Pfizer's (PFE  ) experimental, an antiviral pill for COVID-19 reduced rates of death and hospitalization for 90% of adults. In an interview with CNBC, former U.S. Centers for Disease Control and Prevention (CDC) chief Dr. Scott Gottlieb heralded the breakthrough and said that the pill could mark the "end of the pandemic".

The pill is a game changer because most current treatments for COVID-19 treatments require an IV or injection. Merck (MRK  ) has another pill in the contention that already received approval in the U.K. and is under consideration by the U.S. Food and Drug Administration (FDA). However, Merck's shares fell nearly 10% as Pfizer's pill delivered better results. In contrast, Merck's pill showed about a 50% reduction in deaths and hospitalizations.

Pfizer is looking to get authorization for the pill from the FDA and international regulators as soon as possible. It's expected that the FDA could grant it emergency authorization due to the impressive results within weeks or months.

In addition to vaccinations and monoclonal antibody treatments, it's believed that an at-home pill to treat COVID-19 that could ease symptoms, accelerate recovery, and keep people out of the hospitals, is the final step in ending the pandemic. It would make the treatment of COVID-19 similar to other infectious diseases where such early-stage treatments are available to reduce the disease's severity.

In a sense, the current pill is following a similar procedure as Pfizer's vaccine which gained quick, emergency authorization due to the fantastic results of clinical trials. For its pill, Pfizer conducted a preliminary study of 775 adults. Patients who received the Pfizer antiviral pill along with another antiviral shortly after showing COVID-19 symptoms had an 89% reduction in their combined rate of hospitalization or death after a month, compared to patients taking a dummy pill. Fewer than 1% of patients taking the drug needed to be hospitalized and no one died. In the comparison group, 7% were hospitalized and there were seven deaths.

Study participants were unvaccinated, with mild-to-moderate COVID-19, and were considered high risk for hospitalization due to health problems like obesity, diabetes, or heart disease. Treatment began within three to five days of initial symptoms and lasted for five days. Patients who received the drug earlier showed slightly better results, underscoring the need for speedy testing and treatment. The company didn't include many details of side effects but reported that about 20% of patients experienced some.

The trial was halted by a group of independent medical experts due to its high and extraordinary rate of success as the results show a clear benefit. So far, the data has not been published for outside review.

This treatment is considered by some to be the "beginning of the end of the pandemic" because it will provide more protection for unvaccinated people. Additionally given incidences of breakthrough cases in vaccinated people and the potential for new strains of the virus, this is simply another powerful toolkit in the fight against the virus.