At least 10 European countries have so far suspended the use of the Oxford University-AstraZeneca COVID-19 vaccine. Denmark, Norway and Iceland halted the use of the vaccine, known as Covishield in India, citing reports of serious cases of blood clots among people vaccinated with the AstraZeneca vaccine.
Following the suit, Austria, Italy, Romania, Estonia, Latvia, Lithuania and Luxemburg suspended the use of vaccines from a particular batch, which was sent to 17 European countries and consisted of one million jabs.
Meanwhile, Thailand on March 12 delayed its roll-out of the AstraZeneca vaccine over blood clot fears. "Though the quality of AstraZeneca is good, some countries have asked for a delay. We will delay (as well)," said Piyasakol Sakolsatayadorn, an advisor for the country's COVID-19 vaccine committee, in a press conference.
Denmark, the first to announce it was suspending the jab, said that the move was precautionary. "It has not been determined, at the time being, that there is a link between the vaccine and the blood clots," the country's Health Authority said.
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 Danish suspension, which will be reviewed after two weeks, is expected to slow down the country's vaccination campaign. Around 25 percent of those who have received the first dose in Denmark, a country of 5.8 million, were given the AstraZeneca jab.
Meanwhile, the European Medicines Agency (EMA) said that information available so far indicated the risk of blood clots in those vaccinated against COVID-19 was "no higher than that seen in the general population."
It also said that European countries could keep using the AstraZeneca vaccine while the issue was investigated, concluding that "the vaccine's benefits continue to outweigh its risks".
As of March 9, 22 cases of blood clots had been reported among more than three million people vaccinated in the European Economic Area, the EMA said, as per an AFP report.
AstraZeneca, an Anglo-Swedish company that developed the vaccine with Oxford University, defended the safety of its product.
"The safety of the vaccine has been extensively studied in phase III clinical trials and peer-reviewed data confirms the vaccine has been generally well-tolerated," a spokesman for the group told AFP.
Meanwhile, India has continued to administer the AstraZeneca shot as scheduled. The government had granted emergency use authorisation to AstraZeneca's Covishield vaccine and Bharat Biotech's Covaxin.
(With inputs from agencies)Click here for Moneycontrol's full coverage of the COVID-19 outbreak