How do Vaccines Work?

2020 has been an unforgettable year, largely due to COVID-19 which has transformed the world as we know it. The global response has been a massive one, with efforts led by the World Health Organization and its partners. From tracking the pandemic, advising on critical interventions, distributing vital medical supplies to those in need, they are doing their best to guide the world out of this crisis.

Alongside these efforts, there is a race on to develop and deploy safe and effective vaccines to fight the virus. Statista.com noted that as of December 16, 2020, there were nearly 990 drugs and vaccines in development targeting the coronavirus disease (COVID-19). Front runners include Pfizer-BioNTech, Moderna (MRNA) and AstraZenaca. The rapid development of COVID-19 vaccines is also unprecedented, given the severity and scale of the crisis. Though the approval process typically takes 10 to 15 years, the U.S. Food and Drug Administration has granted emergency authorization to vaccines made by Pfizer and Moderna in less than a year. Before now, the fastest-ever vaccine—for mumps—took four years to develop in the 1960s.

However, just what are vaccines and how do they help us?

Vaccines save millions of lives each year. A biological preparation, it works by training and preparing the body’s natural defences, known as the immune system to recognize and fight off the viruses and bacteria they target.

A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins. 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. Vaccines can be prophylactic (to prevent or ameliorate the effects of a future infection by a natural or “wild” pathogen), or therapeutic (to fight a disease that has already occurred, such as cancer).

The administration of vaccines is called vaccination and is generally done by a trained healthcare professional. Vaccinations are the most effective method of preventing infectious diseases, with widespread immunity due to vaccination is largely responsible for the worldwide eradication of smallpox and the restriction of diseases such as polio, measles, and tetanus from much of the world.

The effectiveness of vaccination has been widely studied and verified. For example, vaccines that have proven effective include the influenza vaccine, the Human Papilloma Virus (HPV) vaccine and the chicken pox vaccine. The World Health Organization (WHO) reports that licensed vaccines are currently available for twenty-five different preventable infections.

However, some people do suffer mild symptoms after being vaccinated, such as muscle aches or a raised temperature. This is not the disease itself, but the body’s response to the vaccine.

There have also been reports that some people have experienced severe allergic reactions—also known as Anaphylaxis—after getting a COVID-19 vaccine. Anaphylaxis is a serious allergic reaction that is rapid in onset and may cause death. It typically causes more than one of the following: an itchy rash, throat or tongue swelling, shortness of breath, vomiting, light-headedness, low blood pressure. These symptoms typically come on over minutes to hours. As an example, an allergic reaction is considered severe when a person needs to be treated with epinephrine or EpiPen© or if they must go to the hospital.

Allergic reactions are generally rare but if adequate precautions are taken before and after the vaccine, the pros of getting a vaccine outweigh the risks and you will be keeping yourself and your family safe.