The Centers for Disease Control and Prevention released a trio of studies on Friday that erase any doubt that boosters are needed for optimal protection against covid-19. When science changes, policy should adapt accordingly. In this case, the same national effort used to deploy initial vaccinations should now occur for boosters.
One study found that during the omicron surge a booster dose was 90 percent effective at preventing hospitalization, compared with just 57 percent for those who had received two shots and were at least 180 days, or about six months, out from the second dose. The effects are more pronounced when comparing emergency department and urgent-care visits. Receiving a booster was 82 percent effective at preventing these visits, versus 38 percent for vaccinated people without a booster.
Two other studies looked at the likelihood of contracting covid-19. Both found that rates of the coronavirus were lowest among people who were vaccinated and boosted. In one paper that analyzed more than 10 million infections, the unvaccinated had nearly fivefold the incidence of contracting the coronavirus when omicron was predominant, and those with just two doses were 1.7 times more likely to have covid-19 compared to those who had three. In another, the odds of developing symptomatic infection was 66 percent lower for those with three doses versus those with two.
This new research adds evidence that boosters are essential to controlling covid-19. They reduce the chance of infection and therefore the likelihood of transmitting to others. And although two doses still protect against hospitalization and death, effectiveness against severe illness is also enhanced with an additional dose.
Unfortunately, less than half of Americans eligible to receive boosters have done so. Even among adults 65 years and older, more than 36 percent have not been boosted. While three-quarters of the total population have received at least one dose of the vaccine, only one in four are vaccinated and boosted.
Months of mixed messaging are largely to blame. Top health officials, including President Biden’s chief medical adviser, Anthony S. Fauci, and then-director of the National Institutes of Health Francis S. Collins, were correct when they announced in August that most Americans would need boosters. But subsequently, some at the Food and Drug Administration and the CDC repeatedly undercut their authority by questioning the need for boosters. The confusion only worsened when these agencies initially limited additional doses to a narrow subset of the public.
Now, even though boosters are widely available and Biden has been urging Americans to get them, there is a pervasive perception that a third dose is an optional “top up,” as opposed to an essential part of protection. This misconception is leading to unnecessary hospitalization, preventable deaths and greater spread of the coronavirus. Correcting it should be a top policy priority.
To start, it’s well past time for the FDA and CDC to change the definition of the coronavirus vaccine to three doses of the Pfizer and Moderna shots (Johnson & Johnson recipients should receive at least two doses). It’s not at all unusual for vaccines to require three or more shots. The hepatitis B vaccine, for example, is a three-dose series. Polio requires four doses. In time, it might be that the coronavirus vaccine requires four doses or that there could be additional inoculations that target specific variants. But for now, the evidence is clear that it is at least a three-dose vaccine.
Changing the official definition will compel institutions with vaccine mandates to require the additional dose. Already, some nursing homes, employers and universities are starting to require the booster. More should do so, especially since that extra shot reduces the likelihood of infection and therefore transmission to others. Municipalities requiring proof of vaccination for indoor dining, gyms and other venues should also update their regulations. Formal guidance from federal health officials would expedite these efforts and provide a much-needed nudge to increase booster uptake.
In addition, federal health agencies should incentivize doctors’ offices and pharmacies to call their patients who have not yet been boosted. Providers should communicate as much urgency to boost the vaccinated as they have to vaccinate the unvaccinated. It’s also critical to reactivate grass-roots networks of community organizations, local health departments and churches that were so instrumental in initial vaccine outreach.
To be sure, unvaccinated Americans remain the greatest public health concern. But persuading the 30 million or so adults who have not yet had one shot to get one will be extremely difficult. It will be a much easier lift to get an additional dose to the nearly 90 million who already decided to get two shots and are booster eligible. Focusing our efforts to do so is our best hope to protect more Americans and expedite the end of the pandemic.