The health effects of Covid-19 not only can stretch for months but appear to increase the risk of death and chronic medical conditions, even in people who were never sick enough to be hospitalized, a large new study finds.

In the study, published Thursday in the journal Nature, researchers looked at medical records of more than 73,000 people across the United States whose coronavirus infections did not require hospitalization. Between one and six months after becoming infected, those patients had a significantly greater risk of death — 60 percent higher — than people who had not been infected with the virus.

BRUSSELS — Johnson & Johnson said Tuesday that it would resume the rollout of its coronavirus vaccine in Europe after the European Union’s drug regulator said that a warning should be added to the product indicating a possible link to rare blood clots, but that the shot’s benefits outweigh the risks.