Israel initially led the world with a rapid vaccination campaign and 57 percent of its population is fully vaccinated. But the arrival of the highly contagious Delta variant has brought a rise in daily infections, up from single digits a month ago to an average of 452 cases per day. About 58 percent of the 81 Israeli Covid-19 patients currently hospitalized are vaccinated, according to Israeli Ministry of Health data. Studies suggest that vaccines remain effective against the Delta variant.
Health care providers in France have been giving a third dose of a two-dose vaccine to people with certain immune conditions since April.
The number of organ transplant recipients who had antibodies increased to 68 percent four weeks after the third dose, up from 40 percent after the second dose, one team of French researchers recently reported. In the United States, there has been no concerted effort by federal agencies or vaccine manufacturers to test this approach so far.