The top US health agency on Friday recommended an additional dose of two-shot mRNA Covid vaccines for people with compromised immune systems such as organ transplant recipients, cancer patients or those with advanced and untreated HIV infection.
“At a time when the Delta variant is surging, an additional vaccine dose for some people with weakened immune systems could help prevent serious and possibly life-threatening Covid-19 cases within this population,” said Rachelle Walensky, director of the Centers for Disease Control and Prevention.
The third dose should be the same mRNA vaccine - Pfizer-BioNTech and Moderna - as the primary shots and are to be administered four weeks after completing the primary vaccination.
The CDC has recommended it for those with moderately to severely compromised immune systems: people receiving active cancer treatment for tumours or cancers of the blood; recipients of an organ transplant and are taking medicine to suppress the immune system; recipient of stem cell transplant in the last 2 years or are taking medicine to suppress the immune system; those with moderate or severe primary immunodeficiency (such as DiGeorge syndrome, Wiskott-Aldrich syndrome); advanced or untreated HIV infection; and those being treated with high-dose corticosteroids or other medicines that may suppress their immune response.
An estimated 3% of the adult population in America is said to be immunocompromised. And studies cited by CDC in support of this new recommendation showed 40-44% of hospitalised breakthrough cases - those contracting Covid-19 despite being fully vaccinated - were immunocompromised people.
{{/usCountry}}An estimated 3% of the adult population in America is said to be immunocompromised. And studies cited by CDC in support of this new recommendation showed 40-44% of hospitalised breakthrough cases - those contracting Covid-19 despite being fully vaccinated - were immunocompromised people.
{{/usCountry}}Walensky cited another study to say emerging data suggested immunocompromised people did not develop the same level of antibodies despite the two shots as those with fully functional immune systems. Additionally, the data indicated infected immunocompromised people also transmit the virus to household contacts.
The third dose followed recommendation from CDC’s Advisory Committee on Immunization Practices and modification of emergency use authorisation by the Food and Drug Administration.
There was no word on non-mRNA vaccines such as AstraZeneca’s two-shot vaccine, which retails in India as Covishield, and Johnson & Johnson’s one-shot vaccine.
Israel began administering the third dose of mRNA vaccines in July to healthcare workers and people over 60. But they would be eligible for the third only 5 months after their primacy inoculation. From August 13, Israel also started offering the third dose to those above 50.