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$1,650 COVID-19 treatment called into question after major study

LOS ANGELES — A new study of over 1.6 million older adults has found that the COVID-19 antiviral drug Paxlovid does not significantly reduce COVID-19-related hospitalizations or deaths in vaccinated seniors. The findings challenge current treatment practices and raise questions about the medication’s $1,650 price tag.

Researchers at UCLA and the University of Toronto discovered that even when Paxlovid prescriptions more than doubled among adults over 70, there was no significant reduction in COVID-related hospitalizations or deaths compared to similar patients who had limited access to the drug.

“Our study effectively rules out the notion that Paxlovid causes large reductions in COVID-19 hospitalization in vaccinated older adults,” said lead author Dr. John Mafi, an associate professor at UCLA, in a statement. “While we cannot rule out a small reduction in COVID-19 hospitalization, our results indicate that at best, Paxlovid’s potential effect on COVID-19 hospitalization among vaccinated older adults is four times weaker than the effect originally reported in Pfizer’s 2022 clinical trial.”

Since its emergency authorization in late 2021, Paxlovid has been a cornerstone of COVID-19 treatment. The medication combines two antiviral drugs—nirmatrelvir and ritonavir—that work together to prevent the coronavirus from replicating in the body. When taken within five days of symptom onset, it was initially shown to dramatically reduce the risk of severe illness in unvaccinated people.

But the landscape of COVID-19 treatment has changed significantly since those early studies. Most people, especially older adults, are now vaccinated against the virus. This raised an important question: Would Paxlovid provide the same benefits for vaccinated individuals?

The research team took advantage of a unique situation in Ontario, Canada, where health officials had restricted Paxlovid access to people 70 and older who tested positive for COVID-19, unless they had specific risk factors. This created a natural experiment, allowing researchers to compare health outcomes between similar groups of people who either did or didn’t have easy access to the medication.

Looking at data from April through November 2022, they found that Paxlovid prescriptions jumped from 106 to 228 per 100,000 people per month when patients crossed the age-70 threshold. However, this dramatic increase in medication access didn’t lead to better outcomes. COVID-19 hospitalization rates were nearly identical: 42.9 per 100,000 per month for those over 70, compared to 39.5 per 100,000 for those just under 70. Death rates showed similar patterns.

These findings, published in JAMA, have significant implications for healthcare systems worldwide. With Paxlovid costing approximately $1,650 per treatment course, the widespread prescription of this medication in populations where it may not provide meaningful benefit raises concerns about healthcare resource allocation.

The results also highlight how medical treatments can have different effects in different populations. While Paxlovid showed clear benefits in unvaccinated, middle-aged adults during its initial trials, these benefits appear greatly diminished in vaccinated seniors. This pattern underscores the importance of continued research as treatments are rolled out to broader populations.

“Since the study found no significant effect on COVID-19 hospitalizations and deaths among vaccinated older adults, our findings underscore the urgent need for further randomized clinical trials investigating Paxlovid’s effects in higher-risk populations, such as older subgroups who are frail or immunosuppressed,” said Dr. Katherine Kahn, the study’s senior author.

The research also sheds light on the evolving nature of COVID-19 treatment. Early in the pandemic, when vaccines weren’t available, antiviral medications like Paxlovid played a crucial role in preventing severe illness. Now, with widespread vaccination and immunity from previous infections, the benefits of these medications may be more limited.

This doesn’t mean Paxlovid has no role in COVID-19 treatment. Rather, the findings suggest that healthcare providers may need to be more selective about prescribing it. Certain high-risk groups, such as immunocompromised patients or those with multiple underlying health conditions, might still benefit significantly from the medication.

The study’s findings align with a recent trend in COVID-19 research showing that treatments highly effective in unvaccinated populations may have reduced benefits in vaccinated individuals. This highlights the need for treatment recommendations that take vaccination status into account.

“Because access to Paxlovid in this study was in effect randomized for those close to the age 70 cutoff, our results are unlikely to reflect unobserved confounding,” explained study co-author Sitaram Vangala, biostatistician in the Department of Medicine Statistics Core. “This may explain why our results align with the recent negative 2024 clinical trial among vaccinated middle-aged adults, but not with observational studies showing that Paxlovid is associated with large reductions in hospitalization and mortality in vaccinated older adults.”