From birth, we are constantly exposed to many different viruses, bacteria and other microbes. Most are not harmful, many are beneficial but some can cause disease.
The body’s immune system helps protect us against infections. When we are exposed to infection, the immune system triggers a series of responses to neutralize the microbes and limit their harmful effects. Exposure to an infectious disease often gives lifelong protection (immunity) so we do not contract the same disease again. Our immune system “remembers” the microbe.
With the threat brought by the COVID-19 pandemic, vaccination continues to be critically important. The pandemic has caused a decline in the number of children receiving routine immunizations, which could lead to an increase in illness and death from preventable diseases.
With the continuous change around the world, and political conflicts we can never tell what will happen to countries all over the globe, in preparation for the unpredictable future we need to anticipate and here vaccine plays a vital role in humanity.
What is a Vaccine?
We’re protected from infectious disease by our immune system, which destroys disease-causing germs – also known as pathogens – when they invade the body. If our immune system isn’t quick or strong enough to prevent pathogens from taking hold, then we get ill.
We use vaccines to stop this from happening. A vaccine provides a controlled exposure to a pathogen, training and strengthening the immune system so it can fight that disease quickly and effectively in the future. By imitating an infection, the vaccine protects us against the real thing.
How do vaccines work?
Vaccines teach your immune system how to create antibodies that protect you from diseases. It’s much safer for your immune system to learn this through vaccination than by catching the diseases and treating them. Once your immune system knows how to fight a disease, it can often protect you for many years.
Are vaccines safe?
Vaccines are among the safest medical products available, and scientists are working to make sure they are made even safer. Every vaccine undergoes extensive testing before being licensed, and vaccine safety continues to be monitored as long as a vaccine is in use.
Most side effects from vaccination are minor, such as soreness where the injection was given or a low-grade fever. These side effects do not last long and are treatable.
Serious reactions are very rare. The tiny risk of a serious reaction from a vaccination must be weighed against the very real risk of getting a dangerous vaccine-preventable disease or suffering complications from it.
Why Vaccines are important?
They protect us from dangerous diseases. In some regions or populations, dangerous diseases are constantly present (endemic). Examples include hepatitis B, cholera and polio. So long as these diseases are around, we need vaccines to bolster our immune systems and protect us from harm.
They protect children and the elderly. Our immune systems are strongest in adulthood, meaning that young children and the elderly are particularly susceptible to dangerous infections. By strengthening our immune systems early and late on in life, vaccines bypass this risk.
They protect the vulnerable. If enough of a population is vaccinated, infections can’t spread from person to person, which means that everyone has a high level of protection – even those who don’t have immunity.This is known as herd protection (or herd immunity). It’s important because not everyone can be directly protected with vaccines – some people are unresponsive to them or have allergies or health conditions that prevent them from taking them.
They can help us control epidemics. In a world of denser cities, increased international travel, migration and ecological change, the ability of emerging infectious diseases (such as Ebola) to spread and cause devastation is increasing. Vaccines can be a key tool in managing this threat – but only if we have them ready for diseases when they appear.
They can help limit drug resistance. Medicine relies on being able to treat infectious diseases with antimicrobial drugs, such as antibiotics, but overuse and misuse of these drugs is leading to infections becoming resistant to them. By preventing infections that would require drug treatments, vaccines reduce the opportunity for drug resistance to develop.
They are our most effective health intervention. Vaccines prevent an estimated 2–3 million deaths worldwide every year. But, a further 1.5 million lives could be saved annually with better global vaccine coverage.