Covid Variants: Will they keep on coming?
Last week, the director of the Center of Disease Control and Prevention (CDC) Dr. Rochelle Walensky warned that the United States is "not out of the woods yet", and that it is walking into “another pivotal point in this pandemic”. These statements are concurrent with the COVID Delta variant spreading through local and global communities. While most communities struggling with high infection rates of this variant are unvaccinated, the Delta variant still managed to pose a threat even to vaccinated communities. The Delta variant, a variant of recent concern, is a double mutant. In simple terms, this means that two different point mutations have been changed in the genome of the virus as compared to the original COVID virus that vaccines were designed to battle and protect against. It is suspected that the Delta variant is continuing to evolve and has emerged as a fast-growing virus outpacing other variants of concern that emerged prior to it. The Delta variant is the most common variant in India and has been spreading rapidly in countries like the United Kingdom, United States, and Israel; three countries that have some of the highest rates of vaccination around the world.
Can vaccines protect against variants?
With the emergence of variants, the protection rates against COVID-19 decreased drastically for both Pfizer and J&J vaccines, preliminary data has been showing. While the exact efficacy rates have not been finalized yet due to lack of data, it is estimated that the vaccines are 10-15% less protective against the Delta variants as opposed to the original virus. While the CDC and other public health authorities continuously warned of the possibility of breakthrough infections (e.g., infections among people who are fully vaccinated), the number of breakthrough infections has been increasing in the past days. If anything, what we are witnessing today is proving that there are more underlying issues that must be urgently addressed to end the COVID pandemic, including preventing further variants from evolving.
How do COVID variants emerge?
Populations in certain geographical contexts around the world continue to be unvaccinated completely, either due to unavailability of vaccines or vaccine hesitancy among the population. Among experts, this continues to raise a concern: unvaccinated areas are slowly becoming a breeding ground for emerging variants of the COVID virus. Rapid transmission of the virus among unvaccinated individuals can cause the virus to slightly modify its building blocks on the microcellular level. In turn, the “modified” virus, now referred to as a variant, can possibly travel and become a danger to even vaccinated and protected populations. This poses a huge danger to the mass vaccination campaigns that have been promising to mark the end of this pandemic. In a recent breakthrough in research, these assertions have been backed by research demonstrating that COVID-19 vaccines are fundamentally restricting the evolutionary and antigenic escape pathways accessible to SARS-CoV-2.
Variants are by-products of two major issues that the world faces in its battle with the pandemic. Firstly, vaccine inequality continues to be prevalent around the world. While some countries manage to have sufficient supply of vaccines for every citizen, other countries continue to struggle to secure any vaccines for their citizens. Such countries, largely unvaccinated, could foster an epidemiological environment that paves the way for variants to arise. This is particularly the case in areas with high populations and huge urbanized centers, where social distancing is more difficult to achieve. Second, vaccine hesitancy continues to create areas where many people are unvaccinated, regardless of accessibility. For instance, vaccination rates in Montana continue to lag behind other states, mainly due to a high reported rate of vaccine hesitancy . With a large proportion of the population being unvaccinated, the COVID virus has the potential to spread rapidly and infect many people. With continuous and rapid spreading, this creates an opportunity for the virus to slightly modify its genetic structure in a way that could allow it to become less susceptible to protection by vaccines. In turn, when arriving to areas where people are fully vaccinated, the virus could manage to infect and even lead to symptomatic disease among vaccinated people.
What is next?
Left unaddressed, the issue of insufficient vaccinations can create new variants that can break through the “immunity-shield” provided by the current vaccines, and severely complicate our battle with COVID.
It is yet unclear what the future holds for us with regards to community restrictions and measures to combat the COVID variants. However, backed with vaccinations and over a year of complex scientific developments relating to this virus, we may be more equipped than ever – we are in a very different position than what we were during last year’s global surge of cases. To successfully protect our communities from COVID and its variants today, there is a strong call to address both vaccine hesitancy and inequality. Concurrent to increased vaccination efforts, data driven systems can be beneficial in monitoring the emergence of breakthrough infections and the behavior of new variants. In turn, this can allow the scientific community and policymakers to make informed decisions and recommendations to prevent such variants of severely affecting our communities in the meantime.
References
1. Do COVID-19 vaccines protect against the variants? - Mayo Clinic. (2021). Retrieved 23 July 2021, from https://www.mayoclinic.org/coronavirus-covid-19/covid-variant-vaccine
2. Vaccine Hesitancy for COVID-19: State, County, and Local Estimates. (2021). Retrieved 22 July 2021, from https://aspe.hhs.gov/reports/vaccine-hesitancy-covid-19-state-county-local-estimates
3. Coronavirus Variants and Mutations. (2021). Retrieved 22 July 2021, from https://www.nytimes.com/interactive/2021/health/coronavirus-variant-tracker.html
4. Niesen, Michiel, et al. "COVID-19 vaccines dampen genomic diversity of SARS-CoV-2: Unvaccinated patients exhibit more antigenic mutational variance." medRxiv (2021).