US' CDC endorses Covid-19 booster jabs for immunocompromised people

US' Centers for Disease Control and Prevention has endorsed the use of an additional dose of COVID-19 vaccine for people with moderately to severely compromised immune systems after an initial two-dose vaccine series.

In a statement, CDC Director Rochelle P. Walensky said it is an "important step" in ensuring everyone, including those most vulnerable to COVID-19, can get as much protection as possible from COVID-19 vaccination.

While people who are immunocompromised makeup about 3 per cent of the U.S. adult population, they are especially vulnerable to COVID-19 because they are more at risk of serious, prolonged illness.

"Emerging data suggest some people with moderately to severely compromised immune systems do not always build the same level of immunity compared to people who are not immunocompromised," the statement read.

Included in CDC's recommendation are people with a range of conditions, such as recipients of organ or stem cell transplants, people with advanced or untreated HIV infection, active recipients of treatment for cancer, people who are taking some medications that weaken the immune system, and others.

On Thursday, the FDA said that the agency was unable to extend the authorization for an additional dose to the Johnson & Johnson vaccine due to insufficient data. Representatives of both agencies said they are "actively engaged" to determine the best course of action for recipients of the Johnson & Johnson vaccine.

Earlier this month, the United States rejected an appeal from the World Health Organization for a moratorium on booster shots to help ease the drastic inequity in dose distribution between rich and poor nations.