It is true that few cases have been reported, but it is not known how many have gone unreported...No state keeps reliable statistics.
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America's Centers for Disease Control and Prevention and Food and Drug Administration reported that they are investigating unusual clots in six women that occurred 6 to 13 days after vaccination. The clots formed in the veins draining blood from the brain and occurred along with a low platelet count. All six cases involved women between the ages of 18 and 48. U.S. federal distribution channels, including mass vaccination sites, will halt use of the J&J vaccine.
Recommended, That people given the J&J vaccine who experience severe headache, abdominal pain, leg pain, or shortness of breath within three weeks after receiving the shot should contact their doctor.
Johnson & Johnson said, That he was aware of reports of "thromboembolic events" or blood clots, but no link to the vaccine was established.
"We are aware that thromboembolic events, including thrombocytopenia, have been reported with Covid-19 vaccines," Johnson & Johnson said in a statement. "At this time, a clear causal relationship between these rare events and the Janssen Covid-19 vaccine has not been established."
Source:
https://apnews.com/article/us-pause-j-and-j-vaccine-blood-clot-reports-2dde2aacf486bab59844ef907a28cbce
More than 6.8 million doses of Johnson & Johnson vaccine have already been administered in the United States, along with tens of millions of doses of vaccines made by Pfizer-BioNTech and Moderna.
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The question is whether this clotting occurs more frequently in vaccinated individuals than in unvaccinated ones.