The Delta COVID-19 variant has been around for some time now, with the first reported case tracing back to India in October of last year. But having been recently labeled a “variant of concern” by the World Health Organization (WHO), here are some facts you should know.
Are vaccinated individuals still safe?
The short answer is: yes. Dr. Jason Pogue, clinical professor at the University of Michigan College of Pharmacy, and colleagues recently conducted research about COVID-19 variants and mutations. Their findings are published in Oxford Academic.
In an email to The Michigan Daily, Pogue wrote that despite the skepticism and sparse research contradicting the vaccine’s efficacy against mutations, they do work against variants of concern (VOC). He wrote that doubts stem from data showing decreased function of neutralization antibodies, the antibodies that fight against the replication of COVID-19, for various VOC in vaccinated and previously infected patient serums, or blood samples.
“However, what is important to remember is that the neutralization by vaccinated patients is still actually quite impressive against these VOC, even if not quite as high as it is against the wild type (or original) virus,” Pogue wrote.
Pogue wrote that the immune response against a virus consists of much more than just the neutralizing antibodies. There are several aspects to the immune response against a virus such as T-cells and non-neutralizing antibodies, which still remain in high levels when measured against VOC, according to Pogue.
For reference, T-cells play a vital role in the protection against severe disease and non-neutralizing, or ‘binding’, antibodies work against viral particles they come across without halting replication.
Recent studies conclude that the Pfizer BioNTech vaccine is 88% effective against contracting the Delta variant and 96% effective against hospitalization compared to 95% and 100% against contraction and hospitalization of the original strain, respectively. The same study concluded that the Oxford-AstraZeneca vaccine is 60% effective against the contraction of the variant and 93% effective against hospitalization.
The study did not include the Moderna vaccine, but the company released a statement that their vaccine is still highly effective against the variant. More research is still needed to draw conclusions from the Johnson & Johnson and Novavax vaccines in regards to the Delta variant specifically.
Although research suggests vaccinated individuals are still safe from the variant, the WHO stated on June 25 that those who are vaccinated should take extra precaution and continue to wear masks to counteract the spread of the variant.
Dr. Soumya Swaminathan, WHO’s chief scientist, spoke on the matter during a conference at the company’s Geneva, Switzerland headquarters. She said the recommendation is because of the “significantly increased transmissibility” of the variant. The WHO’s recommendation contradicts the Centers for Disease Control and Prevention’s (CDC), causing government officials in several states to require or recommend masking again. For example, Los Angeles County released a statement last week strongly recommending their residents to wear masks indoors.
What makes the variant different?
The Delta variant, or SARS-CoV-2 B.1.617, has three subtypes: B.1.617.1, B.1.617.2 and B.1.617.3. The second of which, named ‘Delta plus,’ is the VOC while the first and third are currently labeled ‘variants of interest’. According to the Ministry of Information and Broadcasting of India, these variants can have 15 to 17 mutations.
Studies now suggest that the Delta variant is roughly 60% more transmissible than the current dominant variant in the United States – B.1.1.7, or ‘the Alpha variant’ – making it over 75% more transmissible than the original strand that appeared in Wuhan, China.
As well as being able to spread quickly, the variant is known to cause a more severe illness and a higher rate of hospitalization. According to the WHO, those who are fully vaccinated can still contract the variant, and all other forms of COVID-19 for that matter. No vaccine is 100% effective, but they all drastically reduce the severity of the illness and the chances of being hospitalized from COVID-19.
The variant is characterized by several mutations in the DNA that codes for the spike protein, or the projections on the SARS-CoV-2 virus that enable it to enter the body’s cells. According to Pogue, these mutations are not located in the region that would decrease the efficacy of the current vaccines.
How big is the variant’s impact in the United States and abroad?
Having already spread to over 92 countries, the variant has caused great distress around the world. Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), said the Delta variant is the “greatest threat” in the world’s efforts to contain COVID-19 during a White House briefing on June 22.
The variant has been causing surges in Russia, Indonesia, India and many other countries including the United States. In the U.S., COVID-19 cases have risen 10% in the last week. The variant now accounts for roughly 80% of new cases in states like Kansas and Arkansas, and over 96% of new cases in Missouri.
These statistics are not surprising to Dr. Joseph Eisenberg, professor and chair of the U-M department of epidemiology, who believes that the country will be seeing clusters of cases in Southern states where the vaccination percentage, or ‘coverage,’ is low.
“I think that the outbreaks, moving forward, will be more focused geographically, and won’t spread in the same way as it has in the pandemic because we have a fair amount of coverage,” Eisenberg said. “Where we see low coverage, like in the South, we’re likely to see more outbreaks and potentially even more spread within the state. In states where there’s much better coverage, we might be more likely to see very localized case clusters that die out in the same geographical location that they started.”
Both Eisenberg and Pogue stressed the importance of being vaccinated. Eisenberg said the struggle against COVID-19 will continue so long as vaccines are limited in various undersupplied countries.
“Globally, we need to get the vaccine to these countries that don’t have access to vaccines and we really need to mobilize and work on developing an infrastructure where the vaccine implementation can be more efficient and more accessible to the population,” Eisenberg said. “I think that as long as there are countries that don’t have access to the vaccine, it will remain a global problem.”
Eisenberg also said that once children under the age of 12 are eligible to get vaccinated, that should become a major priority globally and within the United States. In late May, the CDC announced that the vaccines are safe for children ages 12 to 15, and studies are currently underway for the next younger age group.
The CDC states that while children are less likely to get COVID-19, those under 12 are still susceptible to COVID-19 contraction. For now, the CDC recommends that those who are traveling with unvaccinated children take extra precautions like masking indoors and avoiding crowded areas.
Daily Staff Reporter Nadir Al-Saidi can be reached at alsaidin@umich.edu.