September 07, 2021
1 min read
Farraye F. COVID-19 Delta update. Presented at: ACG Virtual Grand Rounds 2021; August 31 (virtual meeting).
Farraye reports receiving consulting fees from Arena, , Braintree Labs, Gilead, GI Reviewers, , IBD Educational Group, Iterative Scopes, Janssen, Pfizer and Sebela as well as ownership interest in Innovation Pharmaceuticals.
In the wake of the COVID-19 delta variant, prevention strategies must be continued including vaccination, masking and distancing for all, according to a presenter at the ACG Virtual Grand Rounds 2021.
“The delta variant is the most common strain in the U.S. since late June 2021 with viral loads 1,000 to 1,200 times higher than the original strain,” Francis A. Farraye, MD, MSc, MACG, Mayo Clinic, said. “It is more than twofold more contagious than previous variants and as contagious as chicken pox.”
Farraye reported the basic reproductive number, or the average number of people every infected person will spread the virus to within a susceptible population, increased from an estimated two people to four people for the original COVID strain to six people with the delta variant. The unvaccinated population remains the greatest concern as evidence demonstrated delta caused more severe disease outcomes compared with vaccinated individuals who appeared to be infectious for shorter periods.
While urging the general population to get vaccinated remains a top priority, its effectiveness against the delta variant has been called into question. The CDC’s Morbidity and Mortality Weekly reported a study analyzing 4,000 health care workers (83% vaccinated) from December 2020 through August 2021 revealed a decline in vaccine effectiveness following the rise of the delta variant (91% vs. 66%). Researchers related the increased prevalence of waning immunity to the lapsed time from vaccination.
“Breakthrough infections are to be expected and mitigating activities of masking and distancing includes vaccinated individuals,” Farraye concluded. “Recommendations will certainly and appropriately change as we learn more about SARS-CoV-2 variants.”