A brief post on vaccines designed to fight the current pandemic… Vaccines have been used for more than two centuries to protect people from disease. All vaccines are designed to work in more or less the same way; to trigger an immune response in the host that is directed specifically against some microbial invader. This response primes the immune system and allows for a more rapid, sustained, and efficacious reaction. In the past, most vaccines used killed or weakened microbes as the agent to set off immunity. Usually, proteins on the surface of these pathogens are recognized as foreign subst ..read more

I'm afraid. Not about the present political situation (although that's pretty scary too). I'm frightened because of a graph that is updated daily on this site from the Covid Tracking Project. It's a plot of the daily deaths from the SARS-CoV-2 virus versus the number of new infections, On the right I show the latest version that was posted on November 21. The seven day average of daily Covid19 cases is shown in red. The black line represents the number of deaths similarly averaged over a seven day period. I've labeled the graph with three numbers representing the three phases of the pandemic ..read more

It's been two months since my last confession --- posting. Since that time the number of deaths in the United States from the virus has risen from about 18,000 to about 110,000. But the two month period hasn't changed the debate: Should we open up more? Should we stop the measures that we've taken and go back to pre-Covid days? Or should we continue to shut down? For reasons that I don't really comprehend, the disagreement has degenerated (as many these days do) into something political - into a largely left/right issue. One side points to the effects on the economy. The statistics are indeed ..read more

It’s instructive to see how countries around the globe are handling the current pandemic – and to compare how we're doing in the United States to how other nations are coping with the scourge. Wikipedia (one of the great resources of the digital age) has offered up a slew of comprehensive reports on how the virus has affected many nations and how each has responded. I’ve taken advantage of them in writing this posting. They can be accessed on Wikipedia by entering “Coronavirus in [name of country]” in your search engine. The disease originated in China, with the first case reported in the m ..read more

Coronaviruses   In light of the current outbreak, I thought that I would share some of what I’ve learned about the molecular biology of the coronarviruses in general and the Covid-19 virus in particular. My goal will be to describe how the virus acts in terms mostly devoid of the technical jargon that makes molecular biology so difficult for most people to understand. First of all, what’s a virus? Some people have suggested that viruses aren’t alive. Of course, that isn’t the case. Viruses don’t move about like tigers or grow like poison ivy, but they are organisms that can reproduce, unde ..read more

This is a file from the Wikimedia Commons File:Working principle of telomerase.png The subject of my last posting was the epigenetic clock. This one is about another biological mechanism for keeping time. Way back in November 2018, I posted a short note (#43) entitled “Cancer Cell Immortality” in which I discussed the subject of chromosome ends and their relation to cancer and aging. Here’s a short summary. Many decades ago the eminent biologist Leonard Hayflick discovered that most cells when placed into tissue culture have a limited life span, now known as the Hayflick Limit. It was subsequ ..read more

Epigenetics and Aging New acquaintances would often ask what I did for a living before I retired. I would have to confess that in my former life I was a Professor of Genetics. What would follow would be a prolonged and uncomfortable pause in the conversation. “That’s a fascinating field”, would come the response after the delay. Surprisingly, a frequent question that might follow would be, “What’s all this I hear about epigenetics?” Apparently epigenetics is becoming a subject of public discourse. I’m never sure what to answer. It’s not a subject I’ve studied over the years, but a recent p ..read more

Mom in Brooklyn, circa 1940 Henny My mother – formally named “Henrietta, but universally called “Henny – was a beautiful, energetic, and loving woman. Brought up in the Bronx, she and her three sisters suffered the loss of their father while teenagers. Her oldest sister, Belle, managed to earn a college degree, but my grandfather’s death meant that mom had to drop our of high school to help contribute to the family’s finances.Without a high school diploma it was difficult to find a good job, particularly during the depression, but by assuming Belle’s identity, she was able to secure a well pa ..read more

Dad at about age 35. I hold a grudge against Dr. Alzheimer and his eponymous disease. Well, perhaps not against the good doctor who was the first to characterize what he called “presenile dementia” in a 51 year old patient at the beginning of the twentieth century. But certainly against the disease that ultimately stole the minds of both of my parents. Their suffering still haunts me. My father first showed evidence of dementia in his late 60’s. At a party on the occasion of my oldest son's bar mitzvah, a neighbor, a nurse, approached me. She had been engaged in a long conversation with my da ..read more