SARS-CoV-2 mutations: The catalyst for a Covid-19 endemic?

GlobalData Healthcare 18th February 2021 (Last Updated February 18th, 2021 09:15)

SARS-CoV-2 mutations: The catalyst for a Covid-19 endemic?
On 8 February 2021, South Africa made headlines when it announced that it would be suspending AstraZeneca’s Covid-19 vaccine (AZD1222). Credit: Shutterstock.

The recent variant of the SARS-CoV-2 virus in South Africa (B.1.351) underscores a critical weakness in combatting the Covid-19 epidemic and may prolong it indefinitely. According to GlobalData, as of 16 February 2021, there have been over 109,134,000 confirmed infections since the pandemic began—and over 33,779,000 of them are active. As these numbers continue to trend upwards, so will the number of mutations, increasing the probability of more gain-of-function mutations, which can result in more strains like B.1.351.

On 8 February 2021, South Africa made headlines when it announced that it would be suspending AstraZeneca’s Covid-19 vaccine (AZD1222). According to Jon Cohen of Science Magazine, the vaccine’s efficacy was below 25% in the country (of which 90% of cases are the B.1.351 variant) and thus did not meet the minimum international standards for emergency use. This news came on the same day a World Health Organization (WHO) panel met to recommend its use, citing 63% efficacy, according to a guidance document on the AZD1222 vaccine released on 10 February 2021. Such disparity in efficacy figures suggests that the South African SARS-CoV-2 variant can effectively evade neutralising antibodies produced by the AZD1222 vaccine. While other vaccines may be effective against this strain, it does not exclude the possibility that such efficacy may not be the case for future strains. This outcome may prolong the epidemic into an endemic (much like the flu) as herd immunity will be difficult, if not impossible, to reach without properly working vaccines.

The possibility of this eventuality has led to calls for the adage that “no one is safe until everyone is safe.” Yet, despite these calls, according to Clair Felter of the Council on Foreign Relations, it will likely take years for most of the world’s population to get vaccinated. Given that a September article in Nature by Ewen Callaway estimates that the SARS-CoV-2 virus mutates at about half the rate of the virus that causes influenza, such a lag indicates that there will likely be many future mutations due to the large global prevalence already. The implications of this trend are notable as increases in gain-of-function mutations may also make the virus more virulent, which can increase the overall prevalence of cases simultaneously while making it easier to contract the virus, leading to a vicious cycle of infection, and further accelerate its spread.

To mitigate this, efforts to reduce the spread of the virus are imperative, as the only way to prevent the virus from mutating is by preventing infection altogether. Otherwise, the need for future booster shots (as is the case for the flu) may become exceedingly likely to prevent future variants from infecting individuals. If this is the case, then the pandemic might just become a new normal like the flu, where, according to GlobalData, 535,960,976 vaccines will be distributed in 2021 to keep the flu in check—let alone eradicate it.