Study: COVID-19 vaccination protective against developing long COVID
A new review of 15 studies analyzed by the UK Health Security Agency (UKHSA) shows COVID-19 vaccination is protective against developing symptoms of long COVID, or symptoms lasting longer than 4 weeks after the initial infection.
The UKHSA said approximately 2% of people in the United Kingdom with COVID-19 have gone on to develop long COVID, with the most common symptoms being lingering fatigue, shortness of breath, and muscle and joint pain.
In a new rapid evidence review, the agency says eight studies show strong evidence that people who received two doses of COVID-19 vaccine are half as likely to develop long COVID. Another four studies demonstrate evidence that people who are vaccinated after receiving a long COVID diagnosis see their symptoms improve.
Mary Ramsay, MD, the head of Immunization at UKHSA, said in a press release, "These studies add to the potential benefits of receiving a full course of the COVID-19 vaccination. Vaccination is the best way to protect yourself from serious symptoms when you get infected and may also help to reduce the longer-term impact."
Feb 15 UKHSA rapid review
Feb 15 UKHSA press release
In a related development, the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) yesterday published in Clinical Microbiology and Infection new rapid guidelines for the assessment and treatment of patients with long COVID.
ESCMID recommends that patients experiencing respiratory symptoms at 3 months post initial infection may benefit from routine blood tests, chest imaging, and pulmonary function tests.
Feb 16 Clin Microbiol Infect paper
Nirmatrelvir-ritonavir cut risk of severe COVID by 89% in phase 2/3 trial
A phase 2/3 trial of 2,246 symptomatic, unvaccinated, high-risk COVID-19 outpatients finds that a combination of the antivirals nirmatrelvir and ritonavir lowered the risk of progression to severe illness by 89%.
Results of the trial, led by scientists from nirmatrelvir maker Pfizer, were published yesterday in the New England Journal of Medicine (NEJM).
The researchers randomly assigned 2,246 COVID-19 patients to receive either 300 milligrams (mg) of oral nirmatrelvir and 100 mg of ritonavir (1,120 patients) or a placebo every 12 hours for 5 days (1,126).
An interim analysis of 774 patients treated within 3 days of symptom onset showed that nirmatrelvir recipients' incidence of COVID-related hospitalization or death by day 28 was 6.32 percentage points lower than in the placebo group (95% confidence interval [CI], -9.04 to -3.59; relative risk reduction [RR], 89.1%).
Three of 389 nirmatrelvir patients (0.77%) were hospitalized, but none died. In contrast, 27 of 385 placebo patients (7.01%) were hospitalized, and 7 of them died.
The final analysis of 1,379 patients showed similar efficacy, with a difference in incidence of 5.81 percentage points (95% CI, -7.78 to -3.84) and a relative RR of 88.9%. All 13 deaths were among placebo recipients.
The SARS-CoV-2 viral load was lower in the nirmatrelvir than in the placebo group at day 5 of treatment. Treatment-emergent adverse events occurred in similar proportions in both groups (22.6% with nirmatrelvir vs 23.9% with placebo). Serious adverse events occurred in 1.6% of the nirmatrelvir group, compared with 6.6% in the placebo group, and adverse events leading to treatment discontinuation occurred in 2.1% vs. 4.2%, respectively.
Two adverse effects were reported more often in the nirmatrelvir than in the placebo group, with 5.6% versus 0.3% having an abnormal sense of taste and 3.1% versus 1.6% reporting diarrhea.
A related editorial by Eric Rubin, MD, PhD, NEJM editor-in-chief, and Deputy Editor Lindsey Baden, MD, said that the antiviral combination should be reserved for high-risk COVID-19 patients no more than 5 days after symptom onset. "Until we have a better idea of the potential for the emergence of resistance, we need to be good stewards of this medication," they wrote.
Feb 16 NEJM study and editorial