New oral COVID-19 antiviral treatment – a step in the right direction

By Dr. Noorali Bharwani

Scientists around the world are working hard to get one step ahead of the various COVID-19 viruses. Is victory in sight?

We have the highly infectious Omicron coronavirus variant causing less severe disease than the Delta strain but it remains a dangerous virus, particularly for those who are unvaccinated. The Omicron variant is the dominant strain in Alberta.

Like other variants, Omicron spreads from the nose and mouth through respiratory droplets at close range and through virus particles that float through the air and can stay suspended for quite a while, especially in places with poor ventilation. That is why use of face masks or coverings has been recommended in public settings to minimise the risk of transmissions.

Then there is Omicron subvariant BA.2. That raises more questions about the evolution of virus behind COVID-19. Alberta recently reported three cases of BA.2 variant. By the time you read this there may be more. Denmark recently reported a surge of BA.2 infections.

Omicron infections make up more than 90 per cent of Canada's recent cases - and nearly all of those remain BA.1. But BA.2 infections totalled around one per cent of reported cases in early January.

We should not forget Alpha, Beta, Gamma and Delta variants. They are still around. We should continue to practice what reduces our risk of getting seriously ill with COVID-19 infection. Vaccination does not provide hundred per cent protection but it can reduce the risk of getting seriously ill. Vast majority of the patients with COVID-19 infection in the ICU are not vaccinated.

Here is the good news.

The new oral COVID-19 antiviral treatment is now available in Canada. This is Pfizer's antiviral Paxlovid, which can be given to COVID-19 patients who are at high-risk of severe illness from the virus. A doctor has to prescribe the pills.

Paxlovid combines a new drug developed by Pfizer, Nirmatrelvir, with an existing antiretroviral drug named Ritonavir, a low-dose HIV drug that helps Nirmatrelvir remain active in the body longer.

The treatment comprises three pills - two of Nirmatrelvir and one of Ritonavir - taken at home twice a day for five days. That is 30 pills over five days. A person should start taking Paxlovid no more than five days after symptoms start. Hopefully, this will take pressure off the health-care system.

Health Canada has authorized the use of these drugs in high-risk adults (18 and older) with mild or moderate confirmed cases of COVID-19 patients. People who are immunocompromised, 80 years of age and over, or who may not have access to health care because of geographical or socioeconomic concerns are first in line - regardless of vaccination status.

Health Canada has warned the product should not be used while a patient is on any of a long list of other drugs, including common medications used to treat erectile dysfunction, high cholesterol and seasonal allergies, among others.

Here are few things to remember:

• The treatment must be started within five days of the onset of symptoms.

• It is designed to help the body fight off infection and shorten the period of illness.

• It has been found highly effective - Paxlovid reduced the risk of hospitalization or death by 89 per cent compared to a placebo.

• The treatment is likely to work against the Omicron variant.

• Receiving the treatment does not exempt people from isolation requirements, and is not an alternative to vaccination.

• These antiviral drugs are not a replacement for vaccines, which remain the best way to keep people out of hospital. Statistics show unvaccinated people are 19 times more likely to be hospitalized with COVID-19 than fully vaccinated people.

Coronaviruses die very quickly when exposed to the UV light in sunlight. The viruses survive longest when the temperature is at room temperature or lower, and when the relative humidity is low (<50 per cent).

We know most transmissions occur indoor. We should continue with preventive measures - physical distancing, quarantining, ventilation of indoor spaces, covering coughs and sneezes, hand washing, and keeping unwashed hands away from the face.

Take care and be safe.