Spain on March 16 joined the list of countries that have suspended the use of the Oxford-AstraZeneca COVID-19 vaccine, marketed in India under the brand Covishied, after reports of isolated cases of bleeding, blood clots and low platelet count in some of the nations.
France, Germany and Italy on March 15 said that they would hit pause on AstraZeneca shots, citing reported serious side-effects.
Over the last week, Denmark, Norway, Iceland, Bulgaria, Ireland, Netherlands, Indonesia and Portugal and Slovenia have also halted the use of the vaccine.
Meanwhile, Austria, Estonia, Lithuania, Latvia and Luxembourg have suspended a particular batch of the AstraZeneca vaccine, which has been delivered to 17 countries and included one million vaccines.
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.
The Democratic Republic of Congo, due to start administering the vaccine, postponed its campaign citing "precautionary measures". Similarly, Venezuela's vice-president also said the country would not approve the AstraZeneca vaccine for use, citing "complications" those inoculated had experienced.
Why countries are halting the AstraZeneca vaccine
Denmark was the first country to halt the AstraZeneca COVID-19 vaccine after reports of blood clots in some people, including one person who developed multiple clots and died 10 days after receiving at least one dose.
The health authorities, however, said "it cannot be concluded whether there is a link between the vaccine and the blood clots.”
Announcing its decision to suspend the vaccine, Norwegian authorities said four people under age 50 who had gotten the AstraZeneca vaccine had an unusually low number of blood platelets.
Blood clots can travel through the body and cause heart attacks, strokes and deadly blockages in the lungs.
In response to the suspensions, AstraZeneca said it had carefully reviewed the data on 17 million people who received doses across Europe and found there were 37 cases of people who developed blood clots.
It said there was “no evidence of an increased risk” of blood clots in any age group or gender in any country.
“This is much lower than would be expected to occur naturally in a general population of this size and is similar across other licensed COVID-19 vaccines,” the company said.
What does WHO say?
The World Health Organization and the European Medicines Agency have insisted the shot is safe and there is no link between the vaccine and reported blood clots.
"We do not want people to panic and we would, for the time being, recommend that countries continue vaccinating with AstraZeneca," WHO chief scientist Soumya Swaminathan said on March 15.
"So far, we do not find an association between these events and the vaccine," she added.
WHO safety experts are expected to meet on March 16 to discuss data from AstraZeneca vaccinations.
What is India planning to do about it?
The government has begun a deeper review of post-vaccination side effects and deaths although no cases of blood clots have been reported so far. "All deaths and hospitalisations following immunisation are going to be re-looked at," said Dr NK Arora, member of the National Task Force on COVID-19.
He said the AstraZeneca vaccine will not be singled out here. "We are reviewing all the deaths and hospitalisations irrespective of the vaccine received. Very soon we will know more about the situation," he added.
The AstraZeneca-Oxford COVID-19 vaccine, which is being produced by the Serum Institute of India, is part of the COVID-19 vaccination drive in India. Covishield and Bharat Biotech's Covaxin are being administered in India as part of the vaccination drive.Click here for Moneycontrol's full coverage of the COVID-19 outbreak