Daily new coronavirus cases in San Diego County increased by a shocking 1321 percent from June 9, 2021 (71 cases) to August 9, 2021 (1009 cases). This jump is due to a perfect storm of the unvaccinated meeting the high transmission factor and massive viral load produced by the Delta variant, abetted by breakthrough and asymptomatic cases. Contrary to expectations San Diegans had for a ‘normal’ fall, we’re again facing renewed mask rules, limited indoor capacity, and uncertainty about crowds. Let’s address four of the most pressing questions about the Delta variant whose answers are critical to the health of seniors and caregivers in San Diego.
The Covid-19 virus is surging again nationally, thanks to the highly infectious Delta variant and low rates of vaccination in half of the states. San Diego reported 2,948 new cases on August 8th, the highest number of new daily cases since January 8, 2021. The CDC reports that this Covid variant causes twice as many infections as the original Covid virus, falling somewhere between HIV SARS and chickenpox on the contagiousness scale (called R-naught or R0.) The CDC just announced that even the vaccinated should now wear masks indoors, trailing some cities and states, including Nevada and Los Angeles, that had already re-instituted mask mandates earlier this summer.
Why does Delta spread so fast? The Delta variant’s specific mutations give it the advantage over the original COVID-19 strain that shut the world down in early 2020: a higher R0 number and a higher viral load. Chickenpox, an example the CDC recently used, has an R0 of 9-10, meaning each person with chickenpox infects 9 to 10 other people with chickenpox. The original (Wuhan) strain of Covid-19 had an R0 between two and three. Currently, the R0 for Delta is between six and seven. This means every person who contracts the Delta variant will infect between six and seven other people. One reason, per KQED.org, is that “one recent preprint study from China found that people who are infected with delta have — on average — about 1,000 times more copies of the virus in their respiratory tracts than those infected with the original strain and are infectious earlier in the course of their illness.”
What can stop Delta from spreading? NPR reported this week that “with an R0 of six, delta will be extremely difficult to slow down unless populations reach high levels of vaccination, [evolutionary biologist and biostatistician Tom] Wenseleers [at the University of Leuven in Belgium] says. And even then, surges in cases will still occur, as is now happening in Iceland and parts of the U.S. The vaccine is less than 90% effective at stopping infections with delta, meaning at least 1 in 10 people could have breakthrough infections. And vaccinated people can still spread the virus. In addition, people who aren’t vaccinated have a very high risk of infection, Wenseleers says. ‘Anyone that chooses not to get vaccinated will in all likelihood get infected by the delta variant over the coming months.’”
Who should now be wearing masks, and where? According to CNBC, “The Centers for Disease Control and Prevention recommended Tuesday that fully vaccinated people begin wearing masks indoors again in places with high Covid-19 transmission rates. (The advice for unvaccinated people to wear masks never changed.) The agency is also recommending kids wear masks in schools this fall.” High transmission rate areas are states or counties with more than 50 new infections per 100,000 residents in the prior seven days, or with a higher than eight percent positivity rate on all Covid tests. All residents of Florida, Arkansas and Louisiana, or residents of nearly two-thirds of all U.S. counties, live in a high transmission rate area.
If I had Covid already, do I need to get vaccinated now? The WUSA9 website confirms that “Even people who have recovered from COVID-19 are urged to get vaccinated, especially as the extra-contagious delta variant surges — and a new study shows survivors who ignored that advice were more than twice as likely to get reinfected…. According to a new Gallup survey, one of the main reasons Americans cite for not planning to get vaccinated is the belief that they’re protected since they already had COVID-19…. Scientists say infection does generally leave survivors protected against a serious reinfection at least with a similar version of the virus, but blood tests have signaled that protection drops against worrisome variants.”
To make a vaccine appointment for yourself or a loved one, please consult the resources we list on our blog “How Do Seniors Make Vaccination Appointments in San Diego?”