Dr NK Arora, Chairman of India's COVID-19 Working Group of NTAGI, on August 26 clarified that there is no proposal to change the gap between two doses of Covishield COVID-19 vaccine.
Arora's statement came hours after media reports claimed that the government is reconsidering the 84-day gap span of Covishield doses.
The current gap between two doses of the vaccine has been set at 12-16 weeks for all adults.
World Health Organization (WHO) recommends an interval of 8 to 12 weeks between two doses of the Covishield vaccine.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
"There are several studies and programmatic data collection processes are on to assess the vaccine effectiveness. NTAGI is reviewing the vaccine effectiveness data on a regular basis. Currently, there is no proposal for change in the dose interval for Covishield, Covaxin and Sputnik V is under consideration," Arora said, as quoted by PTI.
The government in May had further extended the gap between the two doses of Covishield from 6-8 weeks to 12-16 weeks and said the decision to increase the gap was based on scientific evidence.
Based on emerging data, India would revisit the dosage interval for the Covishield vaccine and take appropriate action, Arora had earlier said.