Efficacy of COVID-19 Vaccines in Real-World Settings Even Better Than Expected, Fauci Says

Anthony Fauci, MD, highlighted this weekend that the real-world evidence of vaccines against SARS-CoV-2, the virus that causes COVID-19, is even better than expected.

The head of the National Institute of Allergy and Infectious Diseases and chief medical advisor to President Joe Biden also reiterated the administration’s goal of having 70% of US adults inoculated with at least 1 dose of a COVID-19 vaccine by July 4.

During a prerecorded speech to kick off the ATS 2021 International Conference, Fauci recapped what researchers and clinicians have learned about the disease since it first appeared in China at the end of 2019 and early 2020, and the challenges that remain to defeat the virus.

He called it “the most devastating pandemic of a respiratory illness in the last 102 years.”

Estimates of illness and death—both globally and in the United States—are likely undercounted, he repeatedly emphasized. Worldwide, about 160 million have been infected and 3.3 million have died; US deaths are close to 580,000 and infections have surpassed 30 million.

The United States has yet to get its baseline count of infection down to a low level, as each of the 3 deadly surges over the past year left the country worse off than before. Currently, the number of daily infections has dropped to about 40,000 a day down from 60,000 a few weeks ago.

He contrasted that with Israel, which implemented a very robust vaccination program and now has few infections.

Referring to a recent editorial he wrote for the journal Science, Fauci pointed out that the scientific research that gave rise to the 3 approved vaccines in the United States began decades ago. The belief that somehow the vaccine technology is new or unproven is just one of many factors contributing to vaccine hesitancy in the United States.

Clinical US trials of the Pfizer/BioNTech and Moderna vaccines showed 95% and 94.1% efficacy, he said. The Johnson & Johnson vaccine, which was tested in the United States, Brazil, and South Africa, had 66% efficacy overall and 85% efficacy against severe disease.

"Now, usually, as many of you know, the effectiveness in the real world is often not as good as the efficacy in the pristine conditions of a clinical trial," Fauci said. "We have found just the opposite with COVID-19 vaccines, where effectiveness is easily as good, if not better, in the real world setting."

He cited a study of more than 23,000 employees of the University of Texas Southwestern Medical Center in Dallas, where vaccinations began December 15, 2020. There was just a 0.05% infection rate among workers who were fully immunized, he said.

Another study looked at the efficacy of vaccines in 8 US locations of close to 4000 essential and frontline health care workers. There were just 3 polymerase chain reaction (PCR)-confirmed infections during 78,902 person-days with full immunization (0.04/1000 person-days).

Fauci also referenced a study published in The Lancet earlier this month looking at the impact of the Pfizer/BioNTech vaccine on infections, hospitalizations, and deaths in Israel after a nationwide vaccination campaign began on December 20, 2020. The study used national surveillance data from the first 4 months of the campaign.

The campaign began around the time of a surge in SARS-CoV-2 infections in Israel that resulted in a nationwide lockdown on December 27. Additional lockdowns were implemented on January 8, 2021. The country began a phased reopening on February 7 and February 21, 2021, and the lockdown was lifted on March 7.

The number of infections plummeted as vaccinations became widespread, and the authors of the study attributed the decline to the campaign, rather than the lockdown. Indeed, Fauci noted that the number of cases kept falling even as the country reopened.

The variant in Israel, B.1.1.7, is now the dominant variant here, he said. The efficacy of the vaccine stretches across age groups and is 97.5% effective at preventing severe or critical illness and 96.7% effective at preventing COVID-19 deaths.

Fauci also used the example of Qatar, where the vaccine was 100% effective at preventing death from the South African B.1.351 variant, according to another study.

This all boils down to a "race" between the virus and the vaccines, Fauci said.

"If we vaccinate the overwhelming proportion of our population, we will without a doubt be able to crush the outbreak in the same way as we have done with other viral-borne diseases like measles, smallpox, and polio. So the message is, get vaccinated."