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V For Vaccines

Before jumping into the raging debate over vaccination, here’s the A-Z of what you really need to know about it.

by / Published: 4 Sep 2017

V For Vaccines
Photo: iStock

A is for antibody. Antibodies fight invading bacteria or viruses, known as antigens, and protect you from further infection. Vaccines stimulate the antibody response without causing the actual infection, which means that your body learns to recognise the antigen without the side effects. Next time the antigen gets in; the antibody response will be quicker and can suppress it much more easily.

B is for booster shots. Certain types of vaccines may require booster shots to ‘refresh’ your immunological memory, which refers to how fast your immune system can ‘remember’ and respond to a pathogen. If a disease can spread quickly and it’s been some time since the last vaccination, it might progress faster than your immune system can react, so booster shots minimise this risk.

C is for cervical cancer. Cervical cancer is almost universally caused by the human papillomavirus (HPV), with types 16 and 18 responsible for nearly two-thirds of all cases. It can be fatal, but is preventable with the help of vaccination (Gardasil, Cervarix) that protects against two, four or nine types of HPV.

D is for diabetes. People who have diabetes, HIV, cancer or other conditions will usually be considered immunocompromised, which is when their immune system is too weak to effectively fight infections. Such people may need booster shots more frequently or may not be suitable to receive some vaccines due to a higher risk of adverse effects or reduced response.

E is for eradicated. When a disease is declared eradicated, that means infectious cases have been permanently reduced to zero. Smallpox was the first disease to be eradicated by purposeful intervention, while rinderpest (which infects mainly cattle) followed suit in 2010. In both cases, vaccination was considered to have played a crucial role in their eradication.

F is for formaldehyde. It is used to inactivate viruses and detoxify toxins from bacteria in a vaccine. There is controversy over its use in vaccines as excessive exposure might cause cancer, but the amount of formaldehyde used is less than what our bodies naturally produce and does not pose a health risk. 

G is for Guillain-Barré syndrome (GBS). This rare autoimmune disorder sees the immune system attacking the peripheral nervous system, causing muscle weakness and sometimes paralysis. It was said that people who received the 1976 swine influenza vaccine had a slightly increased risk of developing GBS, but the reason is still a mystery. There is no proven link between GBS and other flu vaccinations.

H is for herd immunity. When most people are immunised against a disease, the chances of an outbreak are reduced as it has little chance to spread. This gives some protection to those who can’t get some vaccines, such as infants, pregnant women or immunocompromised individuals. However, as immunisation rates fall, so does the herd immunity effect and they become more vulnerable.

I is for influenza. Commonly called the ‘flu’, it has two strains and differs from the common cold even though it may have similar symptoms like a cough, sore throat, runny nose and more. It is airborne and highly contagious, potentially resulting in pneumonia, inflammatory responses of the body and even death if complications arise. Because the virus mutates so quickly, a yearly booster shot is needed.

J is for Japanese Encephalitis (JE). It is a primary cause of viral encephalitis (an acute inflammation of the brain) in Asia and is borne by mosquitoes. Most infections are mild and either show no symptoms or cause a fever and headache, but severe cases can cause seizures, spastic paralysis and death. It tends to mainly affect children and has no cure, but is a vaccine-preventable disease.

K is for killed vaccines. These contain pathogens that have been killed, while live vaccines have live but weakened pathogens. Killed vaccines produce a weaker immune response and may require multiple boosters, but may be more suitable for people for which live vaccines are more risky.

L is for lymphocytes. Lymphocytes are defensive white blood cells; B-lymphocytes produce antibodies and T-lymphocytes attack infected cells in the body. Vaccines cause the immune system to produce T-lymphocytes and antibodies. After the ‘fake’ infection is over, a few T-lymphocytes are left to become ‘memory’ cells, remembering how to fight the disease if it comes back.

M is for mandatory. Some countries such as Italy and France have made certain types of vaccination mandatory after a resurgence of vaccine-preventable diseases like measles. Vaccination is not mandatory in Malaysia.

N is for natural immunity. While contracting an infection and getting over it naturally results in better immunity than vaccines, the possible complications such as birth defects, pneumonia or even death may be too high a price to pay. Vaccines, on the other hand, give you protection without the danger.

O is for overloading. Multiple vaccines delivered at once will not ‘overload’ a child’s immune system; all of a child’s required vaccines contain less than 160 immunological components, nothing compared to the thousands of germs their immune system handles daily. However, it may not be strong enough to handle tough diseases like measles, which is why vaccination is important.

P is for patch. Vaccines usually come in injection form, but a new microneedle patch has been developed to deliver an influenza vaccine. The patch has 100 water-soluble needles just long enough to penetrate the skin and can be peeled away and discarded after. It is said to be just as effective, yet painless.

Q is for quality control. Vaccines are stringently tested and controlled by local and international authorities such as the World Health Organization and the US Food and Drug Administration, even after they have been approved for the public to use.

R is for reaction. It is common to experience some minor side effects after getting a vaccine, such as a sore arm, headache, low fever or fatigue. In very rare situations, people may experience severe allergic reactions to a vaccine, but this chance is less than one in a million.

S is for schedule. Many vaccines only provide immunisation through multiple doses, so doctors have produced an immunisation schedule for maximum effectiveness. It is important to follow the schedule as missing a dose may result in ineffective immunisation and you will have to start again.

T is for travel. Countries often have different vaccination requirements or recommendations – for instance, getting a meningitis vaccine booster shot may be advisable if travelling to a country in the African meningitis belt. Your doctor will be able to recommend what, if any, you should get.

U is for uptake. Falling vaccine uptake rates in the last few years are usually attributed to Wakefield’s study that linked MMR vaccine to autism. Though later discredited, that, coupled with irresponsible social media sharing of false facts and low vaccination awareness, caused a growing anti-vaccination movement and a resurgence of vaccine-preventable diseases.

V is for vaccine-preventable diseases. The World Health Organization currently lists 25 vaccine-preventable diseases, including diphtheria, tetanus, whooping cough, polio, measles, mumps, rubella, typhoid fever, tuberculosis, yellow fever, shingles and more.

W is for Wakefield. Dr Andrew Wakefield and 12 colleagues published a case series in 1998, suggesting a link between the measles, mumps and rubella (MMR) vaccine and autism. Later, it was found that Wakefield had deliberately manipulated the data and study for financial gain. Ten of the authors retracted their interpretations, the paper was retracted and Wakefield was banned from practising medicine in the UK. There have been no other confirmed links between MMR and autism.

X is for serogroup X. It is one of 13 clinically significant serogroups of meningococcus, a bacterium that can cause meningitis. Besides X, five other serogroups (A, B, C, Y and W-135) are responsible for virtually all cases of the disease in humans. So far, vaccines do not seem to protect against serogroup X N. meningitidis disease. 

Y is for young. Babies and young children are at the greatest risk of suffering severe complications if they contract a vaccine-preventable disease. They can start their shots at two months old and will need additional doses at four, six, 12 and 18 months of age for the best protection.

Z is for zero risk. No vaccine will ever give you perfect immunity from a particular disease; there is still a risk of contracting a disease that you have been vaccinated against, but it is drastically lower. Even if you do, you should be protected from the worst of the possible complications and side effects.