The US Centers for Disease Control and Prevention (CDC) has endorsed a new recommendation regarding the timing of the second dose of the Pfizer vaccine. The move comes after a meeting of the CDC's Advisory Committee on Immunization Practices, where members voted unanimously to support the change.

According to the committee, extending the time between doses could result in higher antibody responses and higher vaccine effectiveness. Data from Canada presented at the meeting showed that this approach appears to be safe and effective. The committee also noted that extending the interval between doses may help reduce rates of myocarditis, a condition linked to both Pfizer's and Moderna's Covid vaccines.

The CDC's director, Rochelle Walensky, endorsed the recommendation, encouraging individuals to get vaccinated if they haven't already. She emphasized that the change is not meant to imply that previous dosing schedules were necessarily bad, but rather that ongoing data accumulation allows for refinement of vaccination strategies.

Dr. Matthew Daley, a senior investigator at Kaiser Permanente Colorado, explained that the current dosing schedules were chosen because researchers needed data as quickly as possible. However, he noted that changes to dosing schedules are common and can help make vaccines even safer.

Dr. Helen Keipp Talbot, a committee member and professor of medicine at Vanderbilt University, called the strategy a 'win-win' for both safety and immunogenicity. She added that extending the time between doses may also help convince people who have not yet been vaccinated out of concern about myocarditis to get their vaccines.

The approach could also prove beneficial as new variants of Covid-19 emerge, with Dr. Nicola Klein, a vaccine researcher at Kaiser Permanente Northern California, noting that higher antibodies and more diverse antibody responses will provide better protection against the virus.

Overall, extending the time between doses of the Pfizer vaccine appears to be a safe and effective approach that could lead to improved outcomes for those receiving the vaccine. With the CDC's endorsement, individuals are now encouraged to follow this new recommendation, which could ultimately help combat the ongoing Covid-19 pandemic.

Pfizer vaccine second dose timing