Leaders and health officials in wealthier countries, on the other hand, are setting aside doses for more vulnerable people who may require additional doses to protect themselves from the virus.
In the United States, Biden administration officials have already begun developing a plan to begin administering third doses of the Pfizer and Moderna vaccines as early as this fall, claiming that the logistics are too complicated to wait for scientific confirmation that the extra doses are truly necessary.
Full vaccination is highly effective at protecting against severe disease caused by the virus, but it is unclear when additional doses may be required for certain groups. Boosters are required for some vaccines to remain highly protective.
In the US, federal officials last week approved a third dose of the Pfizer and Moderna vaccines for people whose immune systems have been compromised due to organ transplants, chemotherapy, or other medical conditions.
However, officials from the Food and Drug Administration and the Centres for Disease Control and Prevention stated that authorising third doses for immunocompromised people was a separate issue from whether booster doses were required for the general population.
Pfizer and BioNTech have pushed for the approval of third doses of their vaccine to be granted as soon as possible, but US officials said in July that they would need more data, possibly months’ worth before they could answer the question.
On Monday, the companies announced that they had given the Food and Drug Administration data from phase 1 of their clinical trial, indicating that a third dose was safe and significantly boosted recipients’ immune response to the virus, including the Delta variant. Some people have decided to take matters into their own hands.
A little more than a million people in the United States who received a two-dose vaccine have already received a third dose, according to Dr Kathleen Dooling, a C.D.C. official, on Friday. It was unclear how many were immunocompromised.
Some countries, including France, Germany, and Israel, have legalised booster shots for the elderly. Israel announced on Friday that the age for receiving a third dose would be reduced to 50.
World Health Organization officials argue vehemently that booster programmes will further deprive low-income countries of desperately needed vaccines.
W.H.O. officials argue that leaving large swaths of the world unvaccinated is wasteful, short-sighted, and gives the virus enormous leeway to mutate into potentially more transmissible or virulent variants.
The distribution of vaccines around the world has been wildly unequal. According to the Our World in Data project at Oxford University, many countries in North America and Europe have at least partially vaccinated more than half of their populations, compared to barely more than 4% of Africa’s population.
