The Covid-19 pandemic has affected every corner of the planet, and the outlook for overcoming it now depends upon the efficacy and availability of vaccines.
It has been more than a year since the World Health Organization declared Covid-19 a pandemic. Looking back, it has been an extraordinary period in all our lives. Hundreds of millions of people have been infected by the SARS-CoV-2 virus, and almost four million have succumbed to the disease. Our world has changed. But the devastation of the pandemic has also given rise to unprecedented scientific advancement, and we have risen to the challenge. In less than a year, several highly effective Covid-19 vaccines have been developed, approved and delivered. Mass vaccination is well advanced in many parts of the US and Europe, and concerted efforts from rich countries to help vaccinate the rest of the world are crucial in the race to bring the pandemic and variant epidemic outbreaks to an end.
The pandemic is as fast moving as the response. The first vaccines have succeeded in halting its progress, but we now face rapidly emerging variants and the likelihood that boosters will be needed to maintain protection.
Yet whilst populations are being vaccinated as quickly as vaccines can be produced, the virus is also adapting and mutating. Many variants have been detected, although thankfully most are inconsequential. However, some mutations are causing more concern. They are more infectious or more harmful, or both. Some have been shown to reduce the effectiveness of the current cohort of vaccines and treatment, and they could potentially derail the trajectory for returning to normality.
Although some recent Covid-19 variants can reduce vaccine effectiveness against infection, the current cohort of vaccines by and large still offers protection against severe illness and hospitalisation. Encouraging results from booster vaccine studies show that these vaccines raise the level of neutralising antibodies and could provide a broad spectrum of protection against several variants and any waning of immunity. Booster vaccines can also be developed relatively quickly, and more research has started on predicting and combatting the emergence of future variants. Potentially variant-agnostic oral antiviral drugs could also add another weapon to the antiviral arsenal.
This Insight attempts to provide a comprehensive review of current known Variants of Concern, booster vaccines and the future outlook for the pandemic.