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New COVID Antivirals Do Not Replace the Need to Vaccinate

With the advent of new COVID drugs comes the fear that people will opt out of vaccination altogether

Molnupiravir capsule antiviral drug pill for anti Corona virus(COVID-19) developed by Merck and Co.

Molnupiravir is one of two oral antivirals that could soon be available to treat COVID. Experts say that having the pills is important, but that people should still get vaccinated.

Throughout the COVID pandemic, what has been missing from our medical tool kit is an easy-to-take treatment that keeps people out of the hospital. Yet, within the next few weeks, we will have two new antivirals: Merck’s molnupiravir and Pfizer’s Paxlovid. As part of the unimaginable speed that has characterized the medical countermeasure response to COVID, the advent of two highly effective treatments for COVID is nothing short of game-changing.

But given that nearly 30 percent of adults are not fully vaccinated against COVID, it is natural to wonder if having these highly effective oral drugs will diminish the value or role of COVID vaccines in our response. There is a real fear being voiced by public health practitioners that if highly effective treatments stand at the ready, people who have so far shunned the vaccine will likely never get vaccinated. That they will get COVID is likely inevitable, prolonging the pandemic, continuing to endanger high-risk individuals, and further taxing our hospitals and their staff.

This is troubling, because as those of us in the world of infectious disease know from centuries of past experience with pathogens, preventing infection is always better than treating it. Always. This is especially true for COVID, when we can prevent infection easily with safe and highly effective vaccines; in clinical trial data Pfizer’s vaccine was 95 percent effective in preventing infection in adults, Moderna’s vaccine was 94 percent effective, and Johnson & Johnson’s vaccine was 66 percent effective. And all COVID vaccines are extremely effective at preventing serious illness, hospitalization and death. To many of us, this matters more than preventing infection.


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The most valuable asset we have in the fight against COVID-19 is still unequivocally vaccination, and the presence of effective drugs doesn’t change that.

The concern that unvaccinated people will never get vaccinated if we now have effective treatments for COVID is not new; a similar scenario has already occurred with monoclonal antibodies authorized to treat people who are either infected or who have been exposed to SARS-CoV-2, the COVID virus. These medications have been effective in preventing hospitalization in those early cases and exposures.

In Florida, these products are readily available, and some have practically promoted the antibodies as vaccine alternatives. Many unvaccinated people have taken them, and they likely have avoided serious illness. Paradoxically, some people who are averse to vaccines and the cutting-edge science behind them welcome monoclonal antibodies that are also the result of cutting-edge science. This is likely because people change their conceptions of risk once they find out they have COVID. When they get sick, they become more willing to accept interventions than when they are healthy; the risk/benefit calculation changes for many of them.

With the prospect that an unvaccinated person can take a pill rather than injectable or infusible antibody treatments, this type of thinking might become even more prevalent. Yet however compelling this line of reasoning might seem at first glance, it is wrong. We must enhance our efforts to get unvaccinated people vaccinated by proactively dispelling the myths the anti-vaccine crowd spreads, and by enlisting primary care physicians—who are greatly trusted by their patients—to counsel hesitant people.

COVID, especially in unvaccinated people, is something to avoid even for those who are at low risk for serious disease. Whereas in high-risk groups, COVID-19 hospitalizes and can kill, in nearly everyone it is disruptive and contagious. In a small proportion of those infected, it causes what’s called long COVID—lingering symptoms that interfere with daily life. A positive case invariably requires a local public health official to notify close contacts. That person who is infected has to self-isolate and get tested repeatedly. And for people who are significantly exposed, they face days of quarantine.

Vaccines unquestionably and significantly decrease the likelihood of any part of this negative cascade ever happening.

COVID antivirals, like monoclonal antibodies before them, are not a substitute for vaccinations. They are a complement to vaccines, and they serve an important function. When the influenza antiviral Tamiflu became available, it did not diminish the importance of the flu vaccine. People still get flu vaccines, and if they get sick (regardless of whether they got the flu shot), they are sick for fewer days and less likely to be hospitalized or experience complications because of Tamiflu.

These new COVID antivirals will be used in any eligible person, regardless of vaccination status, and clinicians will greatly value the drugs, as they do monoclonal antibodies. In addition, because remdesivir, the only available treatment for COVID, requires hospitalization and dedicated space in a hospital, having these oral antivirals helps us achieve one of the most important goals of managing the pandemic: preserving hospital capacity.

Once they are available in the U.S., these antivirals (United Kingdom regulators have approved molnupiravir for use there), our COVID-19 armamentarium will be robust. We will have hundreds of diagnostic tests, multiple treatments and proven vaccines. These additional tools will continue to get us closer to the off-ramp of the pandemic in the U.S.

That this disease can be transformed within less than two years into a vaccine-preventable infection that can be diagnosed at home and is amenable to treatment with monoclonal antibodies and, soon, oral antivirals is truly remarkable.

Even so, COVID is not a disease that will be eliminated. It is an efficiently spreading respiratory virus with an animal reservoir, and it spreads quickly, even before people have symptoms. The virus is here to stay, but we can keep adding tools to manage its consequences better. As the virus transitions to something endemic, like influenza, the aim is to keep it from hospitalizing and killing people. It is a crucial task to develop a menu of medical countermeasures, including treatments. But, by any analysis, vaccines remain the chief tool needed to accomplish this task.

In the battle against COVID, we still need to prioritize vaccination, even as optimism abounds with the arrival of oral antivirals. It is inestimably valuable that there now exist multiple treatment options to forestall severe disease in infected individuals, but, without a doubt, it is still better to prevent as many infections as we can.

Amesh Adalja is a senior scholar at the Johns Hopkins University Center for Health Security. His work is focused on emerging infectious disease, pandemic preparedness and biosecurity. He holds an M.D. from the American University of the Caribbean.

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