ACIP Vaccine Update

FDA approves Pfizer COVID vaccine, allows extra vaccine dose for certain immunocompromised individuals

The FDA recently fully approved the Pfizer COVID-19 vaccine and also approved an additional vaccine dose for immunocompromised people following a primary vaccine series.

Two major actions by the FDA this month have rapidly changed the status of COVID-19 vaccination in the U.S. On Monday, the FDA granted full approval to the Pfizer-BioNTech COVID-19 vaccine for those age 16 and older. Also, in a unanimous vote on Aug. 12, the FDA allowed for the use of an additional dose of approved COVID-19 vaccines in certain immuno-compromised individuals, specifically, solid organ transplant recipients or those diagnosed with conditions that are considered to have an equivalent level of immunocompromise.

An additional dose of Pfizer-BioNTech COVID-19 (12 years of age and older) or Moderna COVID-19 vaccine (18 years and older) is recommended following a primary series in immunocompromised people.

The immunocompromised population includes those receiving active or recent treatment for solid tumor and hematologic malignancies, recipients of solid-organ or recent hematopoietic stem cell transplants, those with severe primary immunodeficiency, advance or untreated HIV infection, those receiving active treatment with high-dose corticosteroids, alkylating agents, antimetabolites, tumor-necrosis blockers, and other biologic agents that are immunosuppressive or immunomodulatory, and those with chronic medical conditions such as asplenia and chronic renal disease that may be associated with varying degrees of immune deficit.

The CDC’s Advisory Committee on Immunization Practices (ACIP) met on Friday, Aug. 13, to discuss further clinical recommendations. Stanley E. Grogg, DO, the AOA’s liaison to the ACIP, has shared additional relevant information about the vaccine and the emergency meetings with the AOA. Here is an edited summary of his report from the Aug. 13 meeting.

Intervention: Additional dose of mRNA

  • Attempts should be made to match the additional dose type to the mRNA primary series. However, if that’s not feasible, a heterologous additional dose is permitted
  • The additional dose should be administered at least 28 days after the completion of the primary series
  • Even after receiving the third dose, immunocompromised people should continue to wear a mask, practice social distancing and avoid crowds and poorly ventilated spaces

Benefits of third mRNA vaccine

  • Enhanced antibody response
  • Increase in proportion of people who respond to the COVID-19 vaccine

Possible harms of third mRNA vaccine

  • In small studies, no series adverse events were observed
  • mRNA COVID-19 vaccines are associated with rare but series adverse events, including anaphylaxis as well as myocarditis and pericarditis in young adult males

Delta variant: What we know

  • Nearly twice as contagious as previous variants
  • Some evidence of increased illness severity vs. previous strains in unvaccinated persons
  • Greatest risk of transmission still among unvaccinated people
  • Fully vaccinated people with Delta breakthrough infections can spread the virus to others. However, vaccinated people with Delta appear to be infectious for a shorter period than unvaccinated persons with Delta

Vaccine statistics

As of Aug. 11, 58.9% of the U.S. population were fully vaccinated. A total of 353,205,544 doses had been administered.

Work group interpretation of booster doses

  • Neutralizing antibody data will be important for booster dose discussions, but may not represent the entire immune response to COVID-19 vaccines
  • Based on available data and timing of vaccine roll-out, initial booster vaccine policy focused on at-risk adult populations. This could include: adults 65 years old or older; LTCF residents and healthcare personnel

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