Dr. Scott Gottlieb on why Covid breakthrough cases are happening


CNBC Television

CNBC’s “Squawk Box” team discusses Covid booster vaccines, FDA officials stepping down and children’s vaccine approval with Dr. Scott Gottlieb, former FDA commissioner.

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People who previously were infected with Covid-19 should eventually get vaccinated against the disease because their immunity protection will likely wane over time, Dr. Scott Gottlieb told CNBC on Wednesday.

“The immunity conferred by natural infection seems to be robust and seems to be durable. We know it lasts at least six months, probably longer,” the former commissioner of the Food and Drug Administration said on “Squawk Box.”

“My hunch is it’s not going to last in perpetuity. At some point, those individuals are going to need to get vaccinated,” added Gottlieb, who now serves on the board of vaccine maker Pfizer.

A key question remaining about natural immunity is whether having a more severe case of Covid, compared with someone who remained asymptomatic, for example, leads to higher-quality protection.

“With SARS and MERS, we saw people who got more sick ended up having more durable immunity. We don’t know if that’s the case with this SARS-CoV-2 virus, but it might be,” Gottlieb said, referring to two other types of coronaviruses — severe acute respiratory syndrome and Middle East respiratory syndrome — that caused outbreaks in multiple countries.

SARS was first detected in 2003, while MERS was initially reported in 2012, according to the World Health Organization. The SARS and MERS outbreaks were not nearly as widespread as SARS-CoV-2, the virus that causes Covid, with very few U.S. cases. They caused a limited number of deaths when compared with Covid. However, they were both far more deadly.

Gottlieb’s comments Wednesday follow recent studies that have examined immunity from prior Covid infections versus those who received a vaccine for the disease.

One study conducted in Israel found that natural infection offered “longer lasting and stronger protection” against the highly transmissible coronavirus delta variant than Pfizer’s two-dose Covid vaccine. It has not yet been peer-reviewed.

By contrast, a study in the U.K., which also hasn’t been peer-reviewed yet, arrived at a different conclusion. “Effectiveness of two doses remains at least as great as protection afforded by prior natural infection,” the researchers wrote. Unlike in the Israeli paper, participants in this study included recipients of AstraZeneca’s and Moderna’s two-dose vaccines, in addition to Pfizer.

“I think on the balance it’s unclear whether vaccine-induced immunity is better, slightly better, slightly worse, than” natural immunity, Gottlieb said.

Pfizer’s vaccine was fully approved last month by the FDA, which is still considering the application of Moderna, currently under an emergency use authorization in the U.S., for full approval. AstraZeneca did not receive an EUA in the U.S. Johnson & Johnson’s single shot, the only other vaccine given in the U.S., was cleared for emergency use. J&J has yet to apply for full FDA approval.

Gottlieb acknowledged that data shows vaccine protection declines over time, as well. The U.S. is currently administering booster shots to people who have weakened immune systems to counteract that — and later this month, a broader swath of the population will become eligible for an additional vaccine dose.

“You can redose a vaccine. You don’t want to redose an infection,” said Gottlieb, who led the FDA from 2017 to 2019 in the Trump administration. “To acquire infection-induced immunity you have to actually get the infection which is something that we want to try to actively avoid, so getting a vaccine has a lot of elegant attributes in that regard.”