Tip/Thought of the Day

Pfizer and Merck’s New AntiViral Drugs Promising As Pandemic Continues to Shift

Mid November brought about exciting news in the fight against Covid-19. This comes as a relief as news spread last week that deaths in 2021 have now surpassed those in 2020, with a total between the years totaling at more than 771,000 souls lost. While vaccines continue to be the first line of defense against the virus, the medical community has been working on a drug that can keep people out of the hospital within the first few days of infection. This can not only help combat the virus, but also work to ease the load on the nation’s first responders who are again facing a shortage of space and providers as the pandemic rages on. Two pharmaceutical companies, Merck and Pfizer have developed antivirals (Molnupiravir and Paxlovid, respectively) that will provide another tool in our arsenal against the Covid-19 virus. The medical community at large continues to spread the word- the most effective weapon against the virus is prevention via vaccination.

The vaccination rate in the United States continues to hover around 59%, as of November 24th, 2021. 74.1% of eligible people (5+) have received at least one shot, meaning that with the exception of those that received the Johnson and Johnson vaccine, which is a single dose vaccine, there is a significant gap in those that need to receive a second dose before being considered fully vaccinated against Covid-19. Researchers have said we need to reach a vaccination rate between 70-85% in order to reach herd immunity. With the level of people reaching full vaccination status seemingly at a standstill, many wonder if the introduction of the new antivirals will also continue to erode at the efforts to vaccinate more of the population. The concern mirrors those that came to light when monoclonal antibodies authorized to treat people who are either infected or who have been exposed Covid-19 were released earlier this year. If treatments existed that could prevent hospitalization or serious illness, what is the incentive for those opposed to the vaccine to purse vaccination against Covid-19?

Researchers are ironclad in their support that the fight against Covid-19 must include a variety of tools, with prevention being the first in line. Prevention and treatment must go hand in hand. It’s important to have treatments in case people fall ill, but it’s even better to prevent the disease in the first place,” Dr. Leana Wen, public health professor at George Washington University. She went on to explain to Fortune magazine, “Covid-19 oral treatments are an important component of how we must learn to live with the virus—though it does not replace preventing contracting the virus, and spreading it to others.”

The antivirals are seen as a second layer of protection against severe illness- “The sicker the patient, the less effective the drugs are in treating the illness,” explained Richard Plemper, a virologist at Georgia State University in Atlanta. He says the antivirals work best with the approach of “hit early, hit hard”. That the new antiviral drugs will be available through pharmacies nationwide will mean people can access them in those crucial first days of infection.

How does Merck’s Molnupiravir fight against the Covid-19 virus?

Developed by Merck and Ridgeback Therapeutics, Molnupiravir was released in October and in December, the FDA will review Merck’s application for emergency use of the drug. Molnupiravir reduced hospitalizations by 50% and prevented deaths entirely a large randomized clinical trial when it was given within five days of when symptoms began. The pill is given as a five-day course during which patients take a total of 40 pills.

Plemper explains the antiviral works through a process called “lethal mutagenesis”. “The virus essentially mutates itself to death.” And because the mutations accumulate randomly, it’s difficult for viruses to evolve resistance to molnupiravir, which is a a relief in a time when every new variation found across the globe has the potential to circumvent current vaccines if the mutation has adapted efficiently enough.

An external advisory committee partnering with the FDA is scheduled to meet Nov. 30, 2021 to discuss the safety and effectiveness of molnupiravir.

How does Pfizer’s Paxlovid antiviral work?

Paxlovid, developed by Pfeizer, was found to reduce the risk of hospitalization or death by 89% compared to placebo in non-hospitalized high-risk adults with COVID-19. According to their study, through day 28, no deaths were reported in patients who received the antiviral, compared to 10 deaths in those who received placebo.

The Pfizer drug, known as a protease inhibitor, is designed to block an enzyme the virus needs in order to multiply. When taken alongside a low dose of another antiviral pill called ritonavir, it stays in the body for longer. When Paxlovid was given to people at high risk of severe illness within three days of symptom onset, it reduced the rate of death and hospitalization by 89 percent compared with people given a placebo

In fact, results from the study on the efficacy of the drug, which is a a five-day regimen, were so promising that midway through, an independent committee monitoring the clinical trial recommended it be stopped early. Shortly after, Pfizer submitted data to the FDA in application for emergency use of Paxlovid. Sources confirmed that Pfizer is requesting authorization for people who are at increased risk of hospitalization due to age or underlying medical conditions. The clinical trial did not include people who fell sick after being vaccinated, but the FDA will decide on the final eligible population and usage of the drug.



People aged 5+ are now eligible for vaccines, and on November 19th, the FDA amended the emergency use authorizations for both the Moderna and Pfizer-BioNTech COVID-19 vaccines. Now, anybody 18+ is able to receive a single booster after completion of primary vaccination with any FDA-authorized or approved COVID-19 vaccine.

If you haven’t yet received your initial Covid-19 vaccination, we urge you to do so. The longer we wait to achieve herd immunity the more likely a variant will come into existence that overwhelms our current protections and puts us all back to square one. The delta variant is more virulent and infectious than the COVID strain that killed over a 1/2 million souls in this country. Now a new one -omicron- is evolving off our coastline, and possibly within our borders already, creating a similar concern. Treatments are an incredible addition to how we respond to this worldwide catastrophe. But vaccinations are the only way to stop it for good.

You can read more about the vaccines in our post, here. If you would like to find and schedule your Covid-19 vaccine or booster, click below. Pima County has also made walk-in clinics (no appointment needed) available to the public for both the primary vaccines and boosters- find locations here.


Sources:

-https://www.nature.com/articles/d41586-021-02783-1

-https://www.bbc.com/news/health-59178291

-https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-expands-eligibility-covid-19-vaccine-boosters

-https://www.google.com/amp/s/www.scientificamerican.com/article/new-covid-antivirals-do-not-replace-the-need-to-vaccinate/%3famp=true

-https://www.washingtonpost.com/health/2021/11/05/pfizer-covid-pill/

-https://www.webmd.com/lung/news/20211122/us-covid-deaths-2021-surpass-2020-total

-https://www.google.com/amp/s/fortune.com/2021/11/16/antiviral-covid-pills-dont-eliminate-the-need-to-get-vaccinated-doctors-say/amp/

-https://www.washingtonpost.com/health/2021/11/05/pfizer-covid-pill/

-https://www.npr.org/sections/health-shots/2021/02/03/963373971/a-rocky-road-on-the-way-to-herd-immunity-for-covid-19

-https://www.npr.org/sections/health-shots/2021/01/28/960901166/how-is-the-covid-19-vaccination-campaign-going-in-your-state

-https://www.pfizer.com/news/press-release/press-release-detail/pfizers-novel-covid-19-oral-antiviral-treatment-candidate

-https://www.washingtonpost.com/health/2021/11/16/pfizer-seeks-authorization-paxlovid/

-https://www.statnews.com/2021/11/15/8-lingering-questions-about-the-new-covid-pills-from-merck-and-pfizer/

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