The Minnesota Daily emailed questions to Dr. Mark R. Schleiss, faculty member of the University’s Division of Pediatric Infectious Diseases and Immunology, who answered some of your questions and concerns about getting vaccinated.

Do you have a certain recommendation for which vaccine to get? How should Americans decide, if they have a choice, on which one is best for them?

My advice is to get the vaccine that you can get fastest! In terms of protection, I do not believe there are meaningful or practical differences in their ability to protect against COVID disease. We will see a short pause for the Johnson & Johnson vaccine in the days ahead, but I fully expect this vaccine to become available again very soon … The saddest, most poignant stories I read in the news are the accounts of people who acquired, and sometimes died of, COVID while they were hesitating in making a decision about vaccination.

What are the main reasons for halting the Johnson & Johnson vaccine distribution? Why might the U.S. decide to take this measure and what do you think would make them approve it again?

It is an appropriate and reasonable action to take. Now, having said that, it is urgently important to look at the data carefully and make sure we understand what is going on. A very small number of women (six to date) have developed blood clots after the [Johnson & Johnson] vaccine. To put it in perspective, this is out of over six million doses administered, so it is literally a one-in-a-million risk.

It is likely that we will see a recommendation to resume immunization, but with some cautionary information provided about the blood clot risk, in particular, information about how to manage these blood clots should they be identified by clinicians.

How long until we know the true long-term effects of the vaccine? So far, what are major concerns?

There have been millions of doses of vaccines administered globally for many months, and so far, there are no discernable long-term adverse side effects.

Now, with respect to short-term side effects, we need to continue to be mindful of these and counsel patients appropriately. Headache, low-grade fever, arm soreness and, less commonly, tiredness, headache, muscle pain, chills, and nausea can occur.

What is the difference between a vaccine’s efficacy rate and its effectiveness?

What it means for a vaccine to have “efficacy” is that the vaccine demonstrates a defined percentage of reduction of disease in a vaccinated group of people compared to an unvaccinated group.

The important point here is that a higher “efficacy number” does not mean that it is a “better vaccine.” This is a common misperception.

What it means for a vaccine to be “effective” is gauged by what epidemiologists refer to as “observational studies” monitoring disease in a community. Unlike an efficacy trial, it is a “real world” observation because people in their everyday lives are not randomly assigned to a treatment versus a placebo group. Monitoring the community for infection and disease is a big part of this. If a vaccine is effective, the cases are more likely to be the unvaccinated individuals.

Vaccines do not always need to have an exceptionally high effectiveness to save lives. With respect to the flu question, in a typical year the influenza vaccine is 40-60% effective but we know it saves thousands of lives every year.

One of the greatest frustrations physicians, epidemiologists and scientists have is when the general public looks at an effectiveness number of 40-60% and concludes that the annual flu vaccine is not worth getting. That decision — to refuse the annual influenza vaccine — typically results in lost lives, which is unfortunate.

What do you have to say for Americans that are still skeptical about getting vaccinated?

I think that adults certainly have the right to refuse vaccines. I cannot imagine a nation where they would be forced to be immunized. But, vaccine refusers must accept as a fundamental component of their vaccine refusal that this “right” does not extend to a right to put others at risk.

There are rumors of the Johnson & Johnson vaccine having effects on women’s fertility, can you explain the science behind the creation of this vaccine in comparison to Pfizer and Moderna?

There is no plausibility to this. It is best characterized as a prevarication [a lie], put forth in many cases not even by people but by weaponized communications arising on social media sites. We should not have to even say that these vaccines do not cause infertility — it is preposterous.

What is the likelihood of “vaccine travel passports” going to be once most Americans are vaccinated? Will these be required for travel?

In my professional opinion, I do not think we will see “travel passports” issued or enforced. I think it is just a logistical nightmare and will be hard to enforce … I think health care workers should have to provide proof of vaccination before seeing patients in the workplace … I think students will have to provide proof of vaccination before being allowed to go to school, of course following age-specific guidelines (college students now, earlier grade levels in the future).

What does it mean for a virus to mutate? How have we seen mutations affect COVID-19? How do we adapt vaccines to counter these variants?

I prefer the word “evolve” over “mutate.” “Mutate” has pejorative, nefarious connotations. … It is an RNA virus so it changes all the time! It is just a part of its nature. And yes, we see variants. I prefer to call them variants, not mutants.

What does it mean for a community to have herd immunity? How long do you think it will be before we reach it? What does that mean for those that are vaccinated and for those that are not?

I am not sure we will ever see herd immunity to COVID because it changes so rapidly. We do not see herd immunity to influenza, after all. I think we will need annual boosters for many years as the virus changes. Politicians who argue that we already have herd immunity do us a real disservice.

For those who have the vaccine, it means that they are doing what they can to protect their lives and the lives of their families, loved ones and communities. For those without the vaccine, it means that they are putting themselves and others at risk.

This interview has been edited for length, grammar and clarity.