2023 New Year’s Letter from Prof. Marc Lipsitch, CCDD Director

  Dear colleagues, alumni and friends, New year’s greetings from the Center for Communicable Disease Dynamics (CCDD) at the Harvard Chan School. A lot has happened in the world of infectious diseases since I last wrote to you in Fall 2021, when I was beginning my temporary role as Director of Science for the Center for Forecasting and Outbreak Analytics (CFA) at CDC. More on that exciting work below. In…

New CDC Role and Fall 2021 Update

Dear colleagues, alumni and friends, As fall begins, I’m writing to share some exciting news and an update on our activities at the Center for Communicable Disease Dynamics (CCDD). While remaining the Director of CCDD, I have begun a new, yearlong role as Director of Science for the Center for Forecasting and Outbreak Analytics at CDC. This new center was called for in President Biden’s National Security Memo #1 and…

New Year’s Letter from Dr. Marc Lipsitch, CCDD Director

Dear colleagues, alumni, and friends, As we start the new year, it is a privilege to write to you with some reflections on 2020, a year like no other, and to offer some perspective on the year ahead. I lead the Center for Communicable Disease Dynamics at the Harvard Chan School. Our group consists of me, Drs. Caroline Buckee, Bill Hanage and Michael Mina, about 15 postdocs and 15 PhD…

COVID-19 Vaccines and Herd Immunity

By Marc Lipsitch How many people in a population will need to get a COVID-19 vaccine before herd immunity is achieved? This question has been all over the news lately, with speculations of 70%, 80%, or other numbers. The math needed to answer this question is simple, but the question is, in my opinion, unanswerable at this point because the inputs to the math — the numbers to plug into…

Declaration of Dr. Marc Lipsitch and Emma Accorsi regarding Oregon Temporary rule 437-001-0749

Oregon’s Occupational Health and Safety Administration (OR OSHA) regulates farmworkers’ working and housing conditions, including conditions in approximately 330 employer-owned labor housing sites in the state. With the spread of COVID-19, OR OSHA issued temporary COVID-19 standards for agriculture that went into effect on June 1, 2020.  Although the temporary standards included other COVID-19 precautions for labor housing, transportation, and field sanitation, they critically did not increase the required living…

Protecting the Public’s Health During Protests Against Systemic Racism

Protests are important—they are a key medium for illuminating injustices that have long been ignored. Today, protests are being used as critical platforms for advocating against the structures that allow police brutality to persist and to go unpunished. However, as infectious disease epidemiologists, we recognize that protests can multiply the opportunities for COVID-19 transmission. We also know that African Americans already experience significant health inequities, including more heart disease, maternal…