The South African Health Products Regulatory Authority (Sahpra) gave the green light this week for Pfizer’s Paxlovid, an antiviral medication designed for Covid-19 that is highly successful at preventing severe disease and has been used in several countries.
Covid infections are quietly continuing to rise in SA, with the National Institute for Communicable Diseases’ epidemiological report, published in the third week of January, showing that 2 419 new Covid-19 cases had been reported since 14 January, escalating from 1 506 to 1 855 cases over a fortnight.
Paxlovid treats mild to moderate Covid-19 in adults who do not need supplemental oxygen but are at increased risk for progression to severe Covid, like the elderly and people with high-risk comorbidities.
The Daily Maverick reports that the medication has an excellent track record in reducing the risk (a clinical trial to support an application for emergency use put this at an 89% reduction) of vulnerable people developing severe Covid-19.
However, it cannot be taken with a long list of medications, or with remedies like St John’s Wort, and can have severe or life-threatening side-effects. These medicines include anti-rejection drugs for organ recipients, some medications for heart arrhythmias, some blood thinners, and some medication for high cholesterol.
Paxlovid comprises tablets for a five-day oral treatment regimen, with twice daily doses. The treatment consists of two antivirals: nirmatrelvir, which inhibits a key enzyme needed by the virus to make more virus particles, rendering it unable to enter healthy cells; and ritonavir, a booster.
Side-effects include hypersensitivity reactions, diarrhoea, vomiting and altered taste.
In December, the US Centre for Disease Control (CDC) reported that people taking Paxlovid within five days of being diagnosed with Covid-19 had a 51% lower hospital admission rate in the next month. The study included both vaccinated people and people who had a prior infection.
It is effective against the highly contagious Omicron variant, which is still the dominant variant in SA. BQ.1 and its sublineages increased in prevalence in October (6%), November (18%) and December (46%) and are the dominant Omicron lineage in January (51%).
XBB.1.5 was detected in December 2022 and January 2023 but only in 20 samples from the Free State, Gauteng, KwaZulu-Natal and the Western Cape. This variant has been described as the most transmissible version of Omicron yet.
Daily Maverick article – Covid-19 drug Paxlovid registered for use in South Africa (Open access)
See more from MedicalBrief archives:
Pfizer: Paxlovid fails to prevent COVID in members of same household
Paxlovid as a treatment for long COVID
Pfizer’s anti-COVID oral tablets show robust efficacy
Pfizer to deliver generic version of its COVID pill to 95 countries