Boosters, convalescent plasma, long-term effects, and other COVID-19 news

Plans to provide booster doses for the Pfizer-BioNTech and Moderna mRNA COVID-19 vaccines were announced by representatives of the CDC, FDA, NIH, and other government entities on Aug. 18. The joint statement said that the officials have concluded that a booster shot “will be needed to maximize vaccine-induced protection and prolong its durability” and “are prepared to offer booster shots for all Americans beginning the week of September 20 and starting 8 months after an individual's second dose.” On Aug. 23, the FDA gave its approval to the Pfizer-BioNTech COVID-19 vaccine, which the FDA's press release noted will now be marketed as Comirnaty, for the prevention of COVID-19 disease in patients 16 years of age and older. The emergency use authorization of the vaccine continues to apply to its administration to children 12 through 15 years of age and as a third dose to immunocompromised patients.

Convalescent plasma did not improve outcomes for outpatients with COVID-19, according to a trial published by the New England Journal of Medicine (NEJM) on Aug. 18. Stable patients seen in an ED with COVID-19 symptoms for less than a week who were at least 50 years of age or at high risk for disease progression were randomized to either convalescent plasma with a high titer of antibodies against SARS-CoV-2 (n=257) or placebo (n=254). The groups had similar outcomes for disease progression within 15 days, worst illness severity, and hospital-free days. Five patients in the plasma group and one patient in the placebo group died. The authors concluded that convalescent plasma did not work for the studied group but might still be useful with different dosing, patients, or timing. In other news regarding outpatients, the NIH's COVID-19 treatment guidelines were updated on Aug. 17 to support casirivimab plus imdevimab as postexposure prophylaxis for high-risk patients, in accordance with a recent emergency use authorization.

Another study, also published by NEJM on Aug. 18, looked at antibodies in survivors of SARS-CoV-1 who had received an mRNA SARS-CoV-2 vaccine and found that they are “high-level and broad-spectrum, capable of neutralizing not only known variants of concern but also sarbecoviruses that have been identified in bats and pangolins,” suggesting potential for “pan-sarbecovirus vaccine strategy.”

Long-term effects of COVID-19 were described by two recent studies. One, published by the Journal of Hospital Medicine on Aug. 18, used one-month follow-up surveys from 253 patients hospitalized in the U.S. Slightly more than half reported a new or worsened cardiopulmonary symptom, and 84.2% reported not feeling fully back to their previous level of functioning. Longer length of stay was associated with greater odds of cardiopulmonary symptoms and new disability. The authors also noted that previously published studies of community-acquired, non-COVID-19 pneumonia have similarly found after-effects to be common. The current study's results highlight the importance of recognizing both the long-term medical disabilities and the concomitant financial burdens commonly found in COVID-19 patients after discharge.

A Chinese study, published by Clinical Infectious Diseases on Aug. 14, provided a year of follow-up on 594 COVID-19 survivors. It found that 51.2% reported at least one symptom at three months after discharge, decreasing to 28.4% at a year. Lab tests and imaging showed abnormal liver and renal function and cardiovascular injury to be common, including electrocardiogram abnormalities in 49.8% of patients at one year.