What do COVID-19 vaccines mean for daily life in the months ahead?

As more COVID-19 vaccines show signs of being able to protect people from getting really sick, they’re fueling hopes that some sense of normalcy is within reach. Two vaccines have been authorized for emergency use in the United States and are slowly getting into arms across the country. And two more vaccine makers have just reported fairly positive results — a crucial step on the path toward adding tools to quell the pandemic.

As a result, people are looking forward to finally being able to safely hug loved ones, travel and go to work, school or the store without fear of falling ill. But the rocky vaccine rollout across the country — plus ensuring enough people are vaccinated to reach herd immunity and slow the virus’ spread — means it’s likely going to take time for such hope to become reality (SN: 10/19/20). Exactly how much time is unclear, though public health experts have said it may take until late summer or fall.   

Still, every shot means that the person who received it is less likely to get sick. And every vaccinated person, along with continued public health measures like wearing masks, brings us one step closer to the end of the pandemic and a breath of relief.

Amidst the whirlwind of information about the peril and promise of COVID-19 vaccines, here are answers to some commonly asked questions about the shots.

How many different vaccines are there in the United States?

Two mRNA vaccines — developed by Pfizer/BioNTech and Moderna — are making it into arms across the United States. And the shots could soon be joined by at least one or two others.

Novavax announced January 28 that its vaccine has 89.3 percent efficacy against COVID-19, according to a Phase III clinical trial in the United Kingdom. However, that vaccine is less effective against a coronavirus variant that has emerged in South Africa (SN:1/28/21).

And Johnson & Johnson announced on January 29 that its vaccine had an efficacy of 72 percent against moderate to severe COVID-19 in the United States. That vaccine is also less effective against preventing that level of sickness in people exposed to the variant from South Africa, though it did prevent deaths (SN: 1/29/21).

Johnson & Johnson plans to submit applications for emergency use authorization to the U.S. Food and Drug Administration in early February. It is unclear whether Novavax will do the same, as the company’s clinical trial in the United States is ongoing.   

The FDA said the mRNA vaccines were safe when it OK’d their use. Is that still true?

Yes. Health experts have been watching newly vaccinated people closely and so far, the vaccine has proven safe.

“We really have to weigh [vaccine risks] against a very imminent risk [of] becoming infected and becoming sick with this virus that is circulating everywhere,” says Natalie Dean, a biostatistician at the University of Florida in Gainesville. And so far, both Moderna’s and Pfizer’s vaccines come with low risks compared with those of COVID-19.

The FDA required vaccine developers to have two months of safety data from clinical trials before applying for emergency use authorization. The vaccines do have some side effects, including fever, arm soreness, redness at the injection site, headache and feeling sick. Such symptoms are not unexpected, as they are a sign that the immune system is kicking into gear and are common side effects for vaccinations in general.

Some people have had severe allergic reactions to Pfizer’s and Moderna’s vaccines. But all were quickly treated and none died.

Two U.S. Centers for Disease Control and Prevention–led studies found that both vaccines have higher rates of allergic reactions — 11.1 cases per 1 million vaccine doses for Pfizer’s and 2.5 cases per 1 million vaccine doses for Moderna’s — than allergic reactions to the flu vaccine, which is 1.3 cases per 1 million doses. Still, such reactions are “exceedingly rare,” Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory diseases said in a Jan. 6 news briefing (SN:1/6/21).

Why is it so hard to get a vaccine?

Vaccine distribution in the United States has been plagued with problems. Not only are limited doses available to people in currently eligible groups but everyone who gets Moderna’s or Pfizer’s vaccines needs two shots for full protection (SN: 12/3/20).

The logistical issues also come in part because each state — sometimes down to the county or town level — is handling the situation in their own way, Barry Bloom, an immunologist at Harvard T.H. Chan School of Public Health, said January 28 in a call with journalists. Who is even eligible for the shots varies from place to place, causing confusion and frustration. Such a local response “is very difficult to coordinate, which I think is a real tragedy and a hindrance to knowing exactly where the vaccines are needed, exactly how many doses should go, which vaccines they have the facilities for,” Bloom said

The situation may change as the Biden administration begins implementing plans to help states fast-track vaccine rollout, including administering at least 100 million doses before April 30 (SN: 1/20/21).

There are also stark disparities among which regions of the world are getting vaccines. The great majority of vaccine doses — more than 39 million — have gone to the world’s richest 49 countries. So while vaccines are hard to come by in places like the United States, it’s even more difficult in countries with lower incomes. 

After getting a shot, do we need to continue to wear masks and social distance?

Yes, wearing a mask and keeping distance are still essential, even for individuals who have already gotten a shot.

The vaccines are very effective at preventing people from developing COVID-19 symptoms, but it’s unknown whether vaccinated people could still get infected without having symptoms and unknowingly spread the coronavirus to others (SN: 12/8/20). Not all vaccines stop both disease and transmission. Vaccinations for influenza, pertussis and polio, for example, can stop people from getting severely ill if infected, but those people could still be contagious.  

People who have been vaccinated should follow public health guidelines to protect those who have not yet gotten shots, at least until scientists know more about the vaccines and transmission. Also, Pfizer’s and Moderna’s vaccines aren’t 100 percent effective, meaning not everyone who gets vaccinated develops a robust immune response that protects against COVID-19. So, with transmission rates still high in many parts of the world, including the United States, and large swaths of the population still unvaccinated, it’s best to err on the side of caution.

The Johnson & Johnson vaccine reported lower efficacy than Pfizer’s and Moderna’s. Should I get it?

Here are some reasons why it’s worth getting the Johnson & Johnson vaccine if that’s the one available to you.

It was 85 percent effective at preventing people from dying of COVID-19. That’s still a really high level of protection. In clinical trials, vaccine efficacy measures how many fewer cases of disease happen in vaccinated people compared with in unvaccinated people.

“We would be celebrating a seasonal influenza vaccine with 60 percent efficacy,” Jay Butler, the CDC’s deputy director for infectious diseases said January 29 during a news conference sponsored by the Infectious Diseases Society of America. (Flu shots are typically around 40 to 60 percent effective.) “While it’s disappointing compared with the 95 percent efficacy from the Phase III clinical trials of the [Pfizer and Moderna] vaccines… it’s still not something that would make me want to not utilize or receive the vaccine myself,” Butler said. 

It’s also a single shot, so people don’t need a second vaccination to get full protection. Besides only needing to get jabbed once, that also means less of a logistical hassle to try and set up multiple appointments.

And if the FDA authorizes Johnson & Johnson’s vaccine for emergency use, that would make millions of additional doses available in the United States and help alleviate dose shortages. That could speed up vaccinations and get us back to normal faster.

I’m vaccinated. Can I spend time with other people?

Yes, but still with proper precautions for now.

Having highly effective vaccines on hand certainly changes the ways we might evaluate risk, Dean says. But since it’s still unknown what the vaccine might mean for transmission, vaccinated people should follow guidelines like masking up around people who haven’t yet gotten a shot and staying physically distanced. So, for instance, a vaccinated employee should still mask up at work if their colleagues and the people they might encounter aren’t vaccinated yet.

But if all members of a group have been fully vaccinated — and it’s been at least a week after the second dose to let the immune system mount optimal protection — there is some room to be more lenient.

“There are things I would be more willing to do once vaccinated,” Dean says. For her, that means spending time outside with a friend who also has been vaccinated. That equation may be different for others.  

Vaccination status is only one piece of the puzzle. It’s also important to consider how much transmission is happening in the community or how many people others in the group are in contact with, Dean says, since the vaccines aren’t 100 percent effective.   

And for now, it’s best to avoid travel, especially with emerging, more contagious variants, the CDC says. One that originated in the United Kingdom is on track to become the dominant strain in the United States in March (SN: 1/15/21). And the first two cases of a worrisome South Africa strain were detected in South Carolina on January 28. Neither person had traveled nor had connections with each other, suggesting that variant is already circulating in communities.

When will researchers figure out if COVID-19 vaccines can stop transmission?

It’s hard to say.

Some preliminary clinical trial data from Moderna hint that its vaccine might not only protect vaccinated people from developing symptoms, but also prevent infection in general (SN: 12/18/20). If people aren’t getting infected in the first place, then they won’t spread the virus to others. It’s still unclear if that’s the case, however, and clinical trials that could help figure that out are still ongoing, Dean says.

One way that researchers could figure out if vaccinated people are still getting infected but not showing symptoms is by monitoring their blood for immune responses against parts of the virus that aren’t in the vaccine. The primary target of a vaccine-induced immune response is the coronavirus’s spike protein, which helps the virus break into cells (SN: 4/28/20). But if people have antibodies against other parts of the virus, too, it’s a sign that they probably were infected by the real thing.    

Even if the vaccines don’t prevent infection, they might still reduce transmission. Vaccinated people who get infected with the coronavirus may have fewer symptoms or carry less virus in their bodies, for instance. So they might be both less infectious and only able to spread the virus for a shorter time. That would require specialized studies to determine, though.

“It’s pretty easy to see if the vaccine is preventing an infection, so if it’s doing a great job against that then we have our answer,” Dean says. But if a vaccine’s protection falls in-between — curbing transmission but not infection — that will take more time to confirm.    

What about these new coronavirus variants? Will vaccines protect people from them?

The vaccines appear to provide some protection. Recent studies have shown that antibodies circulating in the blood can still stop some viral variants from getting into lab-grown cells (SN: 1/27/21).

In the lab, antibodies still recognize a coronavirus variant called B.1.1.7 that was first identified in the United Kingdom. Another variant that emerged in South Africa, called 501Y.V2 or B.1.351, appears to pose a tougher challenge for current vaccines, evading some — but not all — antibodies.

Researchers are now getting hints at how that might play out in the real world. While Novavax’s vaccine had an efficacy of 85.6 percent against B.1.1.7 in a clinical trial conducted in the United Kingdom, efficacy dropped to 60 percent against B.1.351 in a South Africa clinical trial. Johnson & Johnson’s vaccine had 57 percent efficacy in South Africa, but did prevent people there from getting severely ill.  

The emergence of such variants makes it all the more crucial to bring infection levels down, says Stuart Ray, a virologist and infectious disease physician at Johns Hopkins University. More infections mean more chances for the virus to mutate even more and dodge our defenses.  Multiple vaccine makers — including Novavax, Pfizer and Moderna — are designing new vaccines based on the emerging versions of the coronavirus.

But for now, even with effective vaccines, public health measures like wearing masks, social distancing and avoiding crowds are still essential tools to help reduce infections and control the pandemic.

Is it OK to get one COVID-19 vaccine for your first shot and a different one for your second shot?

Maybe. Right now, public health officials say you should stick with the same kind of shot. But researchers are looking into how well mixing and matching different vaccines works.

And in fact, the idea to vaccinate people with two different vaccines isn’t new. For more than a decade, researchers have been exploring whether that tactic could help fight diseases like HIV or tuberculosis. And now researchers are testing the technique to fend off COVID-19. In fact, Russia’s COVID-19 vaccine, Sputnik V, uses this strategy. It’s a two shot-vaccine. Each shot contains genetic instructions to make a coronavirus protein for the immune system to recognize and attack. Those instructions have to get to human cells though. And they get there in what’s called a viral vector. 

Sputnik V uses two different adenoviruses, viruses that cause the common cold, as the vector. Those viruses are tweaked so they can’t replicate in the body and cause disease. But because that vehicle is a virus, people can develop or might have already had an immune response against it. That could stop the vector virus from delivering its payload to a cell, making the vaccine less effective. Giving people a different vaccine or a vaccine with a different viral vector to boost the immune response could help overcome the issue.

Other vaccine developers are considering mixing and matching COVID-19 shots too, including AstraZeneca, which uses a chimpanzee adenovirus-based viral vector in its vaccine. The company is testing a regimen that uses both its vaccine and Sputnik V.

Meanwhile, researchers in the United Kingdom launched a study February 4 to test whether mRNA vaccines like Moderna’s and Pfizer’s and adenovirus-based vaccines could be used together. That combo sparked a stronger immune response against the coronavirus in mice than animals given a single dose of either vaccine, according to preliminary results reported January 29 at bioRxiv.org. Mice vaccinated with a combination of both shots had more immune cells called T cells. These cells can provide protection from a virus even if it has evolved mutations to hide from immune proteins that stop the virus from infecting host cells. 

If we still have to wear masks and physically distance, what’s the benefit of getting the shot?

On a personal level, getting vaccinated make it less likely that you’ll get sick and require hospitalization.

Bigger picture, if fewer people are getting severely ill because they are getting vaccinated and because they continue to wear masks and physically distance, that’s fewer people in the overwhelmed health care systems that are already struggling to take care of severely sick COVID-19 patients.

And eventually, once enough people are vaccinated, hugs, travel and other rituals of normalcy will become less perilous. When is unclear, but every vaccination is a step closer.

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Staff writer Jonathan Lambert contributed to this story.