May 22, 2022

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NEJM: Fourth mRNA vaccine significantly improves prevention of Omicron in the elderly

NEJM: Fourth mRNA vaccine significantly improves prevention of Omicron in the elderly



 

NEJM: Fourth mRNA vaccine significantly improves prevention of Omicron in the elderly

On March 29, 2022, the U.S. Food and Drug Administration (FDA) authorized the use of Pfizer BioNTech or Moderna for the elderly, immunocompromised, and those with other serious illnesses or at increased risk of hospitalization and death The second booster shot of the COVID-19 vaccine – that is, the fourth dose of the COVID-19 vaccine.


This is not the first time a decision has been made to use a fourth dose of the vaccine. Previously, the FDA had authorized a single booster shot for certain immunocompromised people after completing three doses of the vaccine.

 


The fourth shot of the COVID-19 vaccine is here, and the effectiveness exceeds expectations ?

At the end of March this year, after the US FDA approved the authorization of the fourth booster injection, together with the US Centers for Disease Control and Prevention (CDC), people aged 50 and over will be widely vaccinated again. The reason why the two authoritative organizations made this decision is supported by clinical trial data.


On December 21, 2021, Israel is striving to be the global “vaccination pioneer”, opening the fourth dose of the COVID-19 vaccine to people over 60 years old and medical personnel. All medical personnel participating in the trial completed the test before August 20, 2021. The third injection.


The data showed that in the week after the fourth injection, the antibodies in the medical staff increased five-fold.


Since then, on January 4, 2022, Israel has launched the fourth COVID-19 vaccination program for high-risk groups, including the elderly over 60 years old and immunocompromised people. The vaccine injected is the Pfizer BN162b2 vaccine.

On April 13 , Israeli researchers published a paper titled: Fourth Dose of BNT162b2 mRNA Covid-19 Vaccine in a Nationwide Setting in the New England Journal of Medicine (NEJM).

In the observation of the effect of the “fourth injection” of the COVID-19 vaccine in the elderly, it was found that during the epidemic period of Omicron, those who received the fourth dose of the COVID-19 vaccine had significantly stronger resistance to the virus than their peers who had only received three injections of the vaccine. .

 

NEJM: Fourth mRNA vaccine significantly improves prevention of Omicron in the elderly

 

The data for the study is based on 258,994 eligible vaccinators who participated in the study during the period of the Omicron virus outbreak in Israel, from January 3 to February 18. The two groups of people who received three injections were compared, and the average age of the participants in both groups was 72 years old.

 

NEJM: Fourth mRNA vaccine significantly improves prevention of Omicron in the elderly
Personnel selection process for the fourth dose group and the matched control group

 

 

The study found that people who have completed the fourth and third injections have very significant differences in various risk levels. The following is a specific table of effectiveness differences between the fourth and third injections.

 

The main conclusions drawn by the paper are as follows:

During the 7-30 day period after vaccination:

1. The positive rate of the COVID-19 has been reduced by 45%;

2. The proportion of symptomatic infections decreased by 55%;

3. 68% drop in COVID-19-related hospitalizations;

4. Severe illness rate dropped by 62%;

5. The death rate related to Covid-19 has dropped by 74%.

 



During the 14-30 day period after vaccination:

1. The positive rate of the COVID-19 decreased by 52%;

2. The proportion of symptomatic infections decreased by 61%;

3. The probability of COVID-19-related hospitalizations has dropped by 72%;

4. Severe illness rate dropped by 64%;

5. The death rate related to Covid-19 has dropped by 76%.

 


NEJM: Fourth mRNA vaccine significantly improves prevention of Omicron in the elderlyFourth shot is more effective than third shot, study shows



From the above conclusions, we can be sure that the elderly who receive the fourth injection will receive more and more effective protection.

The results of this trial have provided us with a very good sample for us to learn from foreign experience and to observe immunization policies around the world.

 


Opinions Differ: Is the Fourth shot Necessary?

Although the data from the studies above support the idea that a fourth dose of the Pfizer mRNA vaccine is more effective than just three doses, not all studies have come to the same conclusion.

On March 17 this year, another study from the Sheba Medical Center in Israel showed that the fourth dose of the vaccine had little effect against the new coronavirus.

Of about 600 trial participants, 270 were vaccinated with the fourth dose.

Those who received the Pfizer/Moderna vaccine, their antibody levels and neutralizing antibody levels were not much better than the levels measured one month after their third dose, which was basically the same.


That said, in this Israeli trial, the fourth shot had little special effect.

 

NEJM: Fourth mRNA vaccine significantly improves prevention of Omicron in the elderlySouth Koreans are getting the fourth shot

 

 

So far, only a handful of countries have touched the fourth shot.

In addition to the latest authorization by the FDA in Israel and the United States for the third dose of the COVID-19 vaccine for people over 50 years old, Singapore launched the “fourth dose” vaccination layout at the beginning of this year; South Korea has also recently started the fourth dose of the COVID-19 vaccine for people over 60 years old.

 

As of April 26, the reservation rate for the fourth dose of the COVID-19 vaccine for people over 60 was 19%.



In the context of global vaccination, most countries are still on the sidelines.

 

 


Why do we need a new vaccine, the fourth shot?

Previous studies have found that the immune effect of the current vaccine against Omicron has declined. Therefore, if the existing vaccine is continued to be used as the fourth shot, the effect may not be very good.

An article published on CNBC on April 6, Scientists divided on need for 4th Covid shot after FDA quietly approved another round of boosters, stated that some scientists believe that over time, Pfizer and Moderna vaccines The amount of protection against infection has dropped considerably, especially in the context of the Omicron epidemic.

Omicron mutates and enhances the ability to cause breakthrough infections and mild disease.

This shows that as the Omicron virus continues to mutate, its escape from the vaccine also increases, and it can more and more easily escape the “control” of the vaccine. But don’t worry too much, the existing vaccines can still effectively reduce severe illness and mortality, and provide us with substantial protection.

Based on the premise of the increased escape of the Omicron variant, domestic vaccines are exploring a more targeted new way.

 

 

 

 

 

 

 

References :
https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-authorizes-second-booster-dose-two-covid-19-vaccines-older-and
https://www.nejm.org/doi/pdf/10.1056/NEJMoa2201688?articleTools=true
https://www.cnbc.com/2022/04/06/scientists-divided-on-need-for-4th-covid-shot-after-fda-quietly-approved-another-round-of-boosters. html
NEJM: Fourth mRNA vaccine significantly improves prevention of Omicron in the elderly

(source:internet, reference only)


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