Vaccines Against COVID-19
Vaccine helps to enhance immunity against specific antigens. Vaccines contain itself a weakened or inactivate viral organisms or only a part of antigen which activate an immune response against that particular antigen within the body.
Type of Vaccines:
There are following types of vaccines are developed to target infectious organisms-
1. Inactivated Vaccines
2. Live-attenuated Vaccines
3. Messenger RNA (mRNA) Vaccines
4. Subunit, recombinant, polysaccharide and conjugate Vaccines
5. Toxoid Vaccines
6. Viral Vector Vaccines
1. Inactivated Vaccines:
This type vaccine is develop by the killed infectious organisms that causes a disease. This vaccines usually do not provide strong immunity as compare to live-attenuated vaccines. This type vaccines effective after booster shots (several doses required).
Example- Hepatitis A, Flu, Polio, Rabies, COVID-19 Vaccines like- CoronaVac, Sinopharm, Covaxin.
2. Live-attenuated Vaccines:
This type vaccine is develop by the weakened (or attenuated) form of infectious organisms that cause a disease. This vaccines are as same as natural infectious organism so it helps to prevent germ attack, it create a effective and long-time immune response. Single or two doses are enough to provide life-time protection against a germ.
Example- Measles, Mumps, Rubella (MMR combined vaccine), Rotavirus, Smallpox, Chickenpox, Yellow Fever.
3. Messenger RNA (mRNA) Vaccines:
This type vaccine is developed by the mRNA of that specific infectious organism that causes a disease. mRNA translate and helps to produce proteins which enhance immune response against that particular disease. This type vaccines take short time to production and they have no any risk of causing disease after vaccination.
Example- COVID-19 vaccines like- Pfizer (BioNTech), and Moderna.
4. Subunit, recombinant, polysaccharide and conjugate Vaccines:
This type vaccine is developed by using specific part of the infectious organism like- its protein, sugar or capsid. Due to use of only specific part of the organism, this type vaccines give a very effective immune response that targeted to disease causing part of the organism. Booster shots provide strong immunity against the disease.
Example- Hib (Haemophilus influenzae type b) disease, Hepatitis B, HPV (Human papillomavirus), Whooping cough (part of the DTaP combined vaccine), Pneumococcal disease, Meningococcal disease, Shingles, COVID-19 vaccines like- Novavax (Protein based).
5. Toxoid Vaccines:
This type vaccine is developed by using a toxin made by the infectious organism that causes a disease. This type vaccine helps to provide immunity against only the parts of the organism that cause a disease instead of whole organism. Booster shots are required to produce strong immunity against disease.
Example- Diphtheria vaccine, Tetanus vaccine.
6. Viral Vector Vaccines:
This type vaccine is developed by using viral vector technology. In this vaccine production the modified virus are used as a vector to provide protection. There are several different viruses have been used as vectors like Influenza, Vesicular Stomatitis Virus (VSV), Measles virus and Adenovirus.
Adenovirus is also used as a vector for vaccine production against SARS-CoV-2.
Example- COVID-19 vaccines like- Covishield (Oxford-AstraZeneca), Sputnik V, Johnson & Johnson vaccines.
How Vaccine works?
When you vaccinated, your B-lymphocyte cells are activated and detect the antigens in the vaccine. The B-lymphocyte cells will react if the real virus or infectious organism was attack to your body. B-lymphocyte cells multiply and form plasma cells and memory B-cells that are able to respond to the antigens in the vaccine.
The cloned cells are helps to produce two types cells-
a. Plasma cells
b. Memory B cells
Plasma cells are produced antibodies, which are helps to inactivate or kill the infectious organism. This response which is generated by B-lymphocytes is known as primary response.
After vaccination body continues making antibodies and memory B cells. After some time the antibodies production will stopped, but memory B cells will remain dormant in your body.
Vaccines Against COVID-19:
1. Vaccine brand name- Pfizer- BioNTech
Vaccine type- mRNA based
Country of origin- United States, Germany
Trial location- Multinational
Who can get this vaccine- People 16 years and older.
How many shots you will need- 2 shots given 3 weeks (21 days) apart.
When you fully vaccinated- 2 weeks after your second shot.
Efficacy rate- 95%
2. Vaccine Brand name- Moderna
Vaccine type- mRNA based
Country of origin- United States
Trial location- United States
Who can get this vaccine- People 18 years and older.
How many shots you will need- 2 shots given 4 weeks (28 days) apart.
When are you fully vaccinated- 2 weeks after second shot.
Efficacy rate- 94.1%
3. Vaccine brand name- Johnson & Johnson’s Janssen
Vaccine type- Viral Vector based
Country of origin- United States, Netherlands
Trial location- Multinational
Who can get this vaccine- People 18 years and older.
How many shots you will need- 1 shot.
When are you fully vaccinated- 2 weeks after your shot.
Efficacy rate- 72%
4. Vaccine brand name- Covishield — Oxford-AstraZeneca
Vaccine type- Viral Vector based
Country of origin- United Kingdom, Sweden
Trial location- Multinational
Who can get this vaccine- People 18 years and older.
How many shots you will need- 2 shots given 4 to 12 weeks apart.
When are you fully vaccinated- 2 weeks after second shot.
Efficacy rate- 76%
5. Vaccine brand name- Sputnik V
Vaccine type- Viral Vector based
Country of origin- Russia
Trial location- Russia
Who can get this vaccine- People 18 years and older.
How many shots you will need- 2 shots given 3 weeks (21 days) apart.
When are you fully vaccinated — 2 weeks after second shot.
Efficacy rate- 91.4%
6. Vaccine brand name- CoronaVac- Sinovac
Vaccine type- Inactivated Virus based
Country of origin- China
Trial location- Brazil
Who can get this vaccine- People 18 years and older.
How many shots you will need- 2 shots given 2 to 3 weeks (14–21 days) apart.
When are you fully vaccinated — 2 weeks after second shot.
Efficacy rate- 78%
7. Vaccine brand name- Sinopharm
Vaccine type- Inactivated Virus based
Country of origin- China
Trial location- Multinational
Who can get this vaccine- People 18 years and older.
How many shots you will need- 2 shots given 3 to 4 weeks (21–28 days) apart.
When are you fully vaccinated — 2 weeks after second shot.
Efficacy rate- 79%
8. Vaccine brand name- Covaxin- Bharat Biotech
Vaccine type- Inactivated Virus based
Country of Origin- India
Trial location- India
Who can get this vaccine- People 18 years and older.
How many shots you will need- 2 shots given 4 weeks (28 days) apart.
When are you fully vaccinated — 2 weeks after second shot.
Efficacy rate- 81%
9. Vaccine brand name- Novavax
Vaccine type- Protein based
Country of origin- United States
Trial location- United Kingdom and South Africa
Who can get this vaccine- People 18 years and older.
How many shots you will need- 2 shots given 3 weeks (21 days) apart.
When are you fully vaccinated — 2 weeks after second shot.
Efficacy rate- 89.3%
Side effects:
After getting vaccine first dose you may suffer with-
Arm where you got dose:
a. Pain
b. Redness
c. Swelling
Rest of the body:
a. Tiredness
b. Headache
c. Muscle pain
d. Chills
e. Fever
f. Nausea
After getting the second dose you may suffer more intense side effects. These side effects are the positive sign that your body immune system starts to producing antibodies against virus.
You may use medicine like Ibuprofen, Acetaminophen, Aspirin or Antihistamines for avoiding pain and discomfort which you faced post-vaccination. You should also use excess water and liquid diets to reduce any type discomfort.
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