Your COVID vaccine booster might be a patch or a pill. Or it might come with your flu shot.

While the Biden administration has been racing to maximize the number of Americans vaccinated against COVID-19, government researchers have also been working on what form the next generation of vaccines will take.

They may be combined with the seasonal flu vaccine, or could come in the form of pills or patches instead of shots. Scientists also envision vaccines that might shield against viruses beyond SARS-CoV-2 (the virus that causes COVID-19) that could avert future pandemics. And they're evaluating whether those who are fully vaccinated might need booster shots later this year. Additional shots could be virtually identical to the first doses, given as a safeguard against the possibility of waning immunity or tweaked to defend against mutant strains that are raising concerns.