Washington (USA) | Jagran News Desk: The United States Food and Drug Administration (FDA) and Centers for Disease Control (CDC) on Tuesday recommended to pause the use of single-dose Johnson and Johnson's COVID-19 vaccine after six recipients developed "rare and severe" type of blood clot.

In a joint statement, the US agencies said that serious blood clot concerns have been reported in six cases -- all among women in the age group of 18 to 48 years -- after six to 13 days of inoculation. It said that CDC will further "review these cases and assess their potential significance".

"FDA will review that analysis as it also investigates these cases. Until that process is complete, we are recommending a pause in the use of this vaccine out of an abundance of caution," the statement read.

"This is important, in part, to ensure that the health care provider community is aware of the potential for these adverse events and can plan for proper recognition and management due to the unique treatment required with this type of blood clot," it added.

The J&J vaccine received emergency use authorization from the FDA in late February with great fanfare, with hopes that its single-dose and relatively simple storage requirements would speed vaccinations across the country.

Yet the shot only makes up a small fraction of the doses administered in the U.S. as J&J has been plagued by production delays and manufacturing errors at the Baltimore plant of a contractor.

Last week the drugmaker took over the facility to scale up production in hopes of meeting its commitment to the U.S. government of providing about 100 million doses by the end of May.

Until now concern about the unusual blood clots has centered on the vaccine from AstraZeneca, which has not yet received authorisation in the U.S. Last week, European regulators said they found a possible link between the shots and a very rare type of blood clot that occurs together with low blood platelets, one that seems to occur more in younger people.

The European Medicines Agency stressed that the benefits of receiving the vaccine outweigh the risks for most people. But several countries have imposed limits on who can receive the vaccine; Britain recommended that people under 30 be offered alternatives.

But the J&J and AstraZeneca vaccines are made with the same technology. Leading COVID-19 vaccines train the body to recognize the spike protein that coats the outer surface of the coronavirus. But the J&J and AstraZeneca vaccines use a cold virus, called an adenovirus, to carry the spike gene into the body. J&J uses a human adenovirus to create its vaccine while AstraZeneca uses a chimpanzee version.

The announcement hit US stock markets immediately, with Dow futures falling almost 200 points just over two hours before the opening bell. Shares of Johnson & Johnson dropped almost 3 per cent.

(With inputs from AP)

Posted By: Aalok Sensharma