Safe and effective vaccines continue to be our single best defense against SARS-CoV-2, the virus that causes COVID-19.
Since the early summer, the delta variant of the virus has been the dominant variant circulating in the United States and now represents more than 99% of new cases nationwide. Nearly every corner of the country has experienced high or substantial spread because of delta, which is much more easily transmissible than previous variants.
Scientific studies continue to show that vaccines remain effective in the prevention of serious COVID-19 infections, including those resulting in hospitalizations or death. Vaccines are also effective in preventing infection, but no vaccine is 100% effective and breakthrough infections do occur.
It has been shown that asymptomatic or mildly symptomatic fully-vaccinated people may spread the delta variant to others. Therefore, other prevention measures, including mask wearing in indoor public settings continues to be beneficial, even among fully vaccinated people because of the predominance of the delta variant.
Full vaccination is defined as two doses of an mRNA COVID-19 vaccine, such as Pfizer or Moderna or a single dose of the viral vector vaccine made by Johnson & Johnson. The full effect of vaccination begins two weeks after completion of the last dose. Currently, everyone in the U.S. ages 12 and older are eligible for a COVID-19 vaccine and should seek vaccination at the earliest opportunity.
Recently, the Food and Drug Administration approved the Pfizer vaccine for full licensure in people ages 16 and older. It remains available under emergency use authorization for 12- to 15-year-olds.
People with a moderately to severely weakened immune system benefit from a third dose of either the Pfizer or Moderna vaccine.
This week, the FDA amended its emergency use authorization for the Pfizer vaccine to include a booster dose for certain groups. This was based on the consideration that immunity from the primary series of this vaccine may wane over time, especially for older people.
The Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices reviewed the evidence and issued interim recommendations for a booster dose of Pfizer vaccine (at least six months after the primary two-dose series) for people 65 and older (including long-term care facility residents), and people ages 18 to 64 with underlying medical conditions. As of this writing, the recommendation is pending CDC approval.
The booster recommendation applies to recipients of the Pfizer COVID-19 vaccine only. COVID-19 vaccines (Pfizer, Moderna and Johnson & Johnson) are not considered interchangeable
Moderna has submitted a request to the FDA for authorization of a booster dose, and FDA action is pending review of the evidence. Johnson & Johnson has announced benefit from a second dose but has not yet submitted a request for booster dose authorization to the FDA.
Authorization of COVID-19 vaccines for people ages 5 to 11 is pending FDA and CDC review, but which is expected possibly as early as October.
Dr. Matthew A. Clark is a board-certified physician in internal medicine and pediatrics practicing at the Ute Mountain Ute Health Center in Towaoc.