One way to stop the spread of a virus is through vaccines.
Vaccine works by helping our bodies combat the virus when it enters the human body. When germs, like the virus that causes COVID-19, invade our bodies, they attack and multiply. This invasion, called an infection, is what causes the disease.
In a careful sequence of steps, vaccine production continues to make sure that the final product is both safe and successful. The process of basic research and preclinical studies in animals comes first. After that, vaccines are implemented in small phase 1 studies focusing on protection, and then in larger phase 2 studies focusing on efficacy.
Several COVID-19 vaccines are in clinical trials at present. Before authorizing vaccines for COVID-19 use, the Food and Drug Administration (FDA) will review the outcomes of these trials. But because COVID-19 vaccines are desperately needed and the FDA’s vaccine approval process can take months to years, the FDA will first offer COVID-19 vaccines emergency use authorization based on less data than is usually necessary.
Last December 31, the World Health Organization (WHO) listed the COVID-19 mRNA vaccine for emergency use, making the Pfizer/BioNTech vaccine the first to receive emergency validation from WHO since the outbreak.
Below is a table listing the various vaccines that has been approved by US or UK Food and drug administration
| ChAdOx1 nCoV-19 (University of Oxford and AstraZeneca)2 | BNT162b2 (BioNTech and Pfizer) | Mrna-1273 (NIAID and Moderna) | |
| Type of Vaccine | Non-replicating viral vector | mRNA | mRNA |
| Current phase of Clincal Trial | Phase 3 | Phase 3 | Phase 3 |
| Vaccine Dosing and Efficacy | |||
| Dose and Frequency | 2 doses 6 to 12 weeks apart | 2 doses 21 days apart | 2 doses 28 days apart |
| Vaccine Efficacy | 62% (full dose x 2) 90% (half dose then full dose) 14 days after the 2nd dose | 95% 7 days after the 2nd dose | 94.10% 14 days after the 2nd dose |
| Adverse events | · Injection site pain & tenderness · Myalgia · Fatigue · Headache · Malaise · Chills | · Pain on injection site · Fatigue · Headache · Fever · Lymphadenopathy | · Pain on injection site · Axillary lymphadenopathy · Erythema & swelling on injection site · Fever · Headache · Fatigue · Myalgia · Arthralgia · Nausea · Vomiting · Chills |
| Serious Adverse events | · Shoulder injury related to vaccine administration · Right axillary lymphadenopathy · Paroxysmal arrythmia · Right leg paresthesia | · Intractable nausea and vomiting · Facial swelling · Rheumatoid arthritis · Dyspnea with exertion · Peripheral edema · Autonomic dysfunction · B-Cell lymphocytic lymphoma |
*Data presented are based on the interim analysis of vaccines with published phase 3 trials. May change depending on the results of further studies.
Vaccines are usually made from weakened or inactivated versions of the virus. However, newer technologies of vaccine manufacturing have been found, such as the ones employed in developing the COVID vaccine.
For AstraZeneca, it makes use of specific regions of the target pathogen, in this case COVID-19 virus, to create specific immune reactions. A weakened version of the common cold virus that contains the SARS-CoV-2 spike 2 protein is used. This approach has been successful before when it was used in making the Ebola vaccine.
On the other hand, Pfizer and Moderna, are based on the messenger-Ribonucleic acid (mRNA). MRNA teaches our cells to produce proteins, which does not cause disease. It triggers an immune response against the virus, enabling the person to develop immunity.
Aside from the listed vaccines in the table, there are other COVID vaccines being studied and produced.
There are 2 Chinese developed vaccines which are Sinopharm and Sinovac. Both have passed their Phase 3 clinical trials. Reported efficacy is 79% for Sinopharm and 78% for Sinovac. However, at present, details of the phase 3 trials are not published yet.
The Sputnik V vaccine by Gamaleya Institute, Russian based, is said to have a 91.4% efficacy reported. It is engineered using viral vector, similar to AstraZeneca.
Janssen vaccine by Johnson & Johnson also uses the viral adenovirus vector technology. Their interim data is not available until late-January as reported.
Here are some vaccines that may be administered in the country:
1. BioNTech
2. AstraZeneca
3. Sputnik V
4. Moderna
5. Janssen
6. Sinovac
7. Sinopharm
8. Clover
9. Novavax
One of the steps that you can do to protect yourself and others from COVID-19 is to get vaccinated. The vaccine will protect us from acquiring the disease or suffering from the severe symptoms of the disease. Hence, it is important that we should all be informed of the vaccines available before receiving one. This will be one big step for all of us in eradicating the disease and eventually putting a halt to this pandemic.