People who were previously infected with Covid should eventually get vaccinated against the disease as their immune protection will likely wear off over time, said Dr. Scott Gottlieb told CNBC on Wednesday.
“The immunity conferred by a natural infection appears to be robust and permanent. We know it lasts at least six months, probably longer,” the former Commissioner of the Food and Drug Administration told the Squawk Box.
“My guess is that it won’t last. At some point these people will have to get vaccinated,” added Gottlieb, who is now on the board of directors of the vaccine manufacturer Pfizer.
A key question about natural immunity is whether a more severe Covid case will result in higher quality protection compared to a person who has remained asymptomatic, for example.
“With SARS and MERS we saw that people who got more sick had more permanent immunity. We don’t know if this is the case with this SARS-CoV-2 virus, but it could be,” said Gottlieb and was referring to two other types of coronavirus – Severe Acute Respiratory Syndrome and Middle East Respiratory Syndrome – that caused outbreaks in several countries.
SARS was first discovered in 2003, while MERS was first reported in 2012, according to the World Health Organization. The SARS and MERS outbreaks were nowhere near as widespread as SARS-CoV-2, the virus that causes Covid-19, with very few US cases. They only caused a fraction of the deaths as Covid-19. However, both were far more deadly.
Gottlieb’s comments on Wednesday follow recent studies looking at immunity to previous Covid infections compared to those who received a Covid vaccine.
A study conducted in Israel found that a 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 reviewed by experts.
A study in Great Britain, on the other hand, comes to a different conclusion, which has also not yet been assessed. “The effectiveness of two doses remains at least as great as the protection offered by a previous natural infection,” the researchers write. Unlike the Israeli publication, participants in this study included recipients of the two-dose vaccines from AstraZeneca and Moderna in addition to Pfizer.
“I think it’s overall unclear whether vaccination-induced immunity is better, a little better, or a little worse than” natural immunity, Gottlieb said.
Pfizer’s vaccine was fully approved last month by the FDA, which is still considering the use of Moderna as part of an emergency clearance in the US for full approval. AstraZeneca has not received an EUA in the US Johnson & Johnson’s single vaccine, the only other vaccine administered in the US, has been approved for emergency use. J&J has yet to receive full FDA approval.
Gottlieb acknowledged that the data also shows that vaccination protection decreases over time. The US is currently giving a booster dose to people with compromised immune systems to counteract this – and later this month a wider segment of the population will be eligible for an extra dose.
“You can re-administer a vaccine. You don’t want to re-administer an infection,” said Gottlieb, who headed the FDA in the Trump administration from 2017 to 2019. “In order to achieve infection-induced immunity, you actually have to get the infection, which we actively want to avoid.
Nearly 62% of the US population have received at least one dose of Covid vaccine, while 52.4% are fully vaccinated, according to data from the Centers for Disease Control and Prevention.
Health officials, politicians, and business leaders have urged more Americans to get a Covid vaccine. A number of companies and other institutions, such as universities, are implementing strict guidelines on compulsory vaccination in hopes of convincing reluctant people to take the life-saving injection.
Some unvaccinated Americans may believe that their previous coronavirus infection provides sufficient protection from the disease that they feel no urgency to get the vaccine. However, Gottlieb’s statements on Wednesday complement his previously expressed view that previously infected people who are then vaccinated have “the best of both worlds”.
“At least one dose gives you a broad, very deep, very lasting immunity based on the data we’ve seen so far,” Gottlieb said on July 6th on CNBC. “So there are still many compelling reasons why you might want to get vaccinated even if you’ve been infected.”
Disclosure: Scott Gottlieb is a CNBC employee and a member of the board of directors of Pfizer, genetic testing startup Tempus, health technology company Aetion Inc., and biotechnology company Illumina. He is also co-chair of the Healthy Sail Panel of Norwegian Cruise Line Holdings and Royal Caribbean.