Unvaccinated areas across the country are beginning to see a sharp rise in new Covid-19 cases as the Delta variant takes hold. In the US, the Delta variant now accounts for 83% of cases, a 33% increase from two weeks ago, according to Centers for Disease Control and Prevention (CDC) Director Rochelle Walensky.
The CDC has officially classified the Delta variant as a variant of concern, meaning there is clear evidence indicating a significant impact on transmissibility. Recent studies have shown the Delta variant to be about 50% more transmissible than the original SARS-CoV-2 strain, and those who have been infected have 1,000 times more copies of the virus in their respiratory tracts, making it the most contagious variant to date.
Thompson W. Liddell, MD, an infectious disease expert at Hattiesburg Clinic, explained how these different versions, or variants, of Covid-19 emerge and what leads scientists to ultimately classify the variant as a “variant of concern.”
“Every time a virus replicates, mistakes occur in its genetic code,” Dr. Liddell said. “The majority of those mistakes lead to the virus not living or don’t make much of an impact to the virus; however, every now and then, these changes give the virus an advantage, and that’s what we see with the variants of concern. The characteristics of these variants of concern include increased transmissibility, increased disease severity and evidence of the impact on diagnostics, treatment and vaccines.”
The SARS-CoV-2 variant classification table is divided into three parts: variants of interest, variants of concern and variants of high consequence. Fortunately, we have not seen variants of high consequence, which means the variant is untreatable or particularly deadly.
“We only have so much time to stop variants from developing, and the best tool we have to do that is through vaccination,” Dr. Liddell said. “By vaccinating, we decrease the number of cases. By decreasing the number of cases, we decrease the number of replications. By decreasing the number of replications, we decrease the number of mutations. And by decreasing the number of mutations, we decrease the number of variants.
“The way to win and to defeat the virus is to get ahead of it by vaccination,” he added. “If we’re not able to get ahead of it, or if we allow variants like the Delta variant to slide past us due to low vaccination rates, it’s going to lead to other variants. The Delta variant won’t be the last one we see.”
On Thursday, Covid-19 infections in Mississippi reached 1,908 cases, which the state hasn’t seen since February. In the last week at Hattiesburg Clinic alone, 469 patients were diagnosed with Covid-19 with over 85% of the positive cases occurring in unvaccinated patients. As cases continue to climb, it becomes increasingly important to improve vaccination rates.
The development and distribution of the current vaccines was an extraordinary medical achievement. The rapid response by the US government and its efforts to fund the vaccines allowed the production of not just one, but three highly effective vaccines in the fight against Covid-19.
“Now, we’re facing this Delta variant, which is only a sign of things to come,” Dr. Liddell said. “Covid-19 is changing, and it’s going to continue to change unless we see higher vaccination rates.”
The current vaccines are highly effective in preventing the virus. While no vaccine is 100% effective against a disease, the mRNA vaccines have shown to be up to 96% effective against the original coronavirus strain, up to 94% against the Alpha variant and 88% effective against the Delta variant. However, the more variants that emerge, the more likely the virus is to change and potentially lessen the efficacy of the vaccines.