Post-vaccination questions

As Europe and Asia stumble in vaccinating their citizens, America has leaped ahead. The United States in mid-April was averaging more than 3 million doses per day: President Biden had promised 100 million vaccines in 100 days, but the second hundred million shots had been distributed by day 92.

Yet lingering questions about the vaccine threaten to slow that progress just as they become available to all comers. Below I answer some common questions regarding the vaccines available in the United States.

Do the vaccines work? The vaccines used in the United States work very well. Moderna and Pfizer-BioNTech vaccines provide 80 percent protection two weeks after the first shot. After the second shot, protection increases: A large U.S. Centers for Disease Control and Prevention (CDC) study of vaccinated front-line workers found the two mRNA vaccines to be 90 percent effective in preventing any infection. An Israeli study showed the Pfizer jab to be 97 percent effective “in preventing symptomatic disease, severe disease, and death.” Researchers found the Johnson & Johnson vaccine 72 percent effective in preventing moderate to severe COVID-19.

If they work, why do some vaccinated people still get sick? You may have seen reports about people getting COVID-19 even after receiving the vaccine. For instance, in January, Iona College basketball coach Rick Pitino tested positive for COVID-19 “days after he received the first of two doses.” However, that was too early for the vaccine to have helped him. Like all vaccines, the COVID-19 jabs take time to work—about two weeks—as the immune system needs to learn what the vaccine is teaching it.

As of April 26, some 9,200 Americans had contracted COVID-19 after full vaccination. That number sounds large until one considers how many Americans had been fully vaccinated: 29 percent of the country, or 95 million people, at the time of the report.

How does the coronavirus affect vaccinated people differently than nonvaccinated people? Even in cases where the vaccines don’t fully stem infections, they can prevent suffering—and death—as the vaccines give the immune system a head start against the virus. Of those 9,200 “breakthrough” cases, 9 percent were hospitalized and only 1 percent died. This is an improvement as nearly half of the infections were reported in people aged 60 and up, the highest-risk group. Without vaccinations, the fatality rate in those over 80 years old was 8 percent.

Cases of COVID-19 contraction after vaccines are not only likely to be less severe but also less contagious than normal cases. The amount of virus found in nose and throat swabs in a large Israeli study was far smaller among patients who had been vaccinated. Remember Rt, the “effective reproductive number” discussed early in the pandemic, where an Rt of 1.0 means that each sick person infects an average of one other person? Vaccines push the Rt down in two ways: First, it’s very hard for vaccinated people to get COVID-19, and second, they appear to be much less contagious when they do.

If I’m vaccinated, can I have a cookout with nonvaccinated friends and family? Given what we know by this point, it’s low-risk for fully vaccinated people to spend time around nonvaccinated friends or family. If you’re organizing a group of nonvaccinated people who don’t normally have contact with each other, a cookout (or other outdoor activity) is a great way to limit their risk of infecting each other compared with meeting indoors.

If I’m vaccinated, should I still wear a mask? The CDC announced in April that fully vaccinated people should continue to wear masks in indoor public spaces or crowds. However, they do not need a mask when outdoors or indoors with fully vaccinated people or with unvaccinated people from one other household.

Personally, I’ve set my P100 mask aside but haven’t stopped wearing masks entirely yet. Not because I’m still at meaningful risk, but because I want to encourage patience among those who haven’t had their shots yet. Apart from that, life is resuming all around me, and inside my own household too: Having had our vaccines, we have cut both our own risk and the risk of those around us dramatically. Once a given person is fully vaccinated, the “new normal” looks more and more like the old normal.

—Do you have a question for Dr. Charles Horton? If so, please send your name and question to ­editor@wng.org