How long does the new crown vaccine "work"?

▎The content team editor of WuXi AppTec.
With the widespread advancement of COVID-19 vaccination, how long it takes to “work” after vaccination is a common concern.

Is it just like the BCG vaccine once in a lifetime, or does it need to be vaccinated every year like the flu vaccine? Due to the limited time of preliminary clinical trials, many long-term data are still accumulating.

However, a new study published in the New England Journal of Medicine (NEJM) initially brought good news: Long-term follow-up of Moderna's new crown vaccine vaccinators showed that the immunity brought by the vaccine was maintained for at least 6 months.
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Screenshot source: The New England Journal of Medicine.
This study, led by scholars from the National Institute of Allergy and Infectious Diseases (NIAID), analyzed the serum antibody data of 33 subjects participating in a key clinical trial of Moderna's new crown vaccine.
These subjects have been vaccinated with the second dose (100 μg) for more than 180 days, and the age span is between 18-71 years.

In general, on the 209th day of vaccination, the antibody activity in subjects of all age groups remained at a high level.

And this result has been verified in three different types of tests.

However, as we age, antibody levels do decrease.

The data shows that the geometric mean titer (GMT) of the binding antibody against the new coronavirus S protein is 92,451 in subjects aged 18-55, 62,424 in subjects aged 56-70, and subjects ≥ 71 years old.
It is 49373.

In the pseudovirus neutralization test, the antibodies in almost all subjects have detectable activity.
The 50% inhibitory dilution (ID50) GMT of the antibodies in subjects of different age groups are 80, 57, and 59, respectively.

In the more sensitive live virus attenuation and neutralization test, the antibodies in all subjects still have detectable activity.

The GMT of antibody ID50 of subjects in different age groups were 406, 171, and 131, respectively.

Compared with the 18-55-year-old population, the neutralizing activity of antibodies in the two groups of elderly population is lower.

▲In the S protein binding test (A), pseudovirus neutralization test (B), and live virus neutralization test (C), the vaccinators have higher antibody activity in the body within half a year after the second dose of vaccination (day 29) High (Image source: Reference [1]) The model estimate shows that if the antibody decay rate is assumed to be stable over time (exponential decay model), the estimated half-life of the bound antibody is 52 days; if the decay rate is assumed Decrease over time (power-law models), and the estimated half-life of the bound antibody is 109 days.

Under the two models, the half-lives of neutralizing antibodies against pseudoviruses were estimated to be 69 days and 173 days, and the half-lives of neutralizing antibodies against live viruses were estimated to be 68 days and 202 days, respectively.

After calibration, the results of exponential decay and power law models are more suitable for binding antibodies and neutralizing antibodies, respectively.

These results are consistent with the results of antibody studies in patients who have recovered from the new crown 8 months after the onset of disease.

The research team pointed out that these data show the persistence of antibodies after vaccination and support the role of the vaccine in solving the new crown pandemic.

At present, the NIAID research team is continuing to monitor the longer-term immune response of vaccinators, and further determine whether the role of strengthening immunity, such as against mutant viruses, can help extend the duration and activity of antibodies.

What is reassuring is that this result is similar to the latest BNT162b2 vaccine data released by Pfizer/BioNTech recently.

In the Phase 3 clinical trial, data as of March 13, 2021 showed that BNT162b2 has a 91.
3% protection against COVID-19, and this protection lasts for at least 6 months.

The positive news of the two mRNA vaccines undoubtedly provides important support for the lasting protection of the vaccine.

Dr.
Amesh Adalja, a virology expert at Johns Hopkins University, commented that the actual duration of immunity after vaccination with the new crown vaccine may be longer than the 6 months currently reported by researchers.

"With the advancement of research on antibodies and other related factors of immunity after the new crown vaccination, it is expected that we will observe immunity for a long time.

" New crown research related reading JAMA published 3.
64 million data: vaccination of mRNA new crown vaccine , How common are local and systemic reactions? Are there many allergic reactions to the mRNA new crown vaccine? JAMA publishes safety data on vaccination for over 60,000 people.
3 NEJM articles on the same day: Post-vaccination infection is a case.
The new crown vaccine is generally effective in reducing 92% of new crown infections and 94% of cases in medical staff.
NEJM published the data of 600,000 people vaccinated with Pfizer/BioNTech vaccine in Israel.
Source: 123RF reference materials[1] Nicole Doria-Rose, et al.
, (2021).
Antibody Persistence through 6 Months after the Second Dose of mRNA-1273 Vaccine for Covid-19.
The N Engl J Med, DOI: 10.
1056/NEJMc2103916[2] Moderna COVID vaccine offers protection for at least 6 months, study finds.
Retrieved April 7, 2021, from https://medicalxpress.
com/news/2021-04-moderna-covid-vaccine-months.
html Note: This article aims to introduce medical and health research progress , Is not a treatment plan recommendation.

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