– Currently in US two covid vaccines are authorized for emergency use- Pfizer-BioNTech and Moderna.
– Inorder to meet the needs of vaccinating at least 80% of the US population needed to achieve “herd immunity”, more vaccination supply is necessary.
– Three other big companies are very promising and are in phase 3 clinical trials.
1) Johnson & Johnson/Janssen vaccine:
-Ad26.COV2.S, also known as Johnson & Johnson COVID-19 vaccine and Janssen COVID-19 vaccine.
– It is a single dose vaccine.
– Neutralizing antibodies against Covid-19 were detected in 90 percent of study participants at Day 29 and 100 percent of participants aged 18-55 years at Day 57.
– It uses a harmless cold virus called adenovirus 26 to carry the “spike” gene into the body which then provokes an immune response.
– J&J’s Covid-19 vaccine has several advantages. This vaccine is given in a single dose thus making distribution easier. Another advantage is that it can be stored at regular refrigerator temperatures. Therefore it would be popular in the developing countries because they would be easy to store and administer.
– The J&J technology has been used in the past in development of Ebola vaccine.
2) The AstraZeneca vaccine:
– It also uses a virus (adenovirus) that infects chimpanzees but doesn’t make people sick.
– The virus carries the genetic instructions for making spike protein from the coronavirus into cells to generate antibodies.
– As with the Pfizer and Moderna vaccines, this Covid-19 vaccine would require two shots.
-The trials so far show it could provide up to about 70% protection.
3) Novavax vaccine:
-The Novavax candidate is a protein-based vaccine created out of the genetic sequence for the novel coronavirus.
-The company uses virus-like nanoparticles as a base and scientists cover the base with the genetically engineered pieces of the coronavirus spike protein.
-This vaccine is given in two doses, 21 days apart.
-This kind of vaccine has been successfully used with other diseases like the vaccine for HPV and Sanofi’s flu vaccine.
Disclaimer: The information is intended to provide general education for patients and their families. The information provided does not constitute medical or health care advice for any individual and is not a substitute for medical and other professional advice and service.
Author Mahesh S. Ochaney, MD
