Vaccines: What You Need To Know


Vaccines have been around long enough now to validate their undeniable benefits to the world’s population. Vaccination remains one of the most effective ways to prevent and protect against more than 25 debilitating diseases. These include measles, polio, mumps, hepatitis A and B, rubella, diphtheria, meningitis, influenza and cervical cancer among others.

Understanding vaccines comes down to educating everyone about what goes into developing a vaccine, how it works and why it’s so important. In this article, we touch on some of the most important aspects to help pharmacists and their teams provide better information to customers and patients.

Why Are Vaccines Important?

Infectious diseases were the leading cause of death and disability across the world until the twentieth century. Vaccines have played a pivotal role in significantly reducing infections from the most dangerous diseases with some being wiped out completely. However, infectious diseases still are a major cause of concern in much of the developing world.

Diseases like smallpox and tetanus that killed or disabled millions of people have now been completed eradicated (small pox) or  are extremely rare (tetanus). To give an idea of how severe smallpox was, it claimed the lives of 300 million people during he 20th century alone.

Polio, a virus that spreads between people infecting the spinal cord, causing paralysis, is well on the way to being eradicated as well. Other diseases like measles and diphtheria have been reduced by up to 99.9% since introducing the relevant vaccines.

Are vaccines safe

Are Vaccines Safe?

Vaccines help the body’s immune system recognise and fight pathogens, such as viruses or bacteria. Contrary to what some may believe, vaccinations are based on real scientific research studies, development and trials. It’s not a game, nor does it belong to the long list of conspiracy theories. Have a look at this overview of do’s and don’ts.

What vaccines do

  • Protects children and adults from many serious and deadly diseases
  • Protects other people in your community – by helping to stop diseases from spreading to people who cannot have vaccines for medical reasons
  • A vaccine goes through rigorous safety tests for several years before being introduced while being monitored for any side effects
  • They may sometimes cause mild side effects that don’t last long
  • Some children may feel a little under the weather and have a sore arm for 2 or 3 days
  • A vaccine can reduce and even eradicate some diseases but only if enough people are vaccinated

What vaccines don’t do

  • Numerous scientific studies have found no evidence of a link between the MMR vaccine and autism
  • They don’t overload or weaken the immune system and giving children several vaccines at once is safe
  • No evidence suggesting it causes allergies or any other conditions
  • They do not contain mercury (thiomersal)
  • All the current evidence suggest it’s safer to be vaccinated than not vaccinating

Vaccines also don’t contain any ingredients that may cause harm in such small amounts. However, consult your doctor if you have any known allergies to eggs or gelatine.

Recommended: ‘Medicines and Healthcare Products Regulatory Agency (MHRA)

What Ingredients Go Into Vaccines?

Besides antigens (vaccines made from viruses or bacteria), vaccine ingredients include adjuvants, antibiotics, preservatives and stabilisers. Adjuvants are added to enhance the immune system response while antibiotics prevent contamination during the manufacturing process.

To put any wary minds at ease, each vaccine only contains a few micrograms of active ingredients, which is millionths of a gram. So what does all of this mean?

Putting Vaccine Ingredients Into Perspective

Considering that one paracetamol tablet contains 500 milligrams of the drug, the quantity of an active ingredient in most vaccines is several thousand times more. In fact, they can make hundreds of thousands of vaccines made from a single teaspoon of an active ingredient.

Some vaccines contain bacteria or viruses but they will either be severely weakened (attenuated) or killed altogether (inactivated). Many vaccines have parts of viruses or bacteria, which is usually proteins or sugars from the surface. While these stimulate the immune system, they cannot cause disease.

The amount of active ingredient in a vaccine is minuscule compared to the number of viruses and bacteria our bodies have to contend with daily. There are an estimated 100 trillion living bacteria on the skin of an average person, each of them containing thousands of proteins which constantly challenge our immune systems.

The Risk Anti-Vaxxers Pose

Over the years the number of anti-vaccination groups has grown with most of them spreading online through social media. More often than not, these anti-vaxxers make claims which may not be based on scientific evidence.

While they have the right to voice their opinions, without using real data, these movements put people’s lives at risk by making them more susceptible to serious illnesses. The major concern over anti-vaxxers is that these highly infectious and dangerous diseases could easily return and spread if people stop having vaccines. This brings us to the next section as we look at herd immunity.

vaccines herd immunity


Understanding Herd Immunity

Herd immunity can be described as a form of indirect protection from infectious diseases when a large percentage of a population group has become immune to a specific infection. This can be either through vaccination or previous infections. In theory, herd immunity provides some sort of protection for individuals who are not immune.

If enough people get vaccinated, the disease won’t spread too easily to those who cannot have vaccines, like people who are ill or have a weakened immune system. However, herd immunity does not protect against all diseases preventable through vaccines.

Tetanus, for example, doesn’t spread between people but is contracted from bacteria in the environment. It doesn’t matter how many people in the community are vaccinated against tetanus, herd immunity will not protect you. 

Is Herd Immunity A Viable Alternative?

If you live in an area with low vaccine coverage and you choose not to vaccinate your child, it is highly likely that many people they come into contact with have also not been vaccinated. It only takes one person to contract an infectious disease, like measles, to spread it among the unvaccinated people within the community. This was the case in Wales during the 2013 measles outbreak.

Herd immunity works on the following principle – that when a large number of the population
is vaccinated it is harder for the infection to spread to people who can’t have the vaccine such as

  • People with HIV
  • People without a fully-working immune system, especially a functioning spleen
  • Cancer patients on chemotherapy treatment with a weakened immune system
  • New-born babies who are too young for vaccinations
  • Individuals who are very ill in hospital

This is because in diseases that spread from person to person, it is more difficult to maintain a chain of infection the more people are vaccinated and as more people are vaccinated the protective effect from herd immunity increases. In most diseases for herd immunity to be effective between 80-95% of people would have to be vaccinated.

Covid-19 And The R-Number In The UK

R-number is short for reproduction number (R) which is the average number of  secondary infections caused by 1 infected person. If R is 1, every infected person will infect 1 other person which makes the total number of new infections stable. If R is 2, every infected person will infect 2 other people and so on.

The R-number for Covid-19 has fluctuated since the initial outbreak, starting at around 3 to 4. Mainly thanks to social distancing, travel restrictions and the lockdown, that number is now between 0.7 and 1.0. in the UK.

Diseases that have very high R-values – for instance measles, which can have a R number between 12 and 18 in populations without immunity  can result in explosive infections.To put Covid-19 into context the seasonal flu R number is roughly 1.3. However R in the case of both measles and seasonal flu is actually much lower as there are vaccines available.

R should always be calculated with the number of currently infected people. If R equals 1 with 100,000 people infected, it is different than when R equals 1 with 1,000 current infections.

Related: ‘How R Is Estimated

Final Thoughts

According to the World Health Organisation, most children receive their vaccinations on time but nearly 20 million worldwide don’t. This will put them at risk of contracting serious diseases, disability, ill-health and even death.

As new diseases or strains of existing pathogens appear, new vaccines will be developed. They will provide us with protection against more diseases, much like Covid-19 which presents a whole different challenge altogether.

As always, VirtualOutcomes is here to support you and your team with online training modules and have recently produced a course on vaccines which explains not only how they work but also looks at the various different types available. VirtualOutcomes also has a  large library of courses including courses on diabetes, sepsis, strokes, asthma attacks and our coveted Health Champion Training. Visit our website for more information and follow our blog for all the latest updates.