India's drug regulator has allowed the AstraZeneca COVID-19 vaccine to be used for up to nine months from its manufacture date, as opposed to the prescribed six months, according to a document reviewed by Reuters and a source.
The approval, given to a licensed version of the drug made by the Serum Institute of India (SII) and exported to dozens of countries, could help health authorities minimise vaccine wastage and better plan their inoculation programmes.
Some African countries have only until the middle of next month to use up more than a million doses of the vaccine - branded Covishield by SII - if the shelf life is not extended.
"You are permitted to apply the shelf-life of 9 month to unlabelled vials available on hand," India's drugs controller-general, V.G. Somani, wrote late last month in reply to a request from the SII.
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.
AstraZeneca said in a statement last week that its product could be stored, transported and handled at normal refrigerated conditions for at least six months. The World Health Organization website also gives the shelf-life of Covishield and the South Korean-made AstraZeneca shot as six months.
Reuters has reviewed Somani's approval, which has been communicated to some African countries, but could not determine if his recommendation applied to unused vials. Each vial typically contains 5 millilitre of vaccine, or 10 doses.
The source, with direct knowledge of the matter but not authorised to discuss it publicly, said the approval was given based on data submitted by the SII. The source did not specify what kind of data was shared by the company, the world's biggest vaccine maker.
Somani, the SII and AstraZeneca did not immediately respond to requests for comment.
India has so far administered 55 million Covishield doses at home and exported nearly 64 million. India is also using another vaccine developed domestically by Bharat Biotech.Follow our full coverage of the coronavirus pandemic here.