Experts weigh in on common questions about whether and when additional doses of coronavirus vaccines may be needed
By Tanya Lewis
This week the Biden administration announced it would begin offering COVID booster shots to most Americans eight months after their second dose of Pfizer’s or Moderna’s messenger RNA (mRNA) vaccines. Pending authorization from the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention’s vaccine advisory panel, people will start receiving boosters on September 20. Health care workers and nursing home residents will be among the first to be eligible.
The announcement came even as scientists have been debating whether such boosters are needed, who should get them and when they should be administered. It was made less than a week after the CDC recommended that moderately or highly immunocompromised people should receive an additional shot because evidence had emerged that they may not mount an adequate response to two doses. The latest recommendation was issued in light of data from Israel, vaccine makers and several U.S. studies suggesting that vaccine-induced immunity to COVID wanes after six months—and that the vaccines are less effective at preventing mild or moderate disease from the coronavirus’s notorious Delta variant than they were against earlier strains. Two doses of the mRNA vaccines still appear to provide excellent protection against severe disease and death, however.
“If you wait for something bad to happen…, you’re considerably behind your real full capability of being responsive…,” said Anthony Fauci, chief medical adviser to President Joe Biden, in a White House press briefing on Wednesday. “You want to stay ahead of the virus.”https://0182247badce6e700a290e13b6342484.safeframe.googlesyndication.com/safeframe/1-0-38/html/container.htmlADVERTISEMENT
Not all experts are convinced that most healthy people will need boosters. And the World Health Organization has said it is unethical for rich countries to distribute shots to already vaccinated people when so much of the global population has yet to receive a single dose. But the Biden administration has defended its decision, saying the U.S. government should not have to choose between protecting its own citizens and protecting the rest of the world. At the same time, several experts contend that getting more shots in the arms of so far unvaccinated Americans would be a much more effective strategy for protecting the population than administering booster shots to those who are already vaccinated.
Scientific American asked Shane Crotty, a virologist and professor at the La Jolla Institute for Immunology, and Céline Gounder, an infectious disease specialist and epidemiologist at NYU and Bellevue Hospital in New York City and a member of the Biden-Harris Transition COVID-19 Advisory Board, about whether booster shots are warranted and other questions.