Is Coronavirus Vaccine ready?
As COVID-19 (coronavirus) has spread all over the globe causing a pandemic, we are taking several precautions against it. While everyone is waiting for situations to get better and this arises a question in our mind,
Is Coronavirus vaccine ready?
before that we must know
- how our Immune System fights infection,
- how Vaccines are developed,
- how Vaccines function.
Immune System - Body’s Defense
- When bacteria or viruses, invade the body, they attack and multiply. This invasion, called an infection, is what causes illness.
- Blood contains red blood cells, for carrying oxygen to tissues and organs, and white or immune cells, for fighting infection.
- White cells consists of:
- Macrophages
- swallow up and digest germs, plus dead or dying cells.
- Leave behind parts of the invading germs called antigens.
- B-lymphocytes
- Defensive white blood cells
- Produces antibodies that attack the antigens left behind by the macrophages.
- T-lymphocytes (Memory Cells) :
- Stores information about previously encountered virus or bacteria.
- How Immune System Fights Infection :
- Immune system sounds the alarm so your body knows there’s an infection.
- It begins releasing antibodies to fight the germ, which can take few days.
- The antibodies work to attack, weaken, and destroy the virus or bacteria.
- Later, immune system remembers the virus or bacteria. If the virus or bacteria invades again, your body can recognize it and quickly send out the right antibodies to attack.
- This protection against a certain disease is called immunity. In many cases, immunity lasts your whole life.
How Vaccines Work
- Vaccines help develop immunity by imitating or behaving like an infection.
- Vaccine enters your body and acts like a virus or bacteria.
- In response, Immune System attacks it and memorizes it.
- When real virus enters body, Immune system quickly attacks it, preventing from infection.
- In other words, Vaccine acts like an emergency drill for your immune system to train it for fighting the virus.
Types of Vaccines
- Live, attenuated vaccines
- Uses a weakened (or attenuated) form of the germ that causes a disease.
- Strong and long-lasting immune response.
- Not recommended for people with weaker immunity.
- 1 or 2 doses of most live vaccines can give you a lifetime of protection.
- Used against - Measles, Smallpox, Chickenpox, etc.
- Inactivated vaccines
- Uses the killed version of the germ that causes a disease.
- Doesn’t provide immunity that’s as strong as live vaccines.
- Needs several doses over time (booster shots) in order to get ongoing immunity.
- Used against - Polio, Flu, Hepatitis A, etc.
- Subunit, recombinant, polysaccharide, and conjugate vaccines
- Uses specific pieces of the germ, like its protein, sugar, or capsid.
- Used against - Hepatitis B, Hib, etc
- Toxoid vaccines
- Uses bacteria that produce toxins (poisons) in the body.
- Toxins are weakened so they cannot cause illness. Weakened toxins are called toxoids.
- Used against - Tetanus, Diptheria.
Current situation of Vaccine for COVID-19
- Scientists are still working to create new types of vaccines? Here are 2 exciting examples:
- DNA vaccines are easy and inexpensive to make and they produce strong, long-term immunity.
- mRNA vaccines act like a natural infection, so they're especially good at teaching the immune system how to fight germs.
- Many Scientists and medical research organisations are trying to develop mRNA vaccine against COVID 19.
- Moderna Therapeutics has developed a vaccine against COVID-19, and has started trials on humans, skipping the usual tests on animals.
How are Vaccines developed and how long it takes?
- Vaccine production has several stages.
- First, the antigen itself is generated.
- Viruses are grown either on primary cells such as chicken eggs or on continuous cell lines such as cultured human cells.
- Bacteria are grown in bioreactors. Likewise, a recombinant protein derived from the viruses or bacteria can be generated in yeast, bacteria, or cell cultures.
- After production, clinical trials are run which are generally in 3 phases,
- Safety - to check for negative effects.
- Efficacy - to check efficiency and reliability.
- Expansion - to test on a large group of people and studying the behavior of it on those people living normal routine.
- Once the clinical trials are passed, there are legal procedures to license the vaccine to produce it on larger scale for common people.
This whole process of development, trials, legalization and production can take couple of years.
As COVID 19 vaccine is been tested directly on humans currently in Seattle, it can take upto 2 years for the Coronavirus (COVID-19) vaccine to reach us.
As these people are working hard to develop the vaccine, we need to buy them time by maintaining precautions.
This virus is not deadly, but is contagious and infects large number of people. While, India and many developing countries have limited health facilities for COVID-19 and if infected people count crosses the health services capacity, then death toll may increase, as doctors need to chose whom to treat first.
So, you are the one who can save yourself and others and help in preventing India entering the stage 3 epidemic.
Also, if you want to know more about how coronavirus attacks our body and how it works, please read the previous blog
Note: All the above information is from authorized sources and organisations.
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Author - Jayesh Lilani
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