A groundbreaking Centers for Disease Control and Prevention (CDC) report has unveiled the staggering extent of COVID immunity among Americans. Published on June 2 in Morbidity and Mortality Weekly Report (MMWR), the study analyzed data from June to September 2022, showcasing that about 96% of Americans aged 16 and above possess some level of immunity against the virus.
Within this vast majority, approximately 26% acquired immunity through COVID vaccination, while another 22% gained immunity solely from a prior infection. However, an impressive 48% achieved hybrid immunity, resulting from both vaccination and a past infection, bolstering their defenses against the virus. Commander Jefferson Jones, MD, MPH, USPHS, the report’s author and medical officer at the CDC’s Coronavirus and Other Respiratory Viruses Division, expressed enthusiasm, stating, “It is good news that, through vaccination and then as we progressed through the pandemic, the vast majority of people have some sort of immunity. This likely has contributed to the decreasing level of hospitalizations and severe disease that we’ve seen.”
Notably, the report also shed light on the effectiveness of vaccination programs throughout the pandemic. It revealed that individuals aged 65 and above exhibited the lowest rate of hybrid immunity and similarly low levels of infection-related immunity, indicating the success of public health measures aimed at preventing infections within this age group.
Experts weighed in on the implications of high COVID immunity and advised on protective measures. Dr. Jones explained the methodology used by the CDC to calculate national immunity, involving the examination of blood donations since July 2020. The analysis considered antibody tests and self-reported vaccine histories of a cohort comprising over 70,000 blood donors. Based on these data, an astounding 96.4% immunity rate was estimated among Americans. Dr. Jones noted that the percentage has likely increased since the data collection period, surpassing 96%, due to new infections and vaccinations.
Dr. Jeffrey Klausner, an infectious disease expert from the University of Southern California, acknowledged the growing number of protected individuals, emphasizing the reduction in hospitalizations and severe disease. The report also highlighted that nearly 86% of the unvaccinated population had acquired infection-induced immunity compared to 64% of vaccinated individuals. Unvaccinated individuals were more susceptible to new COVID infections.
Understanding the different types of immunity and their origins is essential. Hybrid immunity, resulting from a combination of vaccination and a previous infection, is considered the strongest form. This type of immunity was found to be the most prevalent among the population. However, antibodies acquired solely through a prior infection or vaccination still offer protection, accounting for 22% and 26% of the population, respectively. While both forms of immunity are protective, medical professionals generally recommend vaccine-induced immunity due to its safer nature. Dr. Jones highlighted the risks associated with infection, such as transmission to others, severe disease, and even death.
Nevertheless, it is crucial to note that possessing antibodies does not guarantee complete protection against COVID. Dr. Jones clarified that once infected, antibodies could be detected for at least a year, potentially longer. However, the presence of antibodies does not render a person impervious to infection or severe illness.
Quantifying the level of COVID protection in the United States presents challenges due to the varying degrees of immunity from person to person. Immunity, regardless of its origin, diminishes over time. Factors such as the number of infections and vaccinations, the time since infection or vaccination, and the matching of immunity with circulating viral strains affect the extent of protection. Dr. Jones stressed that the level of highly protected individuals is contingent on transmission rates and the population’s adherence to vaccine schedules.
The CDC report strengthens our understanding of COVID moving forward. While the strength of immunity may vary, the presence of antibodies indicates a reduced likelihood of severe illness among almost all individuals. Dr. Klausner stated, “The overwhelming amount of immunity in the population tells us we need to be much less concerned about serious disease and overwhelming hospitals.” However, assessing the strength of individual immunity poses challenges.
Currently, over-the-counter antibody tests are not available. Testing for antibodies can be done at local clinics or with the assistance of infectious disease experts to obtain more comprehensive information. To ensure robust immunity, staying up to date on COVID vaccines is crucial, as recommended by experts. Individuals aged six and above are considered up to date once they receive a single dose of the updated bivalent booster, with additional doses recommended for those over 65 or with compromised immune systems. However, only 17% of the U.S. population has met this criterion thus far.
Dr. Klausner encouraged individuals to receive their regular flu shot alongside a yearly COVID shot to boost and maintain their antibodies. While universal COVID shots protecting against all variants may be a possibility in the future, current vaccines will require periodic updates to safeguard against the prevalent strains. Dr. Klausner assured that scientists would continue updating COVID shots, likely on an annual basis, to ensure public safety.
In summary, staying up to date on vaccination remains the safest way to protect against severe illness, according to Dr. Jones. The report’s findings offer optimism as a vast majority of Americans possess COVID immunity, contributing to the overall decline in hospitalizations and severe cases. However, monitoring and adherence to vaccination schedules are essential to maintaining this progress and minimizing disruptions caused by the virus.