The Omicron BA.5 Variant and the Coronavirus Pandemic

An analysis of the latest Omicron COVID-19 variant, BA.5.


Fusion Medical Animation / Unsplash

The new subvariant, BA.5, has shown an increased ability to mutate and change its protein structure.

In New York City, with one of the highest vaccination rates in America, almost 90% of New Yorkers have received at least one dose of a Coronavirus vaccine, and over three-fourths are fully vaccinated. However, wave after wave of new highly transmissible variants have kept the infection rates across America and around the world, at a high level. 

Throughout America and the world, BA.5 has become the new dominant strand of Omicron, replacing the original BA.2 that caused the sweeping case surge seen in January 2022. What sets BA.5 apart from BA.2 is its even greater ability to evade the immune system, enabled by further mutations that render antibodies from vaccinations and previous infections less effective. So, if you’re one of the many who contracted Omicron in January, immunity to reinfection is no longer a guarantee.

But how much ability do we have to lower the number of infections with this new wave of the Omicron BA.5 variant, just a few months after the last? For the past few months, NYC health officials have been recommending masking while cases climb, but hesitate to re-mandate. While over 50% of Americans said they favored required masking on public transportation in a recent poll, the reality is less assuring. Mask compliancy rates in the MTA are at an all time low since the start of the pandemic, when maskless rates were at an all-time high, raising the question of whether a mandate would be followed this far into the pandemic remains to be seen.  

This contrast is nothing new, however — in August of 2021, cases suddenly rose and plateaued in a gradual wave that would give way to the January 2022 surge. As cases continuously hit new highs, MTA compliancy rates began to slump. Requests that riders exit the train for not wearing a mask by the police dropped by 96%, and a total of zero fines or summons were handed out to people who refused to comply. 

But where New York City shows hesitancy to re-mandate masking, other cities display indecisiveness. In late April 2022, the Philadelphia Board of Health voted to rescind a mask mandate instituted just four days prior, citing a plateau in case counts. Over a month later, the daily case count has risen by almost 25%, with the largest swell of the surge felt in mid-May 2022. 

NYC has followed much the same. Nearly a month after indoor masking was no longer required, case counts rose once more. In just over two weeks, NYC moved from a low COVID alert to a high alert as cases surpassed an average rate of 345 per 100,000 people in the five boroughs. More recently, it lowered back to medium, as the surge appears to be abating. 

Regardless of the diversity of opinions on masking, being vaccinated and up-to-date on booster shots is imperative to staying safe at this stage of the pandemic. While vaccines do not guarantee being COVID-free, they will contribute to a milder case, and a lesser likelihood of a hospital stay. Unvaccinated people are eight times more likely to die from COVID-19 than vaccinated people, even if they’ve only received one dose. Positive test rates for unvaccinated people skyrocketed in early May, towering over the statistics of any other demographic at over 1,400 cases per 100,000 people and rising. It’s a far cry from the stable number of vaccinated and boosted cases sitting at just over 320. 

But those numbers could be subject to change — and soon. A study published in late February of this year assessing the duration of protection offered by vaccines found that 20-30% of their efficacy is lost after 6 months. When vaccines became available to the public in January 2021, millions of New Yorkers rushed to get vaccinated. Later, mid-April saw the highest number of vaccines administered in any day of the pandemic. 

Five months later, cases spiked from August to September. The vaccination spike that occurred in December 2021 could explain the recent May case surge. Based on existing vaccination and case trends, a COVID surge every five months seems to be the current trajectory for the pandemic. 

But in the aftermath, instead of taking precautions to help lessen the impact of future surges, New York appears to be taking contrary measures. Unvaccinated state employees will no longer be weekly tested for COVID as of June 7th, 2022. In early March 2022, indoor school masking for grades K-12 was no longer required, but mandatory masking remained for preschoolers, as vaccines were not available to them. Now, their mask mandate has been lifted, marking the removal of the final public school mask mandate. 

Pfizer and Moderna have been granted emergency authorization of their vaccines for children aged 6 months to 6 years. A clinical trial published in late May by Pfizer on immune response and vaccine efficacy shows promise. The vaccine, when divided into 3 doses, was over 80% effective with the third dose cited as “well received.” In addition, on May 19th, 2022, the CDC expanded eligibility for many people’s first and only booster shot to everyone of 5 years and older. We’ve yet to see the same inclusivity with the second booster, authorized in late March by the FDA, and currently only available for those aged 50 and above and the immunocompromised.

Meanwhile, Moderna’s new bivalent vaccine — meaning that it protects against two viral strains instead of only one — will protect against both the original COVID strain, as well as one targeting Omicron specifically. Side effects are no worse than the first booster, but antibody levels increase eight-fold, giving hope that future vaccines will offer more protection against Omicron and its numerous variants. “We anticipate more durable protection against variants of concern with mRNA-1273.214, making it our lead candidate for a Fall 2022 booster,” Moderna CEO Stéphane Bancel said. 

What sets BA.5 apart from BA.2 is its even greater ability to evade the immune system, enabled by further mutations that render antibodies from vaccinations and previous infections less effective. So, if you’re one of the many who contracted Omicron in January, immunity to reinfection is no longer a guarantee.