Developing a vaccine during a pandemic

It has been almost a year since the first case of COVID-19 was reported in China. Researchers across the world are trying to find a permanent cure against this deadly virus. Many countries have initiated clinical trials – governments, companies wig shop online nike air max for sale nike air max for sale nike air max 98 nike air max 90 sale custom jerseys nike air jordan men’s sneakers jordan shoes online adidas store custom jerseys original nfl teams jordan 3s dallas cowboys adidas yeezy for men adidas yeezy shoes and educational laboratories are working towards a common goal of COVID-19-free world. In order to attain this goal, there are a few possibilities, such as discovering new drug molecules, repurposing of old molecules for treatment, developing herd immunity, and developing a vaccine. The most strategic method to neutralize the virus is developing a vaccine.

What is a vaccine?

A vaccine is a biological product that is administered in the body to provide acquired immunity to a pathogen. It contains a weakened or dead pathogen or its toxin. It stimulates the body’s immune system which can recognize disease-causing pathogens and fight by producing antibodies. The helper T-cells store the memory of attack to prevent future attacks by the same pathogen. Other types of vaccines such as subunit, recombinant, polysaccharide, and conjugate vaccines use specific pieces of the germ — its protein, sugar, or capsid (a casing around the germ) to help the body fight the pathogens.

How is a new vaccine developed?

Vaccine development is a complex and lengthy procedure. It takes upto a maximum of 15 years for a vaccine to enter the market for human use. Vaccine development takes place primarily in two stages: pre-clinical and clinical development.

Stages of vaccine development:

  1. Exploratory stage (2-3 years): This stage includes basic research or using existing literature related to an infection.
  2. Pre-clinical stage (1-2 years):  Research trials are conducted on a laboratory-scale on tissue or cell cultures and then are tested on animals which includes four steps as follows:
  3. Discovery or identifying new compounds through a screening process that becomes a potential drug candidate.
  4. Conceptualization of vaccine.

iii.        Efficacy is testing in test tubes and small animals (such as mice, guinea pigs or rabbits).

  1. The vaccine is manufactured according to Good Manufacturing Practice (GMP) standards.
  2. Clinical stage (3 to 7 years): Research trials are conducted on human volunteers in different phases.

Phase 1: It is conducted on a small group of usually 20-80 healthy volunteers who receive a trail vaccine to assess its safety.

Phase 2: This phase is conducted to determine efficacy on a larger group of 100 to thousand healthy volunteers. The potential candidate results are compared with placebo (without drug). It also helps to determine a safe dosage in a suitable form and whether it has any side effects.

Phase 3: Unlike other phases, this trial is conducted on thousands of diseased volunteers. It confirms efficacy and safety in comparison to the existing standard of care over a definite period.

Phase 4: This phase conducted to test for efficacy and safety after the vaccine is approved and licensed. It is also known as post-marketing surveillance which monitors if the vaccine has any long-term efficacy.

  1. Regulatory review and approval (1 year): A New Drug Application (NDA) is filled which is reviewed and approved by a regulatory authority.

After approval, the vaccine can be licensed to market the product for human use. Then the vaccine is manufactured on large-scale, tested for quality control and administered to patients on a doctor’s prescription.


Figure 1 Stages of vaccine development

How is vaccine development taking place during this pandemic?

It usually takes around 10-15 years to develop a safe and efficient vaccine. During this pandemic, the vaccine development process is taking place at a much faster rate. The global aim is to develop a vaccine in one year which as of now is a reasonable aim to attain.

Countries like the United States of America, the United Kingdom, China, India, Germany, Italy, and Israel are in the process of developing a vaccine for COVID-19.

Russia: The country has the only approved vaccine against COVID-19 named Sputnik V, formerly known as Gam-COVID-Vac and developed by the Gamaleya Research Institute in Moscow. The vaccine was approved by the Ministry of Health of the Russian Federation on 11 August even though it has not yet entered Phase 3 clinical trials.

The United States of America: The National Institute of Allergy and Infectious Diseases (NIAID) with Biotech company Moderna are working on a vaccine named mRNA-1273 and is in Phase 3. Johnson & Johnson (USA) is working with Biomedical advanced research and development Authority (BARDA) on a vaccine candidate termed Ad26.COV2-S that is in the pre-clinical stage.

The United Kingdom: The University of Oxford with Jenner Institute is currently working on a vaccine named AZD1222 which is in Phase 3. The Serum Institute of India has collaborated for the trial with the University of Oxford and global pharma giant AstraZeneca.

China: Tianjin-based CanSino Biologics Inc is sponsoring trails for two candidates Ad5-nCoV and an unannounced one. Ad5-nCoV is in Phase 3 while the other one is in early research.

India: Pune-based the National Institute of Virology (NIV) has collaborated with Bharat Biotech International Limited (MMIL) for Covaxin that is in Phase 2 trials. Another vaccine by Zydas Cadila will go in for the Phase 1 and 2 of human clinical trials.

Germany: A German, vaccine named BNT162 developed by German company Biotech and the US-based Pfizer is in the clinical trial stage 2/3.

Israel:  Israel Institute for Biological Research MigVax is set to begin human trials.




Leave a Reply

Your email address will not be published.