The Rockefeller University
 Office of the President | April 23, 2021

Dear colleagues,

We are enjoying another run of spectacular springtime weather, albeit on the chilly side, the campus landscape is nearing its peak, and we are finally seeing a very substantial drop in new COVID infections in New York City. All in all, a positive week!

After being steady at ~45 new COVID-19 cases per 100,000 people per day since early March, the infection rate in NYC has dropped very significantly in the last two weeks to 30 cases per 100,000 this morning (these values are the average of the prior seven days). The percentage of positive tests has dropped in parallel from ~4.0% to 2.7%, and there has been a similar drop in new hospitalizations for COVID-19. These abrupt improvements have been seen in all five boroughs of the city. Altogether, while the current levels of infection are still quite high, this sharp decline is great news. It is hard to know to what extent this is due to improving weather with people spending more time outside, or the effect of hitting critical levels of vaccination which, in combination with a significant level of prior infection in NYC, is increasingly limiting chains of viral transmission, or, as seems likely, a combination of both.

Across the rest of the country, overall infection rates are slightly down, but case levels are highly heterogeneous – extremely high across Michigan (62 cases per 100,000 per day), 10-fold lower across California (6 cases per 100,000 per day after being extremely high in Los Angeles in the winter), with worrisome increases in Oregon, Washington, North Carolina, and Maine.

Globally, the number of new cases per day is at an all-time high of 780,000, with high rates in many countries in South America, Europe, and the Middle East, and India is experiencing over 300,000 new cases per day, while most of Asia, Africa, and Oceania report very low levels.

On campus, the last two weeks have shown a significant reduction in new infections as well, dropping from 14 cases in the prior two weeks as reported in my last letter to only five new cases over the last two weeks now, among 2,931 tests performed by the Darnell laboratory.

Meanwhile, the national vaccination rollout continues. More than 125 million people in the US have received at least one dose of vaccine, with a daily average of ~3 million doses administered each day. Twenty-seven percent of the population has been fully vaccinated, and 41 percent have received at least one dose. The vaccines have been remarkably safe and extremely effective. Recent data from the US and around the world has documented the safety and efficacy of the approved vaccines. The CDC has shown in a real-world study using the Pfizer or Moderna vaccine that vaccination reduces all infections, including asymptomatic infections, by 90%, indicating that vaccination not only protects the vaccinated person from symptomatic infection, but also markedly reduces the likelihood of spreading the virus without symptoms. At Rockefeller, 77% of our 1,780-strong employees and students have had at least one dose of vaccine and 52% are fully vaccinated. Contract workers at Rockefeller are also getting vaccinated, with the Great Performances staff reaching 100% vaccination! And the overall vaccination numbers continue to climb. There is now ample supply of vaccine available, including sites with appointments available in all five boroughs. And for those of you coming to campus or in proximity, we have appointments dedicated to Rockefeller employees and their household members on campus at the BioLink every week through our partnership with the Hospital for Special Surgery. Through the following links you can register yourself or your household member. Please remember to notify once you have received your first and second doses.

Vaccination is by far the best way to protect your health and that of your family and colleagues. If you have not yet done so, I exhort you to make your appointment and get vaccinated! And please encourage your friends and loved ones to do so as well, especially those who may be reluctant. The vaccines are safe and effective and provide strong protection against serious disease and hospitalization.

The high efficacy of the vaccines has led to updated travel guidance from the Centers for Disease Control, which the University is following. If you have been fully vaccinated – meaning at least two weeks past the final vaccine dose – you no longer need to quarantine after exposure to positive or symptomatic individuals as long as you remain asymptomatic; you no longer need to quarantine after domestic or international travel; and you no longer need to complete the university travel form before traveling. Other policies remain unchanged, including for vaccinated individuals. Importantly, vaccinated individuals coming to campus must continue to participate in the RU Strong weekly testing program and must report to OHS any contact with a known positive or symptomatic case. Non-essential travel continues to be discouraged, and we expect to maintain our current phase III+ level of operation into the summer. For further information on current policies, visit the university’s COVID updates page.

Rockefeller research has continued at the highest levels throughout the pandemic. The lab of Luciano Marraffini, the Kayden Family Professor and head of the Laboratory of Bacteriology and an HHMI investigator, has recently published a fascinating paper in Nature reporting that the Staphylococcal type III-A CRISPR-Cas system has a previously unrecognized feature that can play an evolutionary role. In addition to destroying targeted RNA sequences, this Cas enzyme also has a non-specific single stranded DNAase activity. The lab speculated that this might induce cleavage in the host genome at sites of transcription or replication where single stranded DNA is exposed, with repair of these lesions producing mutations in the host genome. They found this to be the case, with an increased rate of development of antibiotic resistance owing to this increased mutation rate. This identifies a source of accelerated mutation rate that may be relevant to the evolution of these bacteria.

It has been a busy week for Luciano. This week, he was elected to membership in the American Academy of Arts and Sciences, founded in 1780 by John Adams, John Hancock, and founders of the country to bring together expertise in diverse disciplines to advance the nation. Luciano is recognized for his studies of the molecular mechanisms of CRISPR-Cas systems and their application in gene editing. Luciano will join 24 current Rockefeller scientists who are members of this organization. Congratulations, Luciano!

This week I’m also pleased to highlight a study led by Bob Darnell in conjunction with many Rockefeller colleagues that was published this week in the New England Journal of Medicine. The study reports on two cases of “breakthrough” COVID infection with variant viruses among fully vaccinated individuals at Rockefeller, both detected by the RU Strong testing program. Sequencing of the viral genomes revealed multiple mutations believed to increase infectiousness of the virus and/or cause resistance to antibodies produced by vaccination; one person’s virus had the E484K variant, which is prevalent in viruses in South Africa and Brazil, while the other virus had S477N, which has been spreading in New York since November. Antibody levels at the time of diagnosis in the former person were measured and were sky high, at levels only seen after completed vaccination, and indicated that the infection did not occur because of lack of response to vaccine. Interestingly, this person was in close contact with other family members prior to diagnosis and none became infected. Happily, both individuals only had mild symptoms and recovered uneventfully. We have subsequently had two more employees who have been partially vaccinated become infected. The results underscore that while vaccination is highly protective, we remain at risk, particularly from variant viruses, and must continue to take precautions to prevent infection and spread of virus and to be tested weekly to protect our families and one another.

As we near the end of the academic year and begin to make preparations for our second virtual Convocation, I am pleased to announce that we have recruited an exceptionally strong – and diverse – class of students to begin this fall. There were 982 applicants to The David Rockefeller Graduate Program this year, of which we interviewed 131 and accepted 78. Although our traditional open houses were conducted by video conference this year, we nonetheless saw a terrific yield: 32 of these applicants accepted offers to enroll, well above the 25 we projected. That’s an overall yield of 41 percent, the best in 20 years.

This year’s class comprises 18 women and 14 men; 16 U.S. citizens or residents and 16 international students; 10 students come from underrepresented backgrounds or disadvantaged communities. Congratulations to Sid Strickland and Emily Harms and their colleagues in the Dean’s Office for their outstanding work during this difficult recruiting period, to the HOL members of the student recruitment committee, and to the many current students who helped extol the merits of our world-class institution.

Speaking of academics, there’s good news this week from the Tri-Institutional community: After an extensive search, Katharine Hsu, an esteemed physician-scientist who specializes in immunology research and treatment of blood cancers, has been named director of the Tri-Institutional M.D.-Ph.D. Program. Hsu, who is a member of the Memorial Sloan Kettering faculty and is herself a graduate of this program, well understands the crucial role that graduates of this dual-degree program will play in the next generation of biomedical research. Coupled with the respect she commands in the Tri-Institutional community and her strong commitment to increasing diversity in both medicine and science, she will be a great leader for the program. She takes over for Olaf Andersen, who stepped down last year, leaving an indelible legacy of excellence.

Please stay safe, be well, and continue to take care of one another.


Richard P. Lifton, M.D., Ph.D.
Carson Family Professor
Laboratory of Human Genetics and Genomics
The Rockefeller University