The U.S. Food and Drug Administration (FDA) and the U.S. Centers for Disease Control and Prevention (CDC) have both recommended on August 16 that certain immunocompromised people receive a third dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine, indicating that this third dose should be administered at least 28 days after the standard 2-dose regimen of either vaccine is completed.
A CDC advisory panel agreed with the FDA, specifying that the groups of people who should get the booster shot include organ transplant recipients, individuals taking medicine to suppress the immune system, cancer patients undergoing treatment, and individuals with advanced or untreated HIV, among others.
Studies have shown the initial two-dose regimen for the COVID-19 vaccination has lower efficacy in those with weakened immune systems, so another “boost” of the vaccine will likely help immunocompromised people build better protection against the coronavirus. The extra shots were recommended for Pfizer recipients who are 12 or older and Moderna recipients who are 18 and older. The Advisory Committee on Immunization Practices said it would revisit the shots for younger Moderna recipients after the FDA clears the shots for kids.
The agencies did not clear boosters for other fully vaccinated individuals or for recipients of Johnson & Johnson’s vaccine manufactured under its Janssen vaccine division.
Even so, the move to expand additional COVID-19 shots to the wider public in some countries has sparked criticism from WHO officials, since the vast majority of poorer countries are still struggling to get residents vaccinated against the virus, even with first shots. Leaving large parts of the world unvaccinated, WHO officials say, is wasteful, shortsighted, and gives the virus enormous latitude to mutate into potentially more transmissible or virulent variants.
At a briefing this month, the WHO’s Director General, Dr. Tedros Adhanom Ghebreyesus, called for richer countries to stop giving third doses until the end of September. “We cannot — and we should not — accept countries that have already used most of the global supply of vaccines using even more of it, while the world’s most vulnerable people remain unprotected,” he said.