recognize the agent as a threat, destroy it, and to further recognize and destroy any
of the microorganisms associated with that agent that it may encounter in the future.
The administration of vaccines is called vaccination.
When did the vaccines appear?
The terms vaccine and vaccination are derived from Variolae vaccinae (smallpox of
the cow), the term devised by Edward Jenner in 1798 (who both developed the
concept of vaccines and created the first vaccine) to denote cowpox. In 1881, to
honor Jenner, Louis Pasteur proposed that the terms should be extended to cover
the new protective inoculations then being developed.
Types of vaccines
1. Inactivated
2. Attenuated
3. Toxoid
4. Subunit
5. Conjugate
6. Experimental
Why are vaccines important?
Since vaccines were invented, the number of people who get sick or die from
infectious diseases has dropped significantly.
We now have vaccines to prevent more than 20 life-threatening diseases, helping
people of all ages live longer, healthier lives. Immunization currently prevents 2-3
million deaths every year from diseases like smallpox, poliomyelities, yellow fever,
hepatitis B, etc. Diseases like smallpox have totally disappeared.
A natural infection can provide better immunity than vaccination, but there are
serious risks. For example, a natural chickenpox infection (chickenpox) could lead to
pneumonia. A natural polio infection could cause permanent paralysis.
Vaccines not only protect you, they protect the people around you. That means that
even people who can't get vaccinated, such as those with weak or faulty immune
systems, will have some protection against the disease.
Why do some people refuse vaccination?
There are limitations to its effectiveness.
Sometimes protection fails due to vaccine-related failures or host-related failures due
to the host's immune system.
The difficulty of reaching all children, as well as cultural misunderstandings, have
caused the planned eradication date to be missed several times, because they
thought that vaccination was not clean or because they felt that it infringed on their
freedom of choice.
In 1998, physician Andrew Wakefield published a report establishing false links
between autism and intestinal diseases with the MMR vaccine (measles, mumps,
and rubella).
HOW DO YOU GET VACCINE?
Infectious agents spread easily and the majority of the world's population is still
vulnerable to it. A vaccine would provide some protection by training people's
immune systems to fight the virus so they should not become sick.This would allow
lockdowns to be lifted more safely, and social distancing to be relaxed.
Preclinical Testing: Scientists test a new vaccine on cells and then give it
to animals such as mice or monkeys to see if it produces an immune response.
Phase 1 - Safety Trials: Scientists give the vaccine to a small number of people to
test safety and dosage as well as to confirm that it stimulates the immune system.
Phase 2 - Expanded Trials: Scientists give the vaccine to hundreds of people split
into groups, such as children and the elderly, to see if the vaccine acts differently in
them. These trials further test the vaccine’s safety and ability to stimulate the
immune system.
Phase 3 - Efficacy Trials: Scientists give the vaccine to thousands of people and
wait to see how many become infected, compared with volunteers who received a
placebo. These trials can determine if the vaccine protects against the coronavirus
How many people need to be vaccinated?
It is hard to know without knowing how effective the vaccine is going to be.It is
thought that 60-70% of people needed to be immune to the virus in order to stop it
spreading easily (known as herd immunity).But that would be billions of people
around the world even if the vaccine worked perfectly.
Would a vaccine protect people of all ages?
It will, almost inevitably, be less successful in older people, because aged immune
systems do not respond as well to immunisation. We see this with the annual flu jab.
It may be possible to overcome this by either giving multiple doses or giving it
alongside a chemical (called an adjuvant) that gives the immune system a boost.
ACTIVITY
Let's expose the theme based on a PowerPoint presentation and then we're going to
do an interactive game with questions about vaccines. We will have the roulette
game.
Questions:
1. If you had children, would you
vaccinate them? Why?
2. If the Covid-19 vaccine was available,
would you want to be vaccinated?
3. Do you know of anyone how he had
an infection because they weren't
vaccinated?
4. Do you think it would be better if
vaccines didn't exist?
5. What do you think about schools
requiring children to be vaccinated?
6. Did you receive any vaccine?
7. Do you have your up-to-date vaccine
schedule?
