The second wave of the COVID-19 pandemic put the world under immense pressure once again. While global vaccination campaigns accelerated, questions remained about vaccine effectiveness and safety. India, running one of the world’s largest coronavirus immunization programs, played a pivotal role in vaccine development and distribution.
India’s COVID-19 Vaccines—Covishield and Covaxin
Covaxin is an inactivated vaccine developed using samples isolated by India’s National Institute of Virology. It works by introducing a destroyed form of the COVID virus into the body. When the immune system later encounters the live virus, it can quickly produce antibodies to combat it.
Covishield is based on a weakened strain of the common cold virus (adenovirus from chimpanzees), modified to resemble the coronavirus. International clinical trials showed the Oxford-AstraZeneca vaccine to be 90% effective when people received a half dose followed by a full dose.
Ingredients Used in COVID-19 Vaccines
The Pfizer-BioNTech and Moderna vaccines are mRNA (messenger ribonucleic acid) vaccines approved for emergency use. Unlike traditional vaccines that use inactivated pathogens, mRNA vaccines deliver genetic instructions to cells to temporarily produce a viral protein that activates an immune response.
Pfizer-BioNTech Vaccine Ingredients:
mRNA: The only active component — provides genetic instructions to produce a viral protein that triggers an immune response, causing the body to produce protective antibodies against COVID-19.
Lipids: Protect the mRNA and allow it to enter cells effectively. Includes 1,2-distearoyl-sn-glycero-3-phosphocholine, cholesterol, and polyethylene glycol compounds.
Salts: Help regulate the body’s acidity. Includes dibasic sodium phosphate dihydrate, sodium chloride, monobasic potassium phosphate, and potassium chloride.
Sugar (Sucrose): Helps the vaccine molecules maintain their shape while frozen.
Moderna COVID-19 Vaccine Ingredients: Includes acids, acid stabilizers (tromethamine and tromethamine hydrochloride), acetic acid, sucrose, sodium acetate, and sugar—all working together to keep the vaccine stable after manufacturing.
How Effective Are the Vaccines?
Vaccines work by triggering an immune response linked to protection. The vaccine produces neutralizing antibodies in reaction to the virus, preventing it from infecting cells. Most vaccines — including those for measles, hepatitis B, and seasonal flu — produce strong antibody responses that are linked to long-term immunity.
The SARS-CoV-2 protein introduced by the vaccine does not make the recipient sick. The viral protein does its job of training the immune system and then disappears over time. Immune cells continue to recognize the virus even after vaccination, enabling rapid antibody production if exposed.
India’s Vaccination Drive — Status and Challenges
India administered approximately 160 million doses of the coronavirus vaccine, predominantly using Covishield (locally produced AstraZeneca) and Covaxin (developed by Bharat Biotech). From May 2021, the vaccine was made available to people below 45 years of age.
The second wave brought significant challenges, including vaccine shortages that impacted the rollout. Around 30 million people were still pending their second dose. India also received a green signal from DCGI (Drug Controller General of India) for importing the Russian-made Sputnik V vaccine, with Dr. Reddy’s Laboratories partnering with the Russian Direct Investment Fund (RDIF) for import and distribution.
The Sputnik V vaccine requires a dosage of 0.5 ml, injected 21 days apart, and stored at -18°C. India committed to producing up to 50 million doses domestically by mid-2021.
Conclusion
There is no doubt about the quality and effectiveness of vaccines developed and administered in India. Both Covishield and Covaxin underwent strict safety and efficacy checks before approval. Getting vaccinated remains the most effective way to protect yourself and your community against COVID-19. Along with vaccination, maintaining good health practices — proper nutrition, supplementation, and an active lifestyle — remains essential for long-term immunity and well-being.
— Dr. Sanjay Agrawal
Leading Pharmaceutical Consultant and Editor-in-Chief of IJMToday
