The giant Johnson & Johnson company was forced to stop experiments on 60,000 patients, after a volunteer contracted an unknown disease, while people flocked around the world to develop a vaccine.
It is not clear yet whether the said patient was given a placebo or an experimental vaccine.
This comes about a month after the Oxford vaccine trials were stopped, after a British patient had a negative reaction.
The news was revealed by the company «AstraZeneca», which is working with researchers at the University of Oxford. Four days after this suspension, that is, by September 12, the British Medicines and Health Regulatory Authority confirmed that it is safe to resume experiments, which was considered a boost to efforts to develop the Corona vaccine.
Obstacles such as these, which have emerged at Oxford or at Johnson & Johnson, are commonplace during large-scale clinical trials.
Johnson & Johnson said in a statement, "We have temporarily stopped further doses on all our clinical trials for the Corona vaccine," adding, "According to our guidelines, the patient's disease is now being reviewed and evaluated."
And these experiments reached the third stage, meaning that the vaccine under testing has been given to thousands of people. It is one of six vaccines currently being tested in the United States.
The Johnson & Johnson vaccine requires patients to take one dose, while the other proposed vaccines, such as the "Pfizer and Moderna" vaccine, require two doses.
Dr. Willem Schafer, professor of infectious diseases at the College of Medicine at Vanderbilt University of America, says that the patient who was taking part in the tests may have developed a "neurological condition."
These experiments are taking place in the United States, and US President Donald Trump has repeatedly announced that the vaccine will be ready by the US elections, on November 3, or after.
But despite this, health officials in the United States previously indicated that the vaccine will not be ready until next spring.
British Health Minister Matt Hancock had previously announced that there was still hope that the vaccine would be ready this year, but he admitted that it was more likely to appear at the beginning of next year.