Reaction after US recommends pause for J&J COVID-19 vaccine

US federal health agencies on Tuesday recommended pausing the use of Johnson & Johnson's COVID-19 vaccine after six recipients developed a rare disorder involving blood clots, in a fresh setback to global efforts to tackle the pandemic.

Following are initial reactions:

Eleanor Riley, professor of immunology and infectious disease at the University of Edinburgh:.

"Whilst a causal link between COVID-19 vaccination, platelet abnormalities and blood clots has not, so far, been confirmed, the index of suspicion is rising that these rare cases may be triggered by the adenovirus component of the AstraZeneca and J&J vaccines.

"Whilst more data need to be collected, and the implications carefully considered, it remains the case that for the vast majority of people the risks associated with contracting COVID-19 far, far outweigh any risk of being vaccinated.

"Moreover, increasing awareness of the possibility of such side-effects means that they should be diagnosed more quickly and treated more successfully."

Dr. Amesh Adalja, infectious disease expert at the Johns Hopkins Center for Health Security in Baltimore.

"It's important to remember the 'hold' is only on federal vaccine sites - not all.

"I think this is a very low risk issue, even if causally linked to the vaccine: 6 cases with about 7 million doses (lower than the risk of clots with oral contraceptives) is not something to panic about, but the federal government has been overly cautious with many aspects of this pandemic.

"People are asking me if they should cancel their J&J vaccine appointments and I have told them not to. But I know many well and this will stall progress in controlling the pandemic."

Dr. William Schaffner, infectious disease doctor at Vanderbilt University Medical Center in Nashville.

"It shows our vaccine safety surveillance system is really working.

"We'll see what the further investigation by the FDA scientists and their external advisory committee show, but it is disturbing, of course," added Schaffner, who is a consultant to the Advisory Committee on Immunization Practices, which advises the Centers for Disease Control and Prevention.

"It certainly is concerning because the other vaccine in which this issue has been raised is also the other adenoviral vector vaccine, so you have to worry about that. That I think contributed to the very quick action of the CDC that is going to put the use of this vaccine on pause."

Dr. Robert Klugman at the UMass Memorial Medical Center in Massachusetts.

"The FDA recommendation to pause the administration of the Johnson and Johnson vaccine out of an abundance of caution makes sense in terms of the nature of the unusual and serious side-effect...

"While the incidence is very low, the severity and potential for brain damage and other blood clot-related injuries is of great concern."

Peter English, retired consultant in communicable disease control and an expert on vaccines:

This "would appear to be a highly precautionary move by the US' agencies...

"Even if all of the cases were caused by the vaccine, the risk of less than one in a million would have to be set against the benefits of protection from COVID-19 disease; a disease which, in itself, causes clotting in many cases.

"The call for a pause may dent confidence in vaccination. We must hope that, if it does, this will be temporary; and that the rapid action and openness will inspire confidence that vaccine safety is taken extremely seriously." strong text**