How long does COVID-19 vaccine immunity last?
Study shows that immunity declines over time, and booster doses are essential in maintaining vaccine effectiveness.
In a world where the COVID-19 pandemic has wreaked havoc over the last 3 years, vaccines have been the most critical tool in the fight against the virus. However, new research from Italy shows that vaccine-induced immunity declines quite rapidly over time.
According to a study published on May 3 in JAMA Network Open, a team of scientists from Italy analyzed 40 studies documenting people’s vaccination status and subsequent COVID-19 infections, confirmed by lab tests. The studies included data from both the Delta and Omicron surges.
Overall, the researchers found that one month after people received two doses of either the mRNA vaccine (from Moderna or Pfizer-BioNTech), the vaccine from AstraZeneca, or the shot from Sinovac, the vaccine effectiveness was 53% in protecting against symptoms of COVID-19.
However, after six months, the overall effectiveness of the vaccines dropped to 14%, indicating a decline in vaccine-induced immunity over time.
Furthermore, the study found that the Omicron variant has a more prominent and quicker waning of protection compared to the Delta variant. At six months after the last dose administration, the vaccine effectiveness against both laboratory-confirmed Omicron infection and symptomatic disease was less than 20%.
The study suggests that booster doses restore vaccine effectiveness to levels comparable to those acquired soon after the administration of the primary cycle. However, nine months after the booster administration, vaccine effectiveness against Omicron was lower than 30% against laboratory-confirmed infection and symptomatic disease.
The research team also estimated the half-life of vaccine effectiveness against symptomatic infection to be 87 days (67–129 days) for Omicron, compared with 316 days (240–470 days) for Delta. Similar waning rates of vaccine effectiveness were found for different age segments of the population.
These findings suggest that the effectiveness of COVID-19 vaccines against Omicron rapidly wanes over time. The study’s lead author, Francesco Menegale, said, “Estimates of the rate of waning of vaccine effectiveness against COVID-19 are key to assess population levels of protection and future needs for booster doses to face the resurgence of epidemic waves.”
As the world continues to fight the pandemic, this study underscores the importance of getting vaccinated and getting booster shots to maintain vaccine-induced immunity against COVID-19. The results can also inform the design of appropriate targets and timing for future vaccination programs.
The study’s findings could trigger strong emotions in people who may have been hesitant to get vaccinated. Some may feel justified in their decision to not get vaccinated if vaccine-induced immunity wanes over time.
Others may feel vindicated that booster doses are essential in maintaining vaccine effectiveness. It is crucial to acknowledge these emotions and focus on educating people on the importance of getting vaccinated and getting booster doses.
In conclusion, this study shows that COVID-19 vaccine-induced immunity declines over time, and booster doses are essential in maintaining vaccine effectiveness.
It is crucial to educate people about the importance of getting vaccinated and getting booster doses to protect against COVID-19. The fight against the pandemic continues, and we must remain vigilant in our efforts to stop the spread of the virus.
Let me know what you think in the comments below.
Recardie Murray is a reporter and blog writer for NewsBreak.ai
