Transcript for Vaccine Watch: How far away are COVID-19 booster shots?
Bob Johnson and Johnson's vaccine is temporarily paused Madeira and fine is there are now looking ahead in the fight against the pandemic with both companies working on potential booster shots to target company's nineteen variance to could we soon be taking with Kobe booster vaccine in the future the same way we have an annual flu shot. Our Bob Woodruff takes a look in this week's vaccine much. The next stage of the battle against cove in nineteen is already under way Pfizer in the dharma taking their first steps sometime around. In January. The Sudanese hate being. Seen. Becky Timmons was part of Pfizer's stage one vaccine trials last year and once it was authorized her friends her family. All began to receive the vaccine to. It was better than Christmas and out about her holiday I had gotten the scene and they really didn't know that one and Aaron C anyone else is receiving. And despite some mild symptoms she did not hesitate to sign up for the booster trials. Experts need pretty clearly. Out of money producer I pretty much new mix. She is one of dozens of Americans testing booster shots for Pfizer in the journal. At Emory university and the University of Rochester and or trials are being held. I had no problems at all with other study and I thought it would be helpful as far as the advancement of the solutions she is decoded. Pandemic so last happy to contribute. With 30% of US adults now fully vaccinated. Scientists are already looking ahead. Trying to develop a shot that will protect against new versions of the virus that might emerge in the future. Somebody didn't it was a shock is needed that's exactly what I understand that it's. Some some people. Well the current vaccines have been highly effective one variant first identified in South Africa was proven slightly more resilient. Scientists have made this their target. This is not a bomb insane they doesn't think it must be. Viruses are always a ball but the more they spread the more potential for change. These booster shots are getting us prepared for new versions of the virus capable of outsmarting existing vaccines. We didn't know that with some respiratory viruses like influenza. We know that we need to get a shot every year and it least present moments coated nineteen appears to be eating somewhat similar link. Madonna and Pfizer are both testing different strategies some volunteers will get a third dose of the original vaccine. While others will get a shot that includes a tweet vaccine. Specifically designed to target the south African variant. This week the journal published encouraging results from mice studies. Well we observed an experiment was that reminds you received a third jettison MR name 1273. Post vaccination antibody in animals that were higher than those green booster gas. Now they're scientists feel confident they are on the right track I think I was just this big plus. Veteran TW working on Barrett and CEO Brennan it's just to be how this. Researchers say booster shots could be ready soon. The studies. I've been done you have to wait a period of time for people telling me and responds. And then. Please we consider you know whether go to the FT eight I do not change it would acquire. He's very large efficacy trials these are considered minor modifications are not seen. But still many unanswered questions. How quickly will the virus changed and how often might we all need to take these booster shots. And why I'll. Just boosting. Your. Chain siege are these new variants. With the near 100% rate of preventing hospitalizations. And deaths MR NA vaccines such as Pfizer in the dirt as vaccine. Do have one key advantage. They can be updated quickly and easily we are well. Looking to see if we can create an urban I've seen where we can demonstrate an if you changed as she once you can and create the antibody responses. And any allow us to move to a situation in the future where emerging. Stars Kirby she sequences. Can be swapped out of the vaccines who will lay out. Nearly ministers at sacred to the wounds. For Becky the benefits have outweighed her miles symptoms after getting vaccinated. The gal and I am able to travel needs your and those. Numbers that would enable this is what we're really not so I was animated you. As scientists are hopeful that these booster shots. Will protect us in the years to come. Soon because the original Sheen out worked better than anybody's expectations. I'm Bob Woodruff tracking the vaccine.
This transcript has been automatically generated and may not be 100% accurate.