'The only way society gets to reopen safely is if we are all vaccinated'

UC Santa Cruz experts urge all COVID-19 vaccine holdouts to get their shots immediately

Associate Professor of Biomolecular Engineering Rebecca DuBois
Professor of Ecology and Evolutionary Biology A. Marm Kilpatrick 
Associate Professor of Molecular Cell and Developmental Biology Susan Carpenter 


This story is part of UC Santa Cruz's vaccination advocacy campaign, Arm in Arm, which is aimed at communicating to our campus community the importance of the COVID-19 vaccine for a safe reopening of California and UC Santa Cruz.

California now has the lowest rate of COVID-19 infections in the United States.

The San Jose Mercury News reports “a major surge of hope.” The state’s case rate is now less than a third of the United States average. Nonprofit journalism venture CalMatters ran a headline hailing California’s “stunning COVID reversal.”

The news may be encouraging in the nation’s most populous state, but UC Santa Cruz’s COVID experts say this is not the time to slack off when it comes to protecting yourself against the coronavirus. 

They point to a complex reality that lies beneath the optimistic headlines. Variants are surging, U.S. vaccinations are falling from their peak levels, herd immunity is still a distant goal, and there is no sure-fire way of knowing whether others around us have been vaccinated. 

That’s why Associate Professor of Biomolecular Engineering Rebecca DuBois, Professor of Ecology and Evolutionary Biology A. Marm Kilpatrick, and Associate Professor of Molecular Cell and Developmental Biology Susan Carpenter are urging all unvaccinated people to book an appointment to get their shots immediately, and follow CDC safety guidelines even after the vaccinations take effect. 

“The only way society gets to reopen safely is if we are all vaccinated,” Carpenter said. “This virus will continue to thrive and mutate if we let it run rampant through communities. The only weapons we have in our arsenal against this virus are to socially distance, wear our masks, and get vaccinated.”

She likened potential victims of COVID to a water source. Dry up the lake, and watch COVID shrivel up. 

“We need to remove [COVID’s] ability to replicate by removing its reservoir,” Carpenter said. “The sooner we all get vaccinated, the sooner the virus loses places to grow. We are seeing a rise in variants, and if we are not vigilant and keeping a step ahead of this virus we could end up back at the beginning. We do not want this. Right now our vaccines are working against the variants we see arising. Therefore, we are in an active race against the virus, and the only way for us to emerge victorious is to get vaccinated as soon as possible.”

Safety in numbers

Mass vaccinations started in the U.S. on December 14, 2020. DuBois pointed out the vaccination rollouts have been going on long enough to show that the vaccines are “extremely safe and incredibly effective.”

“There have been over 300 million COVID vaccine doses administered in the USA alone, with over 226 million of those doses being the Pfizer-BioNTech or Moderna vaccines,” DuBois said. “If there were safety concerns in those vaccines, we would have seen them by now. There have been over 8 million doses of the Johnson & Johnson vaccine administered.”

DuBois, Carpenter, and Kilkpatrick agreed that the temporary pause on the Johnson & Johnson vaccine was necessary while the U.S. Food and Drug Administration and Centers for Disease Control and Prevention (CDC) reviewed six reports of blood clots among people vaccinated with the J & J shot in the United States.  

“I think people should view this type of scrutiny as a reassuring and positive thing, knowing that any safety concerns at all, even a possible one in a million event, is investigated thoroughly,” DuBois said. 

In a new report, the CDC said the blood-clot side effect is extremely rare, “occurring at a rate of about 7 per 1 million vaccinated women between 18 and 49 years old," the CDC wrote. "For women 50 years and older and men of all ages, this adverse event is even more rare."

DuBois praised the Johnson & Johnson vaccine for its one-dose formulation and its ability to be stored in a refrigerator rather than an ultra-cold freezer like the Pfizer and Moderna vaccines, which will enable its distribution to hard-to-reach individuals or those who lack the ability to schedule two appointments for inoculation.

For all three vaccines now available in the U.S., the protection from COVID-19 greatly outweighs the risks of severe side effects, said Kilpatrick, who emphasized personal safety and economics as compelling reasons to get vaccinated.

“Vaccines greatly reduce the chance of getting sick and dying, and also reduce the chance of transmitting the virus to someone else," he said. “Reducing transmission in the community is our fastest and best way to restore our society economically and socially.” 

DuBois emphasized civic pride and social responsibility as reasons to get vaccinated, along with a desire for more personal freedom. 

“Getting a vaccine is a great way to show that you care about your community," DuBois said. “In addition, it is your opportunity to safely start doing your favorite things again. I got my vaccine and got to give my 92-year-old grandma a big hug.” 

Even those who have recovered from COVID-19 should get vaccinated, DuBois said. 

“Scientists are generally observing higher levels of antibodies in vaccinated people compared to people who were naturally infected," she said. "So there is still a benefit to getting the vaccine, even if you had COVID in the past."

Is herd immunity within reach? 

A strong messaging campaign is essential to achieving herd immunity, Carpenter said. 

“The only way we get back to 'normal' is to achieve herd immunity worldwide,” she said. “Therefore we need everyone to take the vaccine. The data shows that these vaccines are safe, and we see in Israel where over 50% of the population has been vaccinated just how effective their vaccine campaign has been. In Israel, society is reopened and their case rate is staying very low. This should encourage all those who are hesitant that we can get back to normal if we get vaccinated.”

But in this stage of the pandemic, herd immunity remains an elusive goal, according to scientists and public health officials interviewed for a recent New York Times article.

 Carpenter agreed that  “the numbers of people who are refusing to be vaccinated are going to inhibit the United States in getting to herd immunity anytime soon, if ever, as the article states,” she said. “I think it's the unfortunate reality we are facing. 

It is very frustrating as the only way the pandemic ends is if we reach herd immunity, so trying to get that message out there is important.” 

Kilpatrick agreed that human behavior will play a strong role in whether the United States achieves herd immunity. 

“The herd immunity threshold, when the fraction of people that are immune is high enough so that each person infects, on average, less than one other person, can definitely be reached by a combination of vaccination and infection, but it's worth noting that the threshold level changes as social patterns change,” Kilpatrick said. “If we stop wearing masks and resume pre-pandemic social behavior then the threshold will be much higher than if we maintain some pandemic measures.

“In some communities, even with pre-pandemic behavior, vaccination may keep immunity above the level needed to prevent the virus from being sustained locally, whereas in others lower vaccination will allow for low to moderate levels of transmission until infection leads to immunity increasing to the threshold in that community,” Kilpatrick said. 

The common thought among scientists is that we will not reach herd immunity to the point where this virus disappears entirely, DuBois said.

“Even if the USA becomes mostly vaccinated, the rest of the world has a long way to go, so the virus will continue to spread globally,” DuBois said. “People should not be holding out hope that the virus will simply disappear—it will keep coming back into our community and infecting susceptible individuals. However, I do think we will eventually reach a point where the majority of Americans have some level of immunity, preferably via vaccination and not natural infection, and there will be fewer cases of severe disease.” 

Taking precautions 

The three COVID experts agree that people should also take measures to avoid getting infected if they frequently have contact with unvaccinated people.

“Protection from vaccination— one dose for J&J or two doses for Pfizer or Moderna—against symptomatic and severe disease and death is relatively high,” Kilkpatrick said, noting that the vaccines are  70–95% effective against symptomatic disease. 

“Data is less robust for more severe disease, but protection is likely similar or possibly higher," he said. "But that protection rate is definitely not 100%." 

As a result, people should still take measures to avoid becoming infected, and should adjust their own behavior to reflect their specific risk of severe disease and death that increase enormously with age and substantially with preexisting conditions.

Kilpatrick also noted that the vaccines are 60–90% effective when it comes to reducing the chance of an infected person transmitting COVID to another person. That’s a very significant amount of protection, but it still leaves room for vigilance, he said. 

“Wearing masks in public is an important way to reduce the chance of becoming infected or transmitting the virus if people are indoors,” Kilpatrick said. "Outdoors, masks are important if people are having close contact with other people.” 

Many Americans have celebrated the recently updated CDC guidelines, listing more activities that vaccinated individuals can safely resume. For example, the agency recently eased face mask guidelines for fully vaccinated people outdoors. 

“But we are not yet at the point where every adult has had the ability to get their full course of a vaccine ,” DuBois said. “Until then, it is still important to wear masks.”

“We need to encourage the culture of mask wearing until this pandemic is over,” Carpenter said. “We do not know who has been vaccinated and who has not. Also remember no one under 16 has been vaccinated yet, and so I think we should be setting an example for our children and continue to wear masks until we know it is safe."

Bad information 

Though the vaccine rollout has been impressive, with around 100 million Americans fully vaccinated, misinformation on vaccines and vaccine safety remain widespread and damaging, the experts agreed. 

"Countering this misinformation is difficult because people often don't seek out other information,” Kilpatrick said. “For example, people who identify as politically conservative are currently less likely to get vaccinated. There are some strategies that appear to be effective in reaching a subset of the population that currently is not choosing to get vaccinated, but it is time-consuming and challenging. This is one of the biggest current challenges in ending the pandemic in the U.S.”

Carpenter would like to believe that anyone could be persuaded to take the vaccine when presented with the facts. All scientists and medical professionals have a moral responsibility to work against misinformation, listening to people's concerns and providing them with information to help alleviate them, Carpenter said. 

“Engaging at a local level will be important,” she said.

For those who are vaccine hesitant, “it can be helpful for them to know that their friends, family, colleagues, or other trusted individuals received the vaccine," DuBois said. "So spread the word and celebrate when you get your shot."

Find information and locations to receive your COVID-19 vaccination on the UCSC Student Health Center website

Download an Arm in Arm Zoom background from the UC Santa Cruz Communications & Marketing website