The Covid-19 pandemic that began in late 2019 dramatically changed our world. Multiple coronavirus variants have emerged over the past three years, each bringing new waves of infection around the globe. With new variants continually arising, it can be hard to keep track of which one is currently dominant. This article provides an overview of the Covid variants we’ve seen so far and discusses which variant is causing the most infections currently.
A Brief History of Major Covid Variants
The original strain of SARS-CoV-2 emerged in Wuhan, China in November 2019. This strain, sometimes called the “wildtype,” quickly spread worldwide in early 2020, causing the first global wave of Covid-19 infections. However, viruses naturally mutate over time, leading to new variants.
The first notable variant, Alpha, was identified in the United Kingdom in late 2020. It became the predominant strain globally during the winter 2020-2021 surge. Alpha was more transmissible than the original Wuhan variant, though not necessarily more virulent.
The Beta variant emerged around the same time as Alpha but did not spread as efficiently. The Gamma variant surfaced in Brazil and also failed to displace Alpha. However, in mid-2021, the Delta variant arrived and changed the game.
Delta, first spotted in India in late 2020, was even more transmissible than Alpha. It soon took over as the dominant variant, driving a deadly summer 2021 wave in under-vaccinated countries like the United States. Vaccines still worked well against Delta but were slightly less effective than against the original strain.
Most recently, Omicron surfaced in November 2021 and proceeded to outcompete Delta within a matter of weeks. Omicron spreads faster than any previous variant and has extensive mutations that allow it to partially evade immunity. However, it typically causes less severe disease than earlier variants.
Omicron BA.5 Dominates Currently
Omicron remains the globally dominant Covid variant as of August 2022. However, Omicron has splintered into various sub-lineages, each with slightly different mutations. The Omicron subvariants BA.1 and BA.2 drove the massive winter 2022 Omicron surge. But they’ve since been displaced by newer Omicron sub-lineages like BA.4 and BA.5.
Currently, the Omicron subvariant BA.5 makes up the vast majority of sequenced Covid cases globally and in the United States. BA.5 accounted for nearly 90% of new infections in the US as of mid-August 2022. It is the most transmissible form of Covid we’ve seen yet.
BA.5 is capable of evading immunity from both previous infections and vaccinations. Even if you were infected with earlier Omicron subvariants like BA.1 or BA.2, reinfection with BA.5 is common. Vaccines still protect against severe disease and death, but efficacy against infection has dropped considerably.
The hyper-contagiousness of BA.5 has caused a summer 2022 surge in many countries, including the US, UK, and Europe after cases had started to decline earlier in the year. BA.5 spreads easily, even with warmer summer weather that typically slows coronavirus transmission. However, the combination of widespread prior immunity and improved treatments has kept hospitalization and death rates lower with BA.5 than in previous waves.
What Comes After BA.5?
Virologists keep a close eye out for new “variants of concern” that could someday overtake BA.5. Thus far, no variant has clearly shown a fitness advantage over BA.5. However, the coronavirus will continue evolving as long as it circulates widely.
One Omicron offshoot called BA.2.75 has gained attention recently. Nicknamed “Centaurus”, it was first detected in India in early May 2022. BA.2.75 carries additional mutations that could help it escape immunity from vaccination and previous infection. It has spread to over a dozen countries so far, including the US and UK. But BA.5 still outpaces it significantly.
Experts say BA.2.75 is worth tracking closely, though it is not an immediate global threat. Dr. Maria Van Kerkhove from the World Health Organization (WHO) commented, “We need to be paying attention to it, but it isn’t taking over or outcompeting BA.5.” Only time will tell whether BA.2.75 or another variant can finally dethrone BA.5.
In the meantime, getting boosted with the updated “bivalent” booster shots targeting Omicron released in fall 2022 remains our best defense. These vaccines provide protection tailored to the current circulating variants. Continued vigilance, surveillance, and vaccination will help blunt the impact of future variants when they inevitably arise.
Looking Ahead in the Pandemic
It has been a bumpy few years in the Covid-19 pandemic, marked by successive waves of new variants. While the future is unclear, Omicron and its offspring like BA.5 appear likely to dominate throughout 2022 and into 2023.
This prolonged Omicron wave comes at a time when many countries are moving past pandemic restrictions and trying to “live with the virus.” But we cannot afford to be complacent. New variants will continue to emerge, and some will be more dangerous than Omicron. Staying up to date on the latest variants and getting recommended boosters remains critical for protecting ourselves and our communities.
Though viruses keep mutating, human ingenuity and determination can still win out. Through science-backed prevention measures, developing new treatments, sharing vaccines globally, and learning to co-exist cautiously with COVID-19, we will find our way through the pandemic.
5 Key Questions about Current Covid Variants
1. Which variant is dominant globally right now?
The Omicron subvariant BA.5 currently causes around 90% of Covid-19 infections globally and in the United States. It is the most transmissible variant to date.
2. How is BA.5 different from earlier variants?
BA.5 is adept at evading immunity from vaccination and previous infection, even with other Omicron subvariants. It carries additional mutations that increase transmissibility and help it sneak past antibodies.
3. Will BA.5 cause another big Covid wave?
BA.5 is already fueling a summer 2022 surge in many countries. However, prior immunity has kept hospitalizations and deaths lower than in earlier waves. We may be headed towards “endemic” seasonal outbreaks with Omicron variants.
4. What comes after BA.5? Are new variants on the horizon?
No variant has outpaced BA.5 yet, but scientists monitor for troubling new mutants like BA.2.75 (“Centaurus”). The coronavirus will keep evolving, so we must stay vigilant.
5. How can we protect against BA.5 and future variants?
Get updated booster shots when available, especially the new bivalent boosters targeting Omicron. Additional layers of protection like masks, improved ventilation, and testing also help against circulating variants.
