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Older Americans Should Get Another Covid Shot This Spring, Panel Says

Study of Patients With a Chronic Fatigue Condition May Offer Clues to Long Covid

Feeling Terrible After Your Covid Shot? Then It’s Probably Working.

After Giving Up on Cancer Vaccines, Doctors Start to Find Hope

Why a Century-Old Vaccine Could Be the Next Weapon Against Viruses

Why Monkeypox Vaccine Shortage May Threaten the Immunocompromised

Why a Coronavirus-Flu ‘Twindemic’ May Never Happen

How the Coronavirus Steals the Sense of Smell

Starting later this week, some at-risk Americans become eligible for a 4th Covid shot.

Studies Suggest Why Omicron Is Less Severe: It Spares the Lungs

Most of the World’s Vaccines Likely Won’t Prevent Infection From Omicron

Omicron Variant Spreading Twice as Quickly as Delta in South Africa

Omicron Prompts Swift Reconsideration of Boosters Among Scientists

Pfizer and Moderna shots are less effective in people with weak immune systems, a study finds.

Starting next year, some immunocompromised people may receive a fourth Covid vaccine dose, the C.D.C. says.

Pregnant and breastfeeding women are slower to respond to vaccination, researchers report.

C.D.C. Panel Recommends Covid Booster Shots for Millions of Americans

Mix-and-Match Covid Boosters: Why They Just Might Work

What Scientists Know About the Risk of Breakthrough Covid Deaths

Here is what scientists know about the risk of breakthrough Covid deaths.