Thirteen months ago, Ebenezer Tumban was an associate professor of molecular virology and vaccinology at Michigan Technological University and told us about how COVID-19’s cellular envelope was special and made it more dangerous.

At the time, the COVID-19 vaccines were still in early development.

Now we have three vaccines being distributed in the United States, and Tumban has moved to Texas to take a job in Texas Tech University’s School of Veterinary Medicine. He still agreed to a follow-up interview about the vaccines, their effectiveness, and their side effects.

Vaccines are the way out of the pandemic

“This virus mutates every day, as we speak,” Tumban said.

Not all viruses mutate very quickly, but because COVID-19 does, the pandemic is something of a race between how quickly humans get vaccinated, and how quickly COVID-19 can mutate.

Several mutated varieties of COVID-19 have already been discovered, and more are likely. Each new variant is potentially more dangerous.

Tumban explains that the spike protein on the outside of coronavirus cells is like a key, and each mutation on the spike protein is modifying the key to fit a new door, unlocking new ways to infect more cells faster. With each new door it opens, the virus has more options for hosts, and more “space” to continue its development.

Vaccines add an additional defense to your immune system, kind of boarding up the door, and have so far proven effective against some of the mutated strains, too. However, more time among unvaccinated populations gives the virus opportunities to overcome these, too.

Tumban stresses that if everyone is vaccinated and immunized within the same timeframe, then the immune system can destroy the virus and eliminate the potential for dangerous variants in the future. Unvaccinated populations provide opportunity for COVID-19 to persist and continue mutating. As time goes on and the virus persists, new variants are likely to get more and more dangerous.

“We can win the race, if there’s cooperation from people,” Tumban said.

Protection from the virus is not 100% with the vaccine. This is why ‘herd immunity’ is so important. The people who surround a person who has an immune system that cannot mount a good protective response to the vaccine can protect them by being vaccinated themselves. As each person in a community becomes more difficult for COVID-19 to infect, the chance of widespread infection decreases.

Studies continue to fill in the unknowns

The U.S. FDA has approved three vaccines for emergency use, but they are not fully licensed, largely because the studies of them are still comparatively short. One major unknown is how long the protection from these vaccines will last.

“They see that the antibody levels are still good after six months,” Tumban said. “The studies are still ongoing.”

Tumban said one possibility is that another booster shot might be necessary, but it’s also possible the vaccine’s protection is long-lasting.

“You need a lot of studies and more people,” he said.

Some recipients of the Pfizer vaccine have had severe allergic reactions, and a few recipients of the Johnson and Johnson vaccine have experienced dangerous blood clots. The FDA has issued new advisories to cover these rare situations, and the studies into them are ongoing, too. Tumban said there are a lot of potential reasons for these rare reactions because people are different from each other.

Tumban said that because of the basic differences between every person, each person may react differently to the vaccine.

Previous virus exposures, general health levels, age, stress, and more can play a part in the immune system’s response to a vaccine. The symptoms many people are showing after the second dose of Pfizer or Moderna vaccines—fatigue, fever, discomfort, etc—are signs that the immune system has detected something foreign and is trying to fight it, creating the antibodies needed to fight COVID-19.

Some people, disturbed by these symptoms, have elected not to get the 2nd dose. But Tumban thinks that’s a big problem.

“We’re not even sure how long the immune response with two doses is going to last, let alone one dose,” he said.

Studies have shown that a single dose gives a person some of the protection of two doses, but may not be effective against variants. Tumban said the first shot is like a primer, getting the immune system ready to build antibodies, but with many people, not many antibodies are actually made until the second dose. As studies continue, Tumban said it’s possible that a third dose might even be required.

Tumban is fully vaccinated and had a fever and other symptoms with his 2nd dose. Thinking about it, he decided it was better to be temporarily uncomfortable than to risk going to the emergency room and potentially suffocating from lack of oxygen like people are experiencing in India.

Tumban thinks testing needs to happen on a more global scale, too.

“I know you’re going to have people from different countries that have different genetic backgrounds,” he said. “They may react differently.”

He hopes Americans take heed of the lessons of the COVID-19 pandemic.

“I think this is like a wake-up call for people to reflect on what’s happening and that things like this can happen in any country,” Tumban said.

Editor’s note: This story’s wording has been adjusted in five areas to be more precise. No major points of fact were changed.