The effectiveness of the coronavirus vaccine is deteriorating with time, according to US regulators, who have authorised booster shots for all Americans starting on September 20th, eight months after they have been fully inoculated.
The development comes as scientists and health professionals dispute whether a third injection of the Pfizer-BioNTech and Moderna vaccines would be helpful in combating the Delta strain of Covid-19, which is on the rise.
“The available data make very clear that protection against (coronavirus) infection begins to decrease over time following the initial doses of vaccination, the nation’s top health officials, including Centers for Disease Control and Prevention director Rochelle Walensky and US Surgeon General Vivek Murthy, said in a statement.
“In association with the dominance of the Delta variant we are starting to see evidence of reduced protection against mild and moderate disease,” they added.
The officials warned that while the vaccines remain “remarkably effective” in reducing the risk of severe disease, hospitalization and death from the effects of Covid, protection could diminish in the months ahead without boosted immunization.
“We conclude that a booster shot will be needed to maximize vaccine-induced protection and prolong its durability,” the officials said.
The boosters would be available beginning the week of September 20, with individuals eligible for a shot starting eight months after receiving a second dose of the Pfizer or Moderna vaccines.
The officials said they also anticipate booster shots will be needed beginning later in the year for people who received the Johnson & Johnson vaccine, which rolled out in March.
Over 620,000 people have died in America from coronavirus, with case numbers increasing sharply in recent months due to the spread of the Delta variant.
