NEJM Study: Pfizer’s Paxlovid Reduces COVID-19 Death by 81% in Older Adults, Not Effective in Younger Patients
Pfizer’s Paxlovid, an oral antiviral, has been found to reduce the mortality rate in older adults.

Pfizer’s COVID-19 oral antiviral Paxlovid was found to reduce the mortality rate among people over the age of 65 by 81% in a new Israeli study published Wednesday in the New England Journal of Medicine. However, the study also found no significant benefit of the drug in patients aged 64 and younger.

It is the first peer-reviewed study on the effectiveness of the drug in real-world conditions, one of its lead researchers told Health Policy Watch

The study also differs from the Pfizer clinical trials on the drug that were conducted during the Delta wave, and on patients who were unvaccinated.

The Israeli study took place during the Omicron wave, and the majority of patients had been fully vaccinated with three jabs of the Pfizer Covid-19 vaccine.

The study is peer-reviewed and a fuller version of data first published in June on the Research Gate Platform. 

The researchers also found a 73% reduction in hospitalization rate compared to the control group. 

Hospitalization and Mortality Rates


To arrive at their results, the team of researchers analyzed Clalit electronic health records of high-risk patients over the age of 40 with advanced statistical methods between 9 January and 10 March of this year. During this period, 3,902 COVID-19 patients received Paxlovid via Clalit. 

The researchers compared the hospitalization and mortality rates among Covid patients who took the medicine and COVID patients who did not take the medicine (the control group).

The Pfizer clinical trial found that Paxlovid was 89% effective in patients at risk of serious illness, the company reported at the end of 2021. As noted, the Clalit rate of effectiveness was much lower.

However, Dr Ronen Arbel, Health Outcomes Researcher at Clalit Health Services and Sapir College, told Health Policy Watch that “if you want to compare apples to apples, you have to look at the minority of patients in our study who were unvaccinated and over the age of 65. If you look at them, the effectiveness is much more similar [to the Pfizer study]. 

“It is when you look at the majority of the patients, while the effect is significant, it is much smaller,” he said. 

Clalit has distributed more Paxlovid than any other health fund in Israel, according to Dr Doron Netzer, Chief Medical Officer of Clalit’s Community Health Division. 

In total, some 30,000 Israelis have received the drug. 

In March, a Medicines Patent Pool (MPP) announced it had signed agreements with 35 companies to manufacture generic versions of Paxlovid for distribution in 95 low- and middle-income countries.

But that came under fire almost immediately from medicines access groups as too little, too late. 

Reported Significant Reduction in Risk of Hospitalization and Death

In Israel, the drug is prescribed to COVID-19 patients aged 12 and older with mild to moderate symptoms who are at high risk for complications of Covid-19.

The treatment is given for five days, as close as possible to the date that a positive COVID-19 test is received. 

“The results if the study show unequivocally that treatment with Paxlovid significantly reduces the risk of hospitalization and death from Covid-19 in those over the age of 65,” Netzer said. “The decision of the Health Ministry to allow this treatment saved many lives.”

Earlier this month, the US Food and Drug Administration called on Pfizer to test another course of Paxlovid for those who have rebounded and tested positive after an initial dose.

It also requested that Pfizer hold a clinical trial to evaluate different durations of treatment in immunocompromised patients with mild-to-moderate disease, Health Policy Watch reported.

Pfizer told Bloomberg News that the trial protocol is expected to be finalized this month.

Arbel said that the Clalit study did not examine these questions due to limitations in its data. 

Image Credits: Pfizer , Bobbi-Jean MacKinnon.

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