Paxlovid is effective in reducing COVID-19 hospitalizations in vaccinated adults aged 50 years and older

However, little was known at the time whether Paxlovid could significantly benefit vaccinated people, or those infected with new variants of SARS-CoV-2 that did not prevail
in drug clinical trials.
By leveraging a large, well-validated repository of COVID-19 data in their system, researchers at Brigham Medical School at Massachusetts General Hospital confirmed that the drug was associated with
a 44 percent reduction in hospitalizations or deaths among highly vaccinated adults over the age of 50.

The findings, now published in the Annals of Internal Medicine, show that Paxlovid could even provide significant benefits to vaccinated patients diagnosed with COVID-19 in the outpatient, and contribute to ongoing efforts
to reduce COVID-19 hospitalizations during the projected winter surge.

"When Paxlovid was first used to treat COVID-19, providers and patients asked important questions about who might benefit most from this intervention, and in some cases possible complications," said
Scott Dryden-Peterson, MD, medical director and corresponding author of the Brigham COVID Outpatient Treatment at Massachusetts General Hospital 。 "Low hospitalization or mortality was observed in outpatients diagnosed with COVID-19 (1%), but we found that Paxlovid was still associated with
a proportional reduction in hospitalization risk of approximately 50% in patient groups at different baseline risk levels.
"

Dryden-Peterson and his team believe that the lower risk reductions seen in this study compared to clinical trials may be the result of a different context because the patients in this study had higher levels of prior immunity overall and therefore a lower
risk of developing severe disease.
However, in a small number of patients who received less than three doses of vaccination, hospitalizations were reduced by 81%, comparable
to the rates found in the original trial.
It is worth noting that among patients treated with Paxlovid, not a single hospitalization (69 in total) was attributed to "Fuyang", and in some patients this symptom showed initial relief
after the use of antiviral drugs.

To conduct the study, the researchers simulated a clinical trial in Paxlovid, using observational data
from nearly 45,000 patients diagnosed with COVID-19 in outpatient clinics from January to July 2022.
Of these patients, 28% were treated
with Paxlovid.
The researchers sought to maximize comparability between treatment and nontreatment groups in the study, as in prospective trials, taking into account a wide variety of factors, including age, comorbidities, vaccination history, race and ethnicity, and community disadvantage scores
.
This statistical granularity was achieved by using the Brigham Enclave of Massachusetts General Hospital, a repository that includes carefully validated information
about patients who tested positive for COVID-19 as well as negative controls.

"While prospective, randomized controlled trials are the gold standard for analyzing drug efficacy, in a pandemic setting, we have been challenged to provide rigorous data in less time to guide clinical care," said
Ann Woolley, MD, Master of Public Health, and senior author and associate clinical director of transplant infectious diseases at Brigham and Women's Hospital.

"The impetus for this study is the need to figure out how this therapy fits into Brigham Massachusetts General Hospital's response
to COVID-19.
This study, combined and building on existing systems, gives us a sense in MIT's Brigham System and Infectious Disease Clinical System that we are right
to prescribe Paxlovid to eligible patients.
”

Using data from Brigham Enclave at Massachusetts General Hospital, researchers can quickly assess the efficacy
of drugs after they are approved for use.
The results of this study were first released to the public in preprint form in June 2022 and incorporated into the CDC's guidance on the treatment of
COVID-19.
Other studies have confirmed Paxlovid's efficacy, but this study has the longest study period and has a very large, reliable, well-curated dataset
.

In the coming months, the authors expect Paxlovid to play a more important role in the fight against COVID-19, as there are currently no monoclonal antibody therapies in the United States that can effectively combat the circulating strain
of the SARS-CoV-2 virus.
In addition, the results of this study guide direct care
for high-risk populations.

The researchers found that the majority of COVID-19 hospitalizations during this study period were patients who were undiagnosed prior to admission, highlighting the importance of
removing barriers to early detection.
Among those outpatients diagnosed with COVID-19, the proportion of black or Latino patients using Paxlovid prescriptions was much lower, highlighting persistent disparities
in access to and provision of care.

Dryden-Peterson said: "This data is very helpful
in preparing us for the winter pandemic.
Our findings suggest that Paxlovid can save lives and that it can have a real impact
on keeping hospital beds available to treat other conditions.
" There is no chance that people will be hospitalized for COVID-19 unless they know they are positive, so we have been working hard to outreach, provide testing, and communicate with patients at highest risk to tell them they may benefit from Paxlovid or other antiviral treatment options
.
”

This article was provided by Brigham and Women's Hospital on December 13, 2022