Karen Lynch

NEW YORK — Now that more Americans are getting vaccinated in the race to build up enough herd immunity to beat the pandemic, questions are mounting as to how long the protection from those shots will last. Along with the unknown duration of immunity the shots offer, there’s also the worry of emerging variants that could threaten the progress made so far in rolling out the vaccines. To that, Pfizer chief executive officer Albert Bourla said it’s likely a third booster shot will be necessary within six months to a year for those fully vaccinated and then perhaps on annual basis, similar to flu shots.

“But all of that needs to be confirmed,” he added. “And again the variants will play a key role. It is extremely important to suppress the pool of people that can be susceptible to the virus because they are vaccinated with high-efficacy vaccines.”

Bourla made his comments during a live Web event sponsored by CVS Health and moderated by CNBC’s Bertha Coombs earlier this month. CVS president and CEO Karen Lynch also took part in the discussion, which covered the ongoing efforts to immunize the rest of the country, including the hesitancy among a considerable percentage of the population to getting the shot.

Albert Bourla

Lynch said CVS continues its efforts to get the vaccine to as many people as possible, starting with creating a call center early on to help people schedule appointments. CVS is also working with community partners, such as churches and the YMCA, to reach the most vulnerable populations and to ensure equity in administering the vaccine, and it has also deployed mobile units to get to as many people as possible.

“We have vaccinated 34% of underrepresented minorities, and that compares to 18% of the total of what the nation has done,” Lynch said. “So we are making very good progress, and our numbers are showing it.”

Pfizer recently reported its vaccine, which it developed with German biotechnology company BioNTech, to be 91% effective after the second dose. Bourla reaffirmed the vaccine’s efficacy, stating that after six months of real-world data the protection from the virus remains “extremely, extremely high,” although that protection, he added, does go down over time.

As Coombs noted, the race to get the country vaccinated is not only a marathon but a sprint at every stage of the marathon, because the virus isn’t the only enemy — so is time. “Even as we have all this great news, we’ve got the vaccine, we’ve got a lot of people vaccinated, but there is an awful lot of concern that even though we’re close to the finish line, we could see a new surge that we can’t really meet because people might resist being vaccinated, or it doesn’t get to every place in the world,” Coombs said. “There are a lot of developing countries that haven’t yet gotten the kind of access that we’re seeing here in the U.S.”

Bourla agreed, which is why he said it was extremely important to convince everyone to get the vaccine by getting the point across that receiving it isn’t just about one’s own health, but the health of loved ones and the community as a whole. In pandemics, Bourla emphasized, you are only as protected as your neighbor, and in this context that neighborhood is the world. “If all of the U.S. is protected, but only very few in Latin America, or very few in Africa, then we’re not protected here. They need to be vaccinated as well,” he said, adding that this is why it’s imperative Pfizer improves its manufacturing capacity.

Bourla expressed optimism that despite the challenges that remain, the end of the pandemic is in sight. In particular, he pointed to the highly effective vaccines — tools, he said, that we “rarely have in medicine.”

However, standing in the way is the hesitancy of many in the population who are unsure about getting the vaccine or, in some cases, simply refusing to. For instance, according a recent survey from the Kaiser Family Foundation, those in “rural” America are twice as likely to say they will “definitely not” get vaccinated as opposed to those living in urban America — and nearly 75% of those who say they will not get the shot either identify or lean Republican.

Adding to the difficulty in getting these Americans vaccinated is that they see it as less of a medical issue and more — 58%, according to the Kaiser survey — as a matter of their civil liberty rather than the health of others. At the same time, many also believe the threat of the pandemic has been heightened by the media.

Data from the Census Bureau’s Household Pulse Survey confirms the problem of vaccine hesitancy, finding that as much as a third of adults in some areas remain skeptical about getting vaccinated, with those rates highest in Wyoming and North Dakota and lowest in Massachusetts, Vermont and California. This data also underscores the split among rural and urban when it comes to the vaccine, showing that in metro areas like Los Angeles, Chicago and New York vaccine hesitancy is low.

The best argument to persuade those who remain wary about getting their shot, in Bourla’s view, is not making it about them but about those they love the most, such as telling young people to get the vaccine for their parents and their grandparents.

“And right now, this is the very critical point to understand — that young people may feel that there are not so many cases of severe disease or deaths at their age, so they don’t need it,” Bourla said. “But they are the people that will transmit it to the others. This is why it is so extremely important that we all work together and that we all feel responsible for doing that, because it affects all of society.”