RELATED: If You Got This Vaccine, You May Never Need a Booster, New Study Says. Since the three vaccines approved for use in the U.S. are all relatively new, we’ve had to wait for data on their efficacy over time. As more time passes, however, researchers are able to get a better understanding of how well the vaccines work months and ultimately years after immunization. According to Johnson & Johnson’s recent statement, data shows that the “durability of the immune response [of the Johnson & Johnson vaccine] lasted through at least eight months, the length of time evaluated to date.” Data will continue to be collected beyond eight months to see if the vaccine remains protective for even longer. Significantly, research shows that the Johnson & Johnson vaccine actually became more protective over time. Mathai Mammen, PhD, Global Head of Janssen Research & Development, said in the statement that the “vaccine generates a strong neutralizing antibody response that does not wane; rather, we observe an improvement over time. In addition, we observe a persistent and particularly robust, durable cellular immune response.” RELATED: For more up-to-date information, sign up for our daily newsletter. And for those worried about the rapidly spreading Delta variant, Johnson & Johnson noted in its statement that research shows the vaccine “generated strong, persistent activity against the rapidly spreading Delta variant and other highly prevalent” variants. “We believe that our vaccine offers durable protection against COVID-19 and elicits neutralizing activity against the Delta variant,” Paul Stoffels, MD, Vice Chairman of the Executive Committee and Chief Scientific Officer at Johnson & Johnson, said in the statement. “This adds to the robust body of clinical data supporting our single-shot vaccine’s ability to protect against multiple variants of concern.” According to the statement, both of these studies were submitted to be printed in bioRxiv. While a handful of experts have suggested people who got the Johnson & Johnson vaccine consider getting a booster shot, others believe this would be an unnecessary precaution. During a July 1 White House press briefing, White House COVID adviser Anthony Fauci, MD, vouched for the effectiveness of the Johnson & Johnson vaccine. “With regard to the idea of boosting, there’s a lot of talk about that—but right now, I think we still need to remember that, in fact, the J&J vaccine is a highly effective vaccine that has been recommended very clearly and has received an emergency use authorization,” Fauci said. RELATED: This One Thing Lowers Antibodies After Vaccination—and 6 Million People Do It.