Editor's note: Because information on COVID-19 continues to evolve, this content may have changed since we went to press in mid-March.

Transmission

Figure. Fearing their lot of COVID-19 vaccines would expire while they were stuck in traffic in a snowstorm, public health workers in Cave Junction, Oregon, walked from car to car offering vaccines to stranded motorists. Photo by Josephine County Public Health Department, via Twitter.

* Identifying and isolating people with symptomatic COVID-19 alone will not control the ongoing spread of SARS-CoV-2, according to a study in the January 4 JAMA Network Open. The study assessed the relative amount of transmission from presymptomatic, never symptomatic, and symptomatic individuals across a range of scenarios. Results showed that at least 50% of new SARS-CoV-2 infections were estimated to have originated from exposure to individuals without symptoms, suggesting that mask wearing, hand hygiene, social distancing, and strategic testing of asymptomatic people are needed to slow the spread until vaccines are more widely available and used.

Treatment

* Convalescent plasma administered to patients hospitalized with SARS-CoV-2 has been unsuccessful, but authors of a new study suggest that this may be because the antibodies should be administered earlier in the course of the illness. The study, published in the February 18 New England Journal of Medicine, found that early administration (within 72 hours) of high-titer convalescent plasma to mildly ill infected older adults reduced the progression of COVID-19 to severe respiratory disease by 48%, suggesting that earlier intervention may be critical for efficacy.

Mortality

* COVID-19 mortality rates declined over the first six months of the pandemic, according to a study published online on December 22 in JAMA Internal Medicine. Using data from a large U.S. health insurer, researchers assessed nearly 28,000 adults admitted with COVID-19 across 400 hospitals from January through June 2020. They found that the mean rate of inpatient mortality or hospice referral within 30 days of hospital admission decreased from 17% to 9% over the study period. Mortality rates in hospitals were lower when the prevalence of COVID-19 in their surrounding communities was lower.

Global Initiatives

* South Africa, with 32,429 cases, has the highest number of health care workers on the African continent infected with COVID-19, according to the World Health Organization. The COVID-19 Africa Action Network for Nurses and Nurse-Midwives has partnered with Direct Relief and the global medical technology company BD to enhance the safety of nurses, nurse midwives, and other health care workers on the front lines of the pandemic in Africa. The support will enable an increase in the local production of reusable, evidence-based medical masks. The partnership will also allow new projects to be rolled out in the southern and eastern regions of Africa with a goal of delivering more than 1 million medical masks for key health care workers.

Vaccination

* At the time of this writing, more than 70 million people in the United States have received one or more doses of a COVID-19 vaccine. While the rollout started off slowly, Dr. Anthony Fauci on February 1 announced a series of measures by the Biden administration to speed things up, including the purchase of 200 million more vaccine doses and mobilizing the Federal Emergency Management Agency and the military to help with distribution.