Washington (TIP): Trust in the safety of Johnson & Johnson’s Covid-19 vaccine has plunged 15 percentage points among Americans after federal health agencies recommended a “pause” in its use following blood clot cases, according to a new poll. Adults who said they believed the single-dose shot was safe dropped from 52 per cent before the pause was announced on Tuesday to 37 per cent afterward, Xinhua news agency quoted the poll conducted by the global opinion and data firm YouGov along with The Economist.

The poll was released on Thursday, April 15. Respondents who felt the Johnson & Johnson vaccine “unsafe” increased from 26 per cent to 39 percent.

Americans broadly trusted the other two vaccines approved in the US, with 59 per cent of respondents saying they thought the Moderna vaccine was safe and 58 per cent trusting the safety of the Pfizer vaccine.

The US Centers for Disease Control and Prevention and the Food and Drug Administration recommended halting the use of Johnson & Johnson’s Covid-19 vaccine on Tuesday, after rare blood clot cases emerged in six recipients.

In these cases, a type of blood clot called cerebral venous sinus thrombosis was seen in combination with low levels of blood platelets.

All six cases occurred among women between the ages of 18 and 48, and symptoms occurred 6 to 13 days after vaccination.

3rd vax dose likely needed within 12

months: Pfizer CEO

Pfizer Chief Executive Officer Albert Bourla said people will likely need a third dose of the Pfizer/BioNTech Covid-19 vaccine within 12 months of getting fully inoculated.

Bourla told CNBC News on Thursday that it is possible people will need to get vaccinated against the coronavirus annually, reports Xinhua news agency.

“We need to see what would be the sequence, and for how often we need to do that, that remains to be seen,” he told CNBC.

“A likely scenario is that there will be likely a need for a third dose, somewhere between six and 12 months and then from there, there will be an annual re-vaccination, but all of that needs to be confirmed. And again, the variants will play a key role,” he said.

Pfizer said earlier this month that its Covid-19 vaccine was more than 91 per cent effective at protecting against the coronavirus, and more than 95 per cent effective against severe disease up to six months after the second dose.

The data was based on more than 12,000 vaccinated participants.

Researchers are still working on how long protection against the virus lasts once individuals has been fully vaccinated.