The US-based pharmaceutical giants Pfizer and German biotech firm BioNTech have decided to expand their Phase 3 COVID-19 vaccine candidate trials to 44,000 participants.
The companies said that their initial goal of 30,000 participants will be attained by next week and with the new expansion, they are focusing to increase diversity in participants.
If the trials finish successfully the company expects to give a decisive result on the efficacy of the vaccine by October.
The expansion would allow the companies to enroll diversified trial participants including people from 16 years, people with chronic diseases, stable HIV, Hepatitis C or Hepatitis B infection.
The proposal of expansion was made to the US Food and Drug Administration(FDA) and the authorities have to approve the changes made in phase 3 before it can go for trial.
Pfizer and BioNTech are among the first in the US to study the effectiveness of data in the Phase 3 trial itself.
The companies have announced positive results for the Phase 1 trials of their second COVID-19 vaccine BNTI62b2 or b2 participant in August and stated that the latest participant has lesser side effects compared to the first.
The vaccine uses messenger RNA (mRNA) to copy the surface of the coronavirus and to train the immune system to understand the virus and neutralize it.
The company expects to submit the vaccine for regulatory approval by October and supply nearly 100 million dozen by the end of this year and 1.3 billion by the end of 2021.
In the US, several companies have already started their Phase 3 clinical trials including the vaccine candidate AZD1222 by Oxford University and Vaccitech, vaccine candidate mRNA-1273 by the US National Institute of Allergy and Infectious Diseases (NIAID) and American biotechnology company Moderna.