In two unanimous decisions, a 15-member expert panel convened by the Centers for Disease Control and Prevention (CDC) today recommended booster doses for people who have been vaccinated with either the Moderna or Johnson&Johnson-Janssen COVID-19 vaccines. This advice will be taken into account by Dr. Rochelle Walensky, Director of the CDC before she makes a final recommendation.
The CDC’s Advisory Committee on Immunization Practices (ACIP) recommends that anyone who was initially vaccinated with the Moderna shot get a booster at least six months later, while the committee recommends that J&J-Janssen recipients receive a booster at least two months after their initial vaccination. The endorsement follows a similar decision from an expert Food and Drug Administration (FDA) panel that allows people to receive any of the three authorized or approved COVID-19 vaccines, from Pfizer-BioNTech, Moderna and J&J-Janssen, as the booster dose. Moderna will provide half of the dose as the original.
This decision will only apply to people who were vaccinated against COVID-19. This includes people older than 65 years old, and those aged between 18-24 who may be at greater risk due to their underlying medical conditions. Health care workers, supermarket workers, teachers, and people who live in long-term facilities or shelters for the homeless are all examples.
The FDA and CDC had previously approved a Pfizer BioNTech booster vaccine. This decision replaces and incorporates that authorization. As with the previous discussion about boosters, the 15-member committee were relatively agreed on two things: that due to the lower efficacy of J&J-Janssen’s vaccine, people who got that shot should receive a booster; and that for people vaccinated with the two mRNA vaccines from Pfizer-BioNTech and Moderna, those over age 65 and anyone with underlying health conditions, regardless of their age, should get a booster dose. It was discussed whether a booster dose should be given to younger adults whose lives or jobs pose a greater risk.
Dr. Sarah Long, professor of pediatrics at Drexel University College of Medicine, asked “what available evidence is there that people under age 50 should receive a booster at this point?” When the committee discussed this population at the meeting when they decided on the Pfizer-BioNTech booster, they voted against recommending boosters for those under 50. Walensky decided that people between the ages of 18 and 64 could have the opportunity to get a booster if they are high-risk of being exposed to occupational or institutional hazards. This final decision states that such groups may, and should, be able to get a boost if they choose.
“The last decision made in this regard is not the correct decision,” Long said, referring to today’s final recommendation. “And we are somewhat stuck with it. I can’t say that I am comfortable that anybody under age 50—otherwise healthy individuals—needs a booster at this time, either with Moderna or Pfizer-BioNTech.” Long noted that the data for this age group aren’t as strong as for older individuals or those with underlying health conditions, and said that the authorization implies “smoke and mirrors and underhanded winks and nods.”
Long voted for a booster, but this was after Long and other members had discussed the necessity to remind doctors about the fact sheets and the clinical guidance. In particular, this information will caution that the need for a booster, especially among younger people, should be carefully weighed against rare but known side effects, which include inflammation of the heart tissue in the case of the mRNA vaccines, and blood clots and Guillain-Barre Syndrome for the J&J-Janssen shot.
The FDA and CDC evaluated data from vaccine makers and found that the mRNA vaccinations still provide effective protection against severe COVID-19, but their effectiveness in protecting people is decreasing. The unanimous decision reflected that committee members acknowledged that some people would not need boosters from an immunological perspective. However, from a public health standpoint authorizing boosters to protect people from the continuing pandemic is the best option.
With the recommendation, it now falls to providers—pharmacists, doctors, community health care workers and school nurses—to figure out how to roll out booster doses. After the Pfizer-BioNTech booster authorization, Walensky noted that most vaccinators will be relying on people to self-attest that they fall into one of the eligible groups, and that they won’t be requiring documentation or other proof of medical conditions or age.
Administering the boosters will be complicated, since Moderna’s booster is a half dose, and both patients and doctors will likely try to game the one study that evaluated so-called mixing and matching of boosters to figure out which one will provide the greatest protection. Co-lead researcher of this study by the National Institute of Allergy and Infectious Diseases spoke to the panel. She stressed that the trial wasn’t meant to evaluate different combinations of boosters but was designed to prove that mixing boosters is both safe and efficient. Still, that data, which included more than 450 people, suggested that those who were originally vaccinated with a single dose of J&J-Janssen’s shot enjoyed the greatest increase in protection in the form of virus-fighting antibodies if they received a Moderna booster. The panel members also discussed the fact that given the risk of clotting events, especially among younger women vaccinated with J&J-Janssen, providers might consider boosting this population with an mRNA vaccine.
Further complicating matters is the FDA’s and CDC’s approval of a third dose mRNA vaccines in August for those with weakened immune systems. They aren’t considered booster doses. These additional doses will be used to strengthen their immune system as part of the primary COVID-19 vaccination. The committee discussed that under the current booster authorization these patients too would be eligible for booster shots at the appropriate time, which would mean a fourth dose for people originally vaccinated with an mRNA shot and a third dose for those getting J&J-Janssen.
Dr. Grace Lee, chair of the ACIP committee, said that it’s up to providers to educate themselves and the public about the complicated booster recommendations, and to make sure that those who really need them get them and benefit from the enhanced protection. “Our recommendation is just one step along the way,” she said. “It’s important for us to make sure in our implementation that patients are truly educated about the benefit-risk balance based on their own personal situation. It’s the hardest thing for us to do, but I encourage all of us to go beyond these recommendations and do our best to educate our communities and provider teams, and partner with public health.”
The fact that mixing doses appears to be both safe and efficacious could help support the U.S. government’s booster campaign as well. Smaller doctor’s offices or community clinics, or mobile units that go into long-term care facilities, for example, won’t have to store all three vaccines, but instead could focus on one, streamlining the logistics of their vaccination efforts. After the FDA and CDC approved it, the White House stated that they have purchased enough booster doses to send them out.