Covid19mathblog.com

Interesting points from this article discussing whether vaccine would stop transmission – https://www.popsci.com/story/health/covid-19-vaccine-effective-prevent-spread-infection/

“One reason that this novel virus—officially called SARS-CoV-2—has spread so rampantly is that people can be contagious several days before they feel ill, and in some cases never develop symptoms. Such a high rate of asymptomatic spread is “just not all that common in other infections,” says Susanna Naggie, an associate professor of medicine in the Duke University School of Medicine who specializes in infectious diseases. “With flu there is asymptomatic disease, but not at the level we see with SARS-CoV-2.” This makes it particularly important to understand whether COVID-19 vaccines will prevent asymptomatic infections, she says.”

“Many vaccines—including those for hepatitis A and B, measles, chickenpox, and human papillomavirus—do prevent people both from becoming ill and from passing the pathogen to others. “Generally, we believe that if you have a vaccine that prevents disease, you’re likely preventing infections as well, but you can’t assume that that’s 100 percent [the case],” Naggie says.

Some pathogens can infect and reproduce in vaccinated people for short periods of time without making them sick, including the bacteria that cause meningitis and pertussis, or whooping cough. This is also a problem for vaccines under development for parasitic illnesses such as malaria, schistosomiasis, and hookworm infection, Bethony says. “The vaccine protects people against the most serious clinical manifestations of the disease but it doesn’t entirely stop infection,” Bethony says. “You still might have a person who is mildly infected, and they’re still able to spread the disease.””

“Several developers have reported early data hinting that their COVID-19 vaccines will reduce asymptomatic infections. During late-stage trials for the vaccine developed by the University of Oxford and AstraZeneca, some participants were given weekly COVID-19 tests. One group accidentally was given a low first dose of the vaccine followed by the intended full second dose. Asymptomatic infections were less common in this vaccinated group than they were among those who received a placebo. Researchers are still investigating why that low-dose group fared better than the full-dose group in that regard.

In Moderna’s clinical trials, researchers swabbed participants before they received each of their two doses of the vaccine. On December 15, the drugmaker reported that 38 volunteers who received the placebo tested positive without showing COVID-19 symptoms before their second dose, compared with only 14 from the group that received the vaccine.

“Presumably that means it also decreases the risk of transmission, although to prove that will take a lot more work,” Naggie says. “Maybe the vaccine completely prevents infection, or maybe it really shortens the period of infection and someone sheds for only a couple of days…these would all be very critical pieces to answer that.””

Only 1209 deaths in the US reported – but alas its Sunday

US and East Europe for the last 30 days is where most of the confirmation per capita is occuring (>1%)

CA leads in confirmation again – NY leads in death at 125

On a county view NY doesn’t even show up. LA continues to be a concern.

Death in NY very disperse

LA perhaps could be flatlining but hard to tell with the holiday reporting – even yet still a long ways down.