Concerns over the AstraZeneca vaccine. Older people are happier. The week in Covid-19 news.


A handful of countries in Europe are shying away from the vaccine developed by AstraZeneca and the University of Oxford. Demark, Norway and Iceland said Thursday they would halt its use while European drug regulators examine the possibility of a link to blood-clotting issues. They emphasized that they were just being cautious and that there is no evidence of any causal link, and global health authorities confirmed support for the vaccine.

Bulgaria joined those countries on Friday, saying it would temporarily suspend inoculations with the AstraZeneca vaccine after the death of a woman a day after she received a shot (her autopsy found no traces of blood clots). And Thailand delayed its rollout of the vaccine, which was to begin Friday. The Democratic Republic of Congo has also delayed its rollout, Reuters reported.

Germany, France, Poland and Nigeria have said they would continue to administer the vaccine.

A senior adviser to the World Health Organization, Bruce Aylward, stressed in a news briefing on Friday that the W.H.O. had “great confidence” in AstraZeneca’s vaccine.

The vaccine has been authorized for use in more than 70 countries, but not the United States, where it is still going through clinical trials.

A shortfall in the supply of the AstraZeneca vaccine has fueled tensions within Europe and with European Union allies. AstraZeneca has asked the Biden administration to let it send unused American doses to the E.U.

Here’s what else were learned this week:

  • A new study found that older people managed to stay happier during the pandemic. During the study, those over 50 — independent of income or education, in national samples — experienced more positive emotions in a given day and fewer negative ones. The results of the study also helped answer an age old question: Do people somehow develop better coping skills as they age? They seem to.

  • An analysis of electronic medical records in California found that nearly a third of people who experience long-term symptoms from the coronavirus had not had any symptoms from their initial coronavirus infection through the 10 days after they tested positive.

  • Of over 200,000 people who were tested in city school buildings in New York City from October to December, only .4 percent of tests came back positive for the coronavirus, a remarkably lower virus transmission compared with the citywide rate of positive test results. Even when cases were detected, only .5 percent of school-based contacts who quarantined contracted the virus.