U.S. health officials are considering new changes to vaccine guidance that would lengthen the amount of time between doses to lower the risk of heart inflammation for immunocompromised people. The CDC told a panel of outside advisers on Friday these proposed changes would apply to the Moderna and Pfizer vaccines.
Immunocompromised people, who generally don’t respond to vaccines, are the only population advised getting four vaccine jabs. CDC guidance suggests this group should receive three vaccine doses within two months and the fourth dose around five months after the third. The CDC recommends that immunocompromised people get their fourth shot as soon as three months after the third.
This update would apply to people aged 18 and up who received the Moderna or Johnson & Johnson vaccine and those aged 12 and up who received Pfizer. During Friday’s presentation, Dr. Sara Oliver, a CDC official, said that an extended interval appears to reduce the risk of myocarditis. She also said the risk of heart inflammation is lowered if the vaccines are given eight weeks apart.
Although rare, myocarditis is a side effect seen in the Pfizer and Moderna shots and appears to be most familiar with young men. Most cases are mild and resolve quickly. According to Oliver, some 33 million people in the U.S., between the ages of 12 and 39, remain unvaccinated.