The news that many countries, including Turkey, are starting to roll out programs for vaccination against COVID-19 (SARS-CoV-2) raises many questions in people’s minds, generally about the different types of vaccines, how they were developed so quickly, and how they work.

As a result, we have pulled together information from reputable scientific sources to give you a basic understanding of how vaccines work and the different types of vaccine available.

How were COVID-19 vaccines developed so quickly?

Creating a vaccine in under 1 year is no small feat. While the coronavirus pandemic made a new normal of mask-wearing and physical distancing, it also spurred global cooperation for vaccine research and distribution.

Under normal circumstances, making a vaccine can take up to 10–15 years. This is because of the complexity of vaccine development.

Amid a global pandemic, time was a luxury the world could not afford. Researchers quickly mobilized to share their coronavirus data with other scientists.

The ability to fast-track research and clinical trials was a direct result of this worldwide cooperation.

How vaccines work

A vaccine works by training the immune system to recognize and combat pathogens, either viruses or bacteria. To do this, certain molecules from the pathogen must be introduced into the body to trigger an immune response.

These molecules are called antigens, and they are present on all viruses and bacteria. By injecting these antigens into the body, the immune system can safely learn to recognize them as hostile invaders, produce antibodies, and remember them for the future. If the bacteria or virus reappears, the immune system will recognize the antigens immediately and attack aggressively well before the pathogen can spread and cause sickness.

How COVID-19 Vaccines Work

COVID-19 vaccines help our bodies develop immunity to the virus that causes COVID-19 without us having to get the illness. Different types of vaccines work in different ways to offer protection, but with all types of vaccines, the body is left with a supply of “memory” T-lymphocytes as well as B-lymphocytes that will remember how to fight that virus in the future.

It typically takes a few weeks for the body to produce T-lymphocytes and B-lymphocytes after vaccination. Therefore, it is possible that a person could be infected with the virus that causes COVID-19 just before or just after vaccination and then get sick because the vaccine did not have enough time to provide protection.

Sometimes after vaccination, the process of building immunity can cause symptoms, such as fever. These symptoms are normal and are a sign that the body is building immunity.

Types of Vaccines

Scientists around the world are developing many potential vaccines for COVID-19. These vaccines are all designed to teach the body’s immune system to safely recognize and block the virus that causes COVID-19.

Several different types of vaccines for COVID-19 have been developed, or are in development, including:

  • Inactivated or weakened virus vaccines, which use a form of the virus that has been inactivated or weakened so it doesn’t cause disease, but still generates an immune response.
  • Protein-based vaccines, which use harmless fragments of proteins or protein shells that mimic the COVID-19 virus to safely generate an immune response.
  • Viral vector vaccines, which use a virus that has been genetically engineered so that it can’t cause disease, but produces coronavirus proteins to safely generate an immune response.
  • RNA and DNA vaccines, a cutting-edge approach that uses genetically engineered RNA or DNA to generate a protein that itself safely prompts an immune response.

Sinovac vaccine

The Beijing-based biopharmaceutical company Sinovac is behind the CoronaVac, an inactivated vaccine.

It works by using killed viral particles to expose the body’s immune system to the virus without risking a serious disease response.

“CoronaVac is a more traditional method [of vaccine] that is successfully used in many well known vaccines like rabies,” Associate Prof Luo Dahai of the Nanyang Technological University told the BBC.

Interim results from phase 3 trials have shown that the vaccine is over 91% effective, according to Health Minister Fahrettin Koca, and the first batch of 3 million doses arrived in Turkey on December 30.

https://www.bbc.com/news/world-asia-china-55212787

Herd Immunity

Herd immunity is a form of indirect protection from infectious disease that occurs when a sufficient percentage of a population has become immune to an infection, whether through vaccination or previous infections, thereby reducing the likelihood of infection for individuals who lack immunity.

When someone is vaccinated, they are very likely to be protected against the targeted disease. But not everyone can be vaccinated. People with underlying health conditions that weaken their immune systems (such as cancer or HIV) or who have severe allergies to some vaccine components may not be able to get vaccinated with certain vaccines. These people can still be protected if they live in and amongst others who are vaccinated. When a lot of people in a community are vaccinated the pathogen has a hard time circulating because most of the people it encounters are immune. So the more that others are vaccinated, the less likely people who are unable to be protected by vaccines are at risk of even being exposed to the harmful pathogens.

Herd immunity is especially important for those people who not only can’t be vaccinated but may be more susceptible to the diseases we vaccinate against. No single vaccine provides 100% protection, and herd immunity does not provide full protection to those who cannot safely be vaccinated. But with herd immunity, these people will have substantial protection, thanks to those around them being vaccinated.

Vaccinating not only protects yourself, but also protects those in the community who are unable to be vaccinated. If you are able to, get vaccinated.

The Bottom Line

Getting vaccinated is one of many steps you can take to protect yourself and others from COVID-19.  Protection from COVID-19 is critically important because for some people, it can cause severe illness or death.

Stopping a pandemic requires using all the tools available. Vaccines work with your immune system so your body will be ready to fight the virus if you are exposed. Other steps, like masks and social distancing, help reduce your chance of being exposed to the virus or spreading it to others.

Together, COVID-19 vaccination and following government and Ministry of Health recommendations to protect yourself and others will offer the best protection from COVID-19.

Sources: https://www.publichealth.org/public-awareness/understanding-vaccines/vaccines-work/

https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/how-they-work.html

https://www.who.int/news-room/q-a-detail/coronavirus-disease-(covid-19)-vaccines

https://www.who.int/publications/m/item/draft-landscape-of-covid-19-candidate-vaccines

https://en.wikipedia.org/wiki/Herd_immunity

https://www.medicalnewstoday.com/articles/how-did-we-develop-a-covid-19-vaccine-so-quickly#Worldwide-collaboration

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