Navigating the Omicron Hype: The Latest on Boosters

Volume 10, Issue 2

The last 10 days have been rocked by the discovery of the Omicron variant, which may be more infectious than previous strains and render some vaccines ineffective. While the data on this variant is very preliminary, several signals have emerged in the last few days that warrant coverage in this column.

In this week’s issue of Talking Therapeutics, we explore how the Omicron variant affects the current vaccination strategy, and we’ll cover a few critical questions that will be essential for pharmacists to know in order to advise patients accordingly.

Point 1: Boost Now!

Unsettling data from South Africa was published Tuesday. In this preliminary data from 6 uninfected patients who were vaccinated with two doses of the Pfizer vaccine, the efficacy of their antibodies against Omicron was reduced to one-fortieth the potency of that against an earlier strain of the virus.

This suggests that breakthrough infections for this group would occur much more frequently with the new variant. The risk of patients developing severe complications or dying remains unknown.

Interestingly, the same study reported on 6 other patients who were infected with and survived COVID-19 prior to vaccination, and these patients maintained a strong antibody response against the Omicron variant.

Yesterday, Pfizer and BioNTech released data showing that patients who received a third dose of their vaccine had neutralizing antibody levels against the Omicron variant that were comparable to those against previous variants after two doses.

Of note, these data were generated one month after the third shot, so the potential for waning immunity over time after one month cannot be excluded. Data on actual protection against Omicron—as measured by hospitalization and death due to infection—are also not available for the third booster dose.

Taken together, these emerging data point towards immediately administering booster doses for most patients. Pharmacists need to be aware of this point, as some patients may want to wait for an Omicron-specific booster that the companies have discussed developing in 2022. Patients should not wait for such a booster to be developed, and instead should immediately take a booster of any available vaccine.

Point 2: Mix and Match if Possible

The data continues to accumulate showing that mixing and matching vaccines can produce a stronger antibody response. A recent blog post published by Northeastern said the following:

“Two weeks after a booster shot, people who had initially gotten a [Johnson & Johnson (J&J)] shot and followed it with a Moderna booster had average antibody levels that were 9.8 times higher than those who had gotten two J&J shots. Those who got a Pfizer-BioNTech booster were close behind…As for the mRNA combinations, the volunteers who had received three doses of Moderna had the highest antibody levels found in the study. Participants who got a Moderna booster after the two-dose Pfizer-BioNTech series ranked a close second. Those who started with Moderna and boosted with Pfizer-BioNTech had the third highest antibody levels.”

Finally, data from a small study of 65 volunteers found that boosting two Pfizer doses with a J&J vaccine resulted in more sustained antibody titers compared to a third Pfizer dose.

The take home message for pharmacists must clearly remain that patients should still prioritize receiving any booster shot over shopping for a specific one. But we can also educate patients that they do not have to seek out a specific shot to avoid mixing and matching, given that doing so may actually be a better option.