Revisiting Face Masks Amidst New Coronavirus Variants
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Understanding New Coronavirus Variants
The emergence of a new coronavirus variant, designated B.1.1.7, was first noted in the UK in October 2020, with initial samples taken from Kent and London. Coronaviruses, like other viral pathogens, frequently undergo mutations. However, unlike the influenza virus, the virus responsible for COVID-19 (SARS-CoV-2) mutates at a slower pace. When sufficient mutations occur to alter a portion of the virus's genetic makeup, a new variant can arise. This particular variant has been linked to a notable surge in case numbers in southeastern England, with researchers estimating it to be 50 to 70% more transmissible than earlier strains. Following this, additional highly contagious variants have also been identified in South Africa and Brazil.
U.K. Prime Minister Boris Johnson remarked during a press briefing that the variant first identified in London and the southeast could potentially lead to a higher mortality rate. While initial evidence, presented in a preliminary report, suggested a "realistic possibility" of increased lethality, it also pointed out that this data was derived from a limited subset of deaths—approximately 8% of the total in Britain. Further data collection and analysis will be necessary to ascertain the true impact of this variant. In the meantime, it is prudent to proceed with caution. For insights from Prime Minister Boris Johnson and a BBC report, refer to the following video.
Current research on mRNA vaccines from Pfizer and Moderna, as well as the Oxford/AstraZeneca vaccine, indicates their efficacy against the U.K. variant. However, uncertainties linger regarding their effectiveness against variants originating in South Africa and Brazil. Moderna has announced efforts to develop a COVID booster shot targeting the South African variant. Researchers in South Africa have observed that this variant may evade neutralizing antibodies, potentially increasing its severity in infected individuals. These findings carry significant implications for the effectiveness of ongoing vaccine developments and therapeutic strategies.
The U.K. variant has been reported in 23 cities across the U.S., although Ohio is not among them. Researchers at Ohio State University’s Wexner Medical Center have identified two new variants of the coronavirus. One, known as the “Columbus strain,” features three mutations never seen together before in SARS-CoV-2. The other mirrors mutations found in both the U.K. and South African strains. As of now, there have been no cases of the South African variant detected in the United States. Vigilance is crucial, as there is typically a lag of 1 to 2 months between the virus's spread in Europe and its appearance in the U.S. Consequently, President Biden has instituted a travel ban for non-U.S. residents arriving from South Africa, requiring all travelers to present a negative COVID test and undergo quarantine upon entering the U.S.
The United States has the highest number of coronavirus infections globally, yet it lags in genomic sequencing to monitor genetic changes. The share of SARS-CoV-2 genomes submitted by the U.S. to GISAID, a global science initiative, is less than 0.3% of the total COVID-19 cases. In contrast, the U.K. has submitted nearly 5%, Denmark approximately 12%, and Australia close to 60%.
The Evolution of Virus Mutations
Sarah Zhang, a writer for The Atlantic, highlights concerning trends regarding coronavirus variants in a recent article. While the specific roles of mutations remain unclear, one mutation in the spike protein, called N501Y, is particularly noteworthy as it is present in all three variants identified in the U.K., South Africa, and Brazil. The spike protein facilitates the entry of the virus into human cells, and the N501Y mutation occurs in a critical area known as the receptor-binding domain, which attaches to cells. This mutation may enhance the spike protein's ability to latch onto cells, thereby increasing the virus's transmissibility.
Zhang also explains the nomenclature of these mutations. Amino acids, the building blocks of proteins, are denoted by letters. In the case of N501Y, the 501st amino acid originally represented as N (asparagine) has changed to Y (tyrosine). For more detailed insights, watch the video from ITV News. The CDC has recently warned that this variant is likely to become the dominant strain in the U.S. by March.
Are Vaccines Still Effective?
In an interview with Vineet Menachery, Ph.D., a coronavirus researcher at the University of Texas Medical Branch, Zhang noted that a single mutation is unlikely to fully undermine immunity from previous infections or vaccines. According to Menachery, current vaccines provide a robust immune response, asserting, “even if you cut that amount in half, you still have more than enough antibody to control the virus.”
The Wall Street Journal has reported on the perspective of Anthony Harnden, a physician advising the U.K. government, stating, “We’re living in a world where coronavirus is so prevalent and rapidly mutating that new variants will continue to emerge. We may eventually need to consider annual coronavirus vaccinations to manage these strains.”
Reassessing Face Mask Usage
Given the current context, it is essential to reconsider the role of face coverings. Effective face masks are vital in curbing the spread of COVID-19. There are various types of masks available, and their usage in public has become increasingly common. This website offers detailed information on mask standards and their effectiveness.
The types of masks commonly used include:
Surgical Masks: These disposable masks are effective in filtering large airborne particles and help protect others by reducing the exposure to the wearer’s saliva and respiratory droplets.
Cloth Masks: Designed to trap droplets released when the wearer talks, coughs, or sneezes, their effectiveness varies depending on the fabric type and layering.
Cloth Masks with Filter Pockets: These are preferable as they allow for additional protection with filters, which can be hand-washed and reused several times.
N95/KN95 Masks: These respirators provide superior protection compared to surgical and cloth masks, filtering out both large and 95% of small particles during inhalation. N95 masks are generally disposable, although hospitals have sometimes disinfected and reused them due to shortages.
It’s important to note that disposable masks should be discarded by the end of the day at the latest, while cloth masks should be washed with warm water and soap after use.
As reported by the Boston Herald, several European nations are urging citizens to replace cloth face coverings with medical-grade masks. France now recommends surgical masks for public settings, while Germany and Austria mandate such masks on public transportation, in workplaces, and at retail locations.
Dr. Atul Gawande from Harvard Medical School recently emphasized the importance of medical-grade masks in curtailing the spread of the U.K. variant, noting that research indicates that single-layer cloth masks are less effective than surgical masks and that N95 or KN95 masks provide even better protection. President Biden has enacted an executive order requiring mask usage in federal properties.
Dr. Joseph G. Allen from Harvard’s School of Public Health advocates for the widespread use of N95 masks, asserting that the effectiveness of a mask hinges not only on its filtration capabilities but also on its fit. A mask should cover the bridge of the nose, extend around the chin, and fit snugly against the cheeks.
While standard cloth masks filter about 50% of particles, wearing two masks can increase this filtration rate to 75%. Variants of N95 masks are now available that fit closely to the face, covering both the nose and mouth. Personally, I have purchased such masks to wear in high-risk public spaces such as grocery stores. In close contact situations, I opt for a surgical mask or layer a cloth mask over it, and at times, I may choose to wear an N95 mask.
Until the nation achieves herd immunity by vaccinating 75% to 80% of the population, the best defenses against COVID-19 remain mask usage, hand hygiene, and social distancing.
