Yonatan Grad

@yhgrad.bsky.social

Prof @ Harvard Chan School of Public Health, Director, Center for Communicable Disease Dynamics. Antimicrobial resistance, STIs, N. gonorrhoeae, pandemic preparedness/response, pathogen genomics, mathematical modeling, ID epi

I'm excited to share a preprint that's been years in the making: the idea took shape during the COVID pandemic. Anecdotally, people would sometimes spread COVID at work but not at home, and vice versa. Why? One explanation would be if infectiousness is fleeting...

How bursty infectiousness shapes epidemic dynamics

An epidemic’s expected course is determined by the magnitude and timing of a typical person’s infectiousness — captured, in turn, by the basic reproduction number and the generation-time distribution....

medrxiv.org

Our GoGoVax trial is now published. We found no evidence that 4CMenB prevents gonorrhoea in gay and bisexual men at high risk of infection, providing important evidence to guide gonorrhoea prevention efforts. Thanks to all participants, clinics, & collaborators involved. www.nejm.org/doi/full/10....

Meningococcal B Vaccine to Prevent Neisseria gonorrhoeae Infection | NEJM

No vaccines are currently licensed for the prevention of Neisseria gonorrhoeae infection. Observational studies suggest that the four-component meningococcal serogroup B vaccine (4CMenB) may reduce...

nejm.org

🚨 Disease modelers: Do you use empirical VE estimates interchangeably to inform vaccine effect parameters? Me too, and it’s distorting our predictions. VE estimates often do not align with model parameters. We discuss these pitfalls & solutions in our new preprint: arxiv.org/abs/2605.18571 🧵👇

Incorporating vaccine effects into epidemiological models: common pitfalls and solutions

Incorporating vaccination into mathematical models appears deceptively simple: models integrate vaccine-derived protections, such as reduced susceptibility to infection, using parameters informed by e...

arxiv.org

“It was Barry who discovered that lymphocytes-not macrophages, as some hypothesized-that carry immune memory. showed that lymphocytes signal to macrophages through a chemical they termed MIF-which, together w/ interferon, were the 1st cytokines discovered” www.statnews.com/2026/03/30/b...

Remembering public health pioneer Barry Bloom: a scientist, a mentor, a mensch

Marc Lipsitch and Yonatan Grad pay tribute to their former colleague and mentor Barry R. Bloom.

statnews.com

I'm thankful to MBE for publishing this paper. I wan't sure anybody would. The handling editor (I now know was Jeff Townsend) was great, as were the 2 reviewers. It is not an outcome/product/discovery, it is my way of thinking about HGT & pangenomes 1/3 academic.oup.com/mbe/article/...

Genomic perplexity and the evolution of context-dependent function

Abstract. The fundamental principle that selection acts on a gene's function often assumes implicitly that this function is fixed and intrinsic. However, e

academic.oup.com

I am seeking a postdoc to join my group at UCLA -- ideally the candidate would have some experience in either population genetics or microbes/microbiome (computational background needed). We have a range of projects and are happy to tailer to your interests. Please dm/email me if interested.

Models can be powerful tools to study associations in data. But do they reliably reveal the truth? 🚨 In our new study, @danlarremore.bsky.social and I show that the model used to estimate VE from test-negative designs (TNDs) may not translate to other correlates of risk. doi.org/10.1093/aje/...

Statistical methods for estimating the protective effects of immune markers using test-negative designs

Abstract. While widely used to study vaccine effectiveness, test-negative designs (TNDs) also provide a platform for identifying and quantifying immunologi

doi.org