COVID-19: Single Dose of J&J Vaccine / Plasma / New Testing Requirement

By Kelly Young

Edited by Susan Sadoughi, MD, and Richard Saitz, MD, MPH, FACP, DFASAM

A single dose of Johnson & Johnson’s Ad26.COV2.S vaccine appears to be safe and induce an immune response in two age groups, according to interim results of a phase 1-2a trial published in the New England Journal of Medicine.

A total of 800 adults aged 18 to 55 or aged 65 and up were randomized to various combinations of low-dose or high-dose vaccines or placebo, given 56 days apart.

Adverse events were common, with fatigue, headache, myalgia, and injection-site pain reported most often. At day 29 after the first dose, the seroconversion rate was 99% or more in the younger cohort across dosing groups. Older vaccine recipients had a 96% seroconversion rate. At 57 days after the first dose, antibody titers had increased further.

Here are some other recent COVID-19 developments:

Plasma in nonventilated patients: Among hospitalized COVID-19 patients who don’t require mechanical ventilation, convalescent plasma with high antibody levels is associated with lower 30-day mortality than low-antibody-level plasma, according to a retrospective study in NEJM. Researchers examined outcomes in some 3100 adults hospitalized with COVID-19 who had at least one risk factor and were treated with convalescent plasma. Patients who received plasma with high anti-SARS-CoV-2 IgG antibody levels had a 30-day mortality rate of 22%, versus 30% among those in the low-titer group. Results were significant only among those who didn’t receive mechanical ventilation. Receiving plasma within 3 days of testing positive was associated with lower mortality rates than receiving it later.

New CDC testing requirement: All travelers boarding international flights to the U.S. must now have evidence of a negative COVID-19 test within 3 days before their flight or have documentation of recovery from COVID-19, the CDC announced on Tuesday. The agency recommends that passengers get tested again 3 to 5 days after their arrival in the U.S. and stay home for a week after traveling.