More than 10 million Americans had received their first dose of a Covid-19 vaccine as of Jan. 13, according to the U.S. Centers for Disease Control and Prevention, as the year-old pandemic roared on unchecked.

Johnson & Johnson is on track to roll out a single-shot coronavirus vaccine in March, and plans to have clear data on how effective it is by the end of January or early February, the U.S. healthcare company’s chief science officer said.

The second year of the Covid-19 pandemic may be tougher than the first given how the new coronavirus is spreading, especially in the northern hemisphere as more-infectious variants circulate, the World Health Organization (WHO) said.

China’s Sinovac Biotech defended the safety and efficacy of the company’s experimental Covid-19 vaccine, after researchers in Brazil released late-stage clinical data showing efficacy that was much lower than initially announced.

Immunity from Moderna Inc.’s Covid-19 vaccine should last at least a year, the company said at the J.P. Morgan Healthcare conference.

A roundup of scientific studies on the novel coronavirus and efforts to find treatments and vaccines includes research on Covid-19 patients who still have symptoms 6 months after falling ill.

As many as eight gorillas at the San Diego Zoo Safari Park were presumed to have contracted Covid-19 from a human handler after one of the animals tested positive, marking the first known transmission of the virus to apes, zoo officials said.

The United States lost more than 22,000 lives to Covid-19 for the week ended Jan. 10, setting a record for the second week in a row, as new cases also hit a weekly high.

Nearly 9 million Americans had been given their first Covid-19 vaccination dose as of Jan. 11, the U.S. Centers for Disease Control and Prevention said, as states scrambled to step up inoculations that have yet to slow the roaring pandemic.

Evidence continues to build for long-lasting immunity to Covid-19 following disease infection, with the publication of a new study showing a durable immune response as far as eight months after the initial onset of symptoms.