This obituary is part of a series about people who died from the coronavirus pandemic. Read about others here.

For nearly four decades, William R. Harris dedicated his career to protecting his fellow citizens.

As an international lawyer and sought-after advisor, he drafted contracts to prevent the proliferation of nuclear weapons and reduce the risk of accidental war. He modeled a framework for government to continue functioning during a national disaster. He helped extend daylight savings time to save fuel and kept officers focused on protecting the power grid from digital sabotage.

He also practiced what he preached and made sure he got his first vaccination against the coronavirus in early February as soon as he was eligible and the vaccine was available. He ended the regime by the end of the month.

However, in late March, his family received a harrowing diagnosis: Covid-19. Mr Harris also had chronic lymphocytic leukemia, and family members said that several weeks after learning he had Covid, he read an article in a scientific journal that suggested that the vaccine might be for people with this type of leukemia is not fully effective.

A week later, on April 21, he died in a hospital in Burlington, Massachusetts. He was 79 years old. His wife Elizabeth said the cause was Covid.

Leukemia and other diseases, as well as some treatments, can affect the immune system and prevent it from responding properly to vaccines, leaving people at risk of infection.

“They’ll be walking around outside thinking they’re protected – but maybe not,” said Dr. Lee Greenberger, scientific director of the Leukemia Lymphoma Society, told the New York Times last month.

No vaccine is 100 percent effective, and even healthy people who have been fully vaccinated can expect some breakthrough infections. But these cases are rare. On April 26, the Centers for Disease Control and Prevention reported 9,245 breakthrough cases from 95 million fully vaccinated Americans. 132 people died.

In a laudatory speech on Facebook, Harris’ daughter Darcy R. Harris described him as follows: “As an international attorney and wonk, his work included arms control treaties and verifications, energy policy and space law. He was an accomplished researcher, an early adopter, an innovator. He’s also always worked for free and helped others. “

Mr. Harris also left a legacy of community service. As a parent, he was committed to the integration of schools. He trained soccer. In Newburyport, Massachusetts, where he and his wife had lived since 2003, he worked to preserve the historic waterfront and make it accessible to the public.

Updated

May 13, 2021, 7:20 p.m. ET

From 1972 to 1991, he spent half of his career as an analyst with RAND Corporation in Santa Monica, California. He has also served as an advisor to agencies such as the National Security Council and the US Arms Control and Disarmament Agency, as well as to Congress committees.

During the Arab oil embargo, he called for both summer time, temporarily imposed in 1974, and a speed limit of 55 miles per hour to save gasoline. To encourage the use of solar energy, he supported laws passed in some states to protect a property owner’s access to sunlight.

He was concerned with improving the communications link between the White House and the Kremlin and setting legal limits on the use of space. He was also the vice chairman of the InfraGard National Disaster Resilience Council, a collaboration between the FBI and the private sector to protect vital services.

William Robert Horwitz (he changed his last name as a teenager) was born in Manhattan on July 30, 1941, the son of Dr. William A. Horwitz and Dr. Henriette Klein, who were both professors of clinical psychiatry at Columbia University.

He attended Dalton School in Manhattan and after graduating from Choate School, now Choate Rosemary Hall in Wallingford, Connecticut, earned a bachelor’s degree in history from Harvard College in 1962 and a law degree from Harvard Law School in 1966.

In 1968 he married Elizabeth Jones. Together with his wife and their daughter Darcy, he is survived by another daughter, Rebecca Harris Deane; one son, William Proctor Harris; four grandchildren; and his sister Susan Harris Molnar.