Former Student
School of Life Sciences
Independent University, Bangladesh
April 23, 2018
The idea behind vaccines originated
in China during the 10th century. The Chinese prevented smallpox by
blowing powdered smallpox scabs through the nostrils, i.e., literally breathing
in the smallpox virus through the nose. It was Edward Jenner in the 17th
century that popularized such peculiar ways of inoculation in Britain. He
observed how milkmaids never contracted smallpox, because they were previously
infected with cowpox. Curious, he took cowpox pus from a milkmaid and scratched
it onto a young boy. A few weeks later, he inoculated the boy with smallpox and
observed that the boy did not get smallpox. He introduced the term “vaccine”.
Vaccines began to enter the
mainstream after Louis Pasteur created vaccines for chicken cholera and anthrax
during the 18th century. Laws on compulsory vaccination began to get
established. Vaccines against diphtheria, measles, mumps and rubella became
revolutionary. Discovery of polio vaccine in the 1950s and eradication of
smallpox were major accomplishments in medical science. Till now, vaccines
remain one of the most heavily-researched and thoroughly debated topic among
scientists worldwide.
Currently Used Vaccines
Until 15 months after a baby is
born, a number of vaccines are recommended, even compulsory in many countries.
The list includes vaccines against hepatitis B, BCG, rotavirus, diphtheria,
tetanus, pertussis, influenza, polio, measles, mumps, rubella, varicella,
hepatitis A, pneumococcal conjugate and polysaccharide, meningococcus and human
papilloma virus. Many of these vaccines are followed up in later years, until
18 years of age. Unfortunately, there have been many vocal concerns from
parents about the dangers of vaccination in recent years.
The Science Behind Vaccines
Vaccines might sound scary, but
they are a proven way of protecting us against some very horrible diseases. So
what exactly are vaccines made of. Some vaccines may be preparations of
micro-organisms that were once active but have been killed or inactivated. Some
vaccines may contain live, virulent particles that have been weakened to be
safe. Still others contain deactivated toxic compounds derived from organisms,
which are the main causes of disease rather than the organisms themselves. One
recent innovation is the protein subunit vaccine against human papilloma virus
which contains the viral capsid without the genome inside. One might wonder,
why inject such harmful substances in our body? Wouldn’t it cause more harm
rather than do good? Actually, it is quite the contrary.
When viruses or bacteria enter the
human body, the immune system responds by identifying the virus or bacteria as “foreign”.
Parts that are specifically recognized and subsequently targeted as markers of
infection are called antigens. During the first encounter with a pathogen, it
takes a while for the specific immune response to develop (four to seven days)
and produce antibodies to target the antigens. By this time, many pathogens can
cause disease. However, if the host is able to survive, and the immune system
is able to mount an immune response and produce antibodies to control the infection,
it also retains memory of the antigen and the response. This means that the
next time the antigen attacks, the immune system is prepared to immediately
take it on. Vaccines work by deceiving the immune system into mounting an immune
response against specific antigens, so that during infection by the real pathogens
carrying those antigens, the host is ready. But the vaccines themselves do not
cause disease as they are dead or weakened forms of the pathogens.
How Vaccines Came to Be Considered As
Harmful
Worryingly, a very small but increasingly
significant number of the population believe and depict vaccines to be harmful.
They argue that vaccines may be responsible for conditions like autism or argue
that there has not been enough research done to ensure vaccines are completely
safe. However, these are not well-researched opinions, since decades of medical
research has indeed shown vaccines to be completely safe. The anti-vaccination
movement can be traced back to a 1998 study that showed a link between the MMR
(Measles, Mumps, Rubella) vaccine and autism. The study has since been
discredited and retracted from its journal of publication for containing fabricated
data, but the author Andrew Wakefield continues to fan the flames it set off.
In addition to the autism scare, some parents are concerned about how large pharma
companies and public health organizations earn huge profits by selling
vaccines, that are shown to be effective, but are actually not. They also feel
that vaccines are expensive and too numerous. None of this is based on fact.
A Vaccine Awareness Poster
Not vaccinating? Think Again
Parents make decisions for their
children, keeping in mind their healthy and safe future. However, what if some
of these choices end up endangering their lives, the very thing they wanted to
protect their children from? The MMR vaccine scare has had real consequences. Measles
is coming back around the world from the verge of eradication. A study that
looked at the incidence of measles in the US between 2000 and 2015 showed that
it has doubled in this time span, although the overall incidence is still quite
low (so far). There have been more outbreaks of more than 20 after 2010,
suggesting a rising trend. People have also evidently forgotten the harsh realities
of diseases such as measles and whooping cough, leading them to downplay the risk.
In an important act of science communication and creating public awareness,
this was addressed in an episode of the famous medical drama, House MD.
Dr. House comes across a teenaged
patient who has been experiencing double vision, sleeplessness, and night
terrors. After going through and eliminating several possibilities, including PTSD
(from sexual abuse, for instance), and concussion, Dr. House is initially
stumped. He observes the patient’s leg is exhibiting a myoclonic jerk, which occurs
due to sudden muscle contractions. Dr. House gets even more intrigued after results
from MRI showed a blockage in the corpus collosum of the brain due to excess
cerebrospinal fluid (CSF). As the condition progresses, the patient starts to
have auditory hallucinations and violent shaking. After much drama, Dr. House
realizes that the patient’s biological mother had not been vaccinated. She had also never had measles. During the first
few months of a child’s life, the child relies on anti-measles antibodies that
it gets from the mother during breastfeeding as the MMR vaccine is administered
at nine months. In this case, since the unvaccinated mother left the patient
vulnerable, and the observed symptoms match up a rare (1 in 100,000 cases) form
of persistent measles: sub-acute sclerosing pan-encephalitis. This is an
extremely rare consequence of persistent measles infection (1 in 10,000
thousand cases of measles). The virus hid inside the patient’s brain and ultimately led to severe inflammation there,
resulting in the symptoms describe
If the biological mother had been
vaccinated, none of this would happen. Vaccines are not as expensive, if
long-term thought is given. The patient, fictional but relevant, required
various tests, including MRI scans, and two surgeries, which are individually
and collectively far more expensive compared to vaccines. Many argue about
pharmaceuticals and public health organizations profiting vastly from vaccines
which might not be even as effective as they advertise to be. However, a 2015
statistics report showed that the top 20 pharmaceutical drugs with the biggest profit
were not even vaccines. If what they sold were not effective, and if years of
research and history were wrong about vaccines, there would have been large
epidemics of preventable diseases by now. But that is not the case. During the
1950s, 3-4 million people in the USA got measles. Vaccination until now has
reduced chances of measles by 95%. Similar decreases have been seen for
numerous other diseases such as polio, whooping cough, diphtheria, and tetanus.
By accusing vaccines of causing autism, birth defects and other conditions
without solid statistical proof, parents are depriving children from their
ability to fight diseases that have been prevented by millions of people in
this century. France points us toward a possible solution: it is a criminal
offence there for a parent to not vaccine children.
The Future of Vaccines
Research on vaccines is still at
large, as there are no established vaccines for HIV, hepatitis C, Ebola,
respiratory syncytial virus, cytomegalovirus and malaria, although there are many
experimental candidates, and there have been several trials. Several new
approaches to vaccinations are being tested. For instance, DNA vaccines, which have
been in the works for several years, use the concept of inserting
viral/bacterial DNA into the body for the DNA to be expressed as proteins in host
cells, and the immune system to then respond to them as antigens. But continued
progress relies on public funding which in turn ultimately depends on public
opinion. Therefore, for preventing preventable diseases, and generating novel
vaccines against emerging pathogens, the importance of vaccines cannot be
overstated.
Sharmeen is a recent Biochemistry graduate from IUB. She loves to explore the real world and her inner
self through science and logic.
No comments:
Post a Comment