by Michael Daignault, MD, and Monica Gandhi, MD, MPH: For Complete Post, Click Here…
The safety and effectiveness data should prompt CDC to update its policy.
On Friday, February 4, the Advisory Committee on Immunization Practices (ACIP) quietly acknowledged the rapidly accumulating body of evidence supporting an extended interval between the first and second dose of a two-dose COVID-19 vaccine series. ACIP members weighed the benefits of extending the interval between doses of the two mRNA vaccines — currently 3 weeks for Pfizer (Comirnaty) and 4 weeks for Moderna (Spikevax) — to 8 weeks, based on both effectiveness and safety data. Updating the guidelines would represent a seismic policy shift in this country.
We welcome the long-overdue recognition of this evidence-based approach already endorsed by multiple other countries including Canada, India, the U.K., and other countries in Europe. Although the two-dose series of the Pfizer vaccine was studied at an interval of 3 weeks and the Moderna vaccine at an interval of 4 weeks, the companies were aware of the urgent global need for an effective COVID-19 vaccine while designing these interval strategies. Except for rabies, no other vaccine is given at a dosing interval of 3 weeks. In fact, a principle of vaccinology is that priming the immune system with the first dose generates good responses to second doses of most vaccines for at least 6 months or more.
There are three main lines of evidence for extending the COVID-19 vaccine dosing interval: 1) immunologic; 2) vaccine effectiveness studies; and 3) safety studies regarding the low risk of myocarditis with mRNA vaccines.
Michigan Voices for Better Health 