THE GOOD AND THE BAD ABOUT VIRAL VACCINE TECHNOLOGIES LEADING FOREIGN VACCINES
across the world, they would help in finding out a vaccine or vaccines that will have lasting immunity and are safer for use.” (See accompanying interview.)
However, controversy broke out over the Indian effort when an overzealous Indian Council for Medical Research (ICMR), the country’s premier medical research agency, sent out a note telling the two Indian firms and their collaborators to ensure that Phase 1 and 2 trials were completed by August 15, India’s Independence Day. Bodies of experts, such as the Indian Academy of Science, protested strongly against the imposition of such deadlines to rush through critical research. K.I. Varaprasad Reddy, chairman, Shantha Biotechnics, Hyderabad (now a subsidiary of the French Sanofi), warns: “You cannot gloss over protocols and forego sequential safety in developing a vaccine. We cannot make a mockery of science. It will take at least 18 months to two years even in an emergency-like situation. What is dangerous is the practice of drug
OUR R&D AND MANUFACTURING TEAMS WORKED TIRELESSLY TO DEPLOY OUR PROPRIETARY TECH TO COVAXIN. WE HOPE THE HUMAN TRIALS WILL VALIDATE OUR EFFORTS”
KRISHNA ELLA Chairman & MD, Bharat Biotech, Hyderabad
LIVE VACCINE ATTENUATED PROS:
lasting Strong immunity and CONS:
to virulence; Risk of needs reversion cold chains
KILLED OR INACTIVATED VACCINE
PROS: No risk of virulence
CONS: Less immunogenic than live vaccine
RECOMBINANT PROTEIN VACCINE
PROS: Can be targeted to the key protein of the virus
CONS: Highly immunogenic only with an adjuvant
DNA VACCINE
PROS: Inexpensive, faster to make; potential for lasting immunity; no need
for cold chain; can make more vaccine doses with DNA than with RNA
CONS: Potential for genomic integration; allergic to DNA; unclear whether production can be scaled up rapidly
mRNA VACCINE
PROS: Easy and inexpensive; faster to make; potential for lasting immunity; no need for cold chain; no risk of genomic integration; adjuvants may help enhance the immune response when such vaccines are administered to older populations and may reduce the amount of RNA needed in each vaccine; safer to use as they are not produced using infectious elements
CONS: Unproven technology; no mRNA vaccine approved yet; need better understanding of the vaccine’s adverse effects
UNIVERSITY OF OXFORD / ASTRA-ZENECA
TYPE: Non–replicating adenovirus vector-based vaccine
STAGE: Phase 2b/ 3
Manufacturing contracts in place for worldwide supply
BIONTECH/ FOSUN PHARMA/ PFIZER
TYPE: Lipid nanoparticle encapsulated mRNA vaccine
STAGE: Phase 1/ 2
Phase 3 trial expected to start in July
SINOVAC BIOTECH
TYPE: Inactivated viral vaccine + alum
STAGE: Phase 3 trial under way in China and Brazil
MODERNA / NIAID
TYPE: Lipid nanoparticle encapsulated mRNA vaccine
STAGE: Phase 2
Phase 3 trial expected to start in July
JOHNSON & JOHNSON
TYPE: Non– replicating adenovirus vector-based vaccine
STAGE: Preclinical
Phase 1/ 2 trials to begin in July