The US-based pharma company Moderna Inc, which recently claimed its vaccine efficacy (based on interim data) was 95 per cent, produces potent anti-bodies in human bodies that can last only three months, a new study has shown. The study, conducted by the National Institute for Allergies and Infectious Diseases (NIAID) and published in the New England Journal of Medicine, says the conclusion was derived after immune system analysis of 34 adult participants from the stage 1 clinical trial.
It says the anti-bodies that the vaccine produces after intake to stop coronavirus last only three months. It adds the anti-bodies declined slightly over time but remained elevated in all the participants even 3 months after the vaccination. It says the issue, however, is not a cause of concern.
NIAID director Anthony Fauci and other infectious diseases experts say it is possible that our bodies would remember the virus and could produce more anti-bodies if exposed to the virus again. As per the study, Moderna's vaccine also generated a certain type of immune cell, which could help in the memory response against Covid-19. However, more studies are needed to authenticate the claim, it said.
Meanwhile, Moderna has applied for an emergency use authorisation to the US Food and Drug Administration (FDA) and the application will be reviewed on December 17. Moderna's vaccine -- called mRNA-1273 -- is based on the latest and cutting edge mRNA technique and is administered in two doses after 28 days.
Moderna's COVID-19 trials, also known as the COVE study, enrolled more than 30,000 participants in the US and was conducted in collaboration with the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), and the Biomedical Advanced Research and Development Authority (BARDA).
In a separate statement, Moderna had earlier said its COVID-19 vaccine candidate remains stable for 30 days at 2-degree Celsius to 8-degree Celsius, the temperature of a standard home or medical refrigerator. It also said mRNA-1273 remains stable at -200 C (-40F) for up to six months, at refrigerated conditions for up to 30 days and room temperature for up to 12 hours.
What is mRNA technique?
The "messenger RNA" technique will be used for the first time if these vaccines -- of Moderna and Pfizer -- get the permission for the mass rollout. Though the technique was developed in the 1990s, scientists Weissman and colleague Katalin Kariko were the first one to use the mRNA technique to address a dangerous inflammatory response seen in animals. Notably, Kariko is now a senior vice president at BioNTech and Weissan served as an adviser in the company. German pharma company BioNTech developed the vaccine along with Pfizer.
Using the mRNA technique, the vaccine directs our cells to grow Covid-19 antigens or spike proteins. Seeing these spike proteins, our immune system develops antibodies without being exposed to the virus.
This new technique is believed to be safer but more expensive than the traditional ones and there are little chances of spike proteins infecting a person from COVID-19. It's also faster to develop than traditional ones and helps in the making of immune cells, which further help in building antibodies against the virus.