For older adults or immunocompromised people who need priority protection, the 4th dose is important
Written by | Yan Xiaoliu
Source | "Medical Community" public account
Recently, the mRNA new crown vaccine has also made new progress in the United States.
The U.S. Food and Drug Administration (FDA) statement said that the relevant vaccine is authorized to be given a second dose of booster vaccination in a specific population. In other words, some people are going to get the 4th shot.
This is another country that has started the 4th stitch after Israel, the United Kingdom, Germany, France and Sweden.
In February 2021, at a vaccination site in New Hampshire, USA, two injection bottles of the mRNA COVID-19 vaccine. /AP
Who is going to get 4 injections?
According to the FDA statement, all people 50 years of age and older are authorized to receive the 4th injection. Available vaccines include the Pfizer/Byntec mRNA vaccine "Comirnaty" and the mRNA covid-19 vaccine "Spikevax" developed by Modena.
In addition, people aged 18 years and older who are immunocompromised or have other specific health problems, including chemotherapy, organ and stem cell transplants, and HIV infection, may receive "Spikevax" as a second booster.
Those who meet the same criteria and are 12 years of age and older can be vaccinated with "Comirnaty" as a 2nd dose of booster injection.
All people who want to receive the second booster dose should be at least 4 months apart from the first booster dose.
It should be pointed out that according to the FDA vaccination instructions, if the immunocompromised people receive the mRNA new crown vaccine, the basic immunization dose is 3 injections. Therefore, the second dose is strengthened to be the fifth dose.
According to the Wall Street Journal, the above authorization may only be a short-term response. The FDA's Vaccine Advisory Committee will meet April 6 to discuss this fall's enhanced vaccination schedule. At that time, the 4th needle may cover all people.
Is the 4th stitch really needed?
Hospitalizations and mortality from COVID-19 appear to be decreasing. According to the World Health Organization, in the seven days as of March 22, there were more than 12 million new confirmed cases worldwide, and more than 33,000 new deaths in the same period, a 23% decrease from the previous death rate.
However, over time, the effect of the new crown vaccine on the elderly and immunocompromised people has also weakened. The U.S. Centers for Disease Control and Prevention published a study in February showing that the effectiveness of preventing hospitalizations declined from 91 percent to 78 percent after four months of 3rd injection.
"According to the latest data, the mRNA vaccine may help improve the level of protection as a second dose of booster." Dr. Peter Marks, director of the FDA's Center for Biologics Evaluation and Research, said.
CNBC reported that the evidence for the 4th needle authorized by the FDA came mainly from real-world research in Israel.
Recently, Clalit, the country's largest health service agency, published a study saying that for the elderly or immunocompromised/impaired people who need key protection, the fourth dose is important.
The study followed 560,000 people aged 60 to 100. The median age of respondents was 73 years, with 53% of women.
The results show:
Compared with people who received 3 doses of the vaccine, the 4th dose reduced the DEATH RATE OF COVID-19 by 78%;
Of the 234,868 people who had 3 injections, 232 died of COVID-19;
Of the 328,597 people who had 4 injections, 92 died of COVID-19.
The study has not been peer-reviewed. The Sapier College team, which led the study, said that because the variant strain Omiljung is more contagious, the fourth dose may not be significant in preventing infection, but it is effective in preventing severe illness and death.
Another single-centre study in Israel showed that in people aged 18 years and older who had completed basic immunization and received the first booster dose, the neutralizing antibodies against Omilon increased by 8-fold and 10-fold, respectively, after receiving the 2nd booster injection, 1 week and 2 weeks. In addition, the 4th injection tracking of 700,000 people showed that no new safety issues were found.
Israel was the first country in the world to receive the 3rd and 4th shots.
On 22 December 2021, the Expert Advisory Group of the Israeli Ministry of Health recommended that people aged 60 years and over and medical personnel receive the 4th injection for more than 4 months before the 3rd injection.
The country's health ministry said the decision was based on two considerations. The first is epidemiological studies showing that people over the age of 60 triple their risk of infection after 4 months of vaccination. The second was the person who received the 4th injection first, and it was found that the antibody level increased by 4 times, but there was no significant adverse reaction.
On March 17, Israel's Sheba Medical Center released the findings that a 4th dose of vaccine could help immunosuppressed people and the elderly. But the effect is not obvious for healthy young people, and many people are still infected, but either asymptomatic or mild.
The New England Journal of Medicine notes that this is why many countries prioritize the 4th injection for the elderly, who can reap the greatest "benefits."
Who else is going to get the 4th shot?
More countries are about to start the 4th needle program.
The Ministry of Health, Labor and Welfare of Japan held a vaccine sub-committee to decide to implement the fourth dose in May for everyone who has completed 3 doses for 6 months.
On 4 April, Australia also started the fourth injection. This is known as the "Winter Booster Needle" and will be launched in conjunction with this year's flu vaccination program.
"By April 1, about 160,000 people over the age of 65 had received the first dose of the booster injection, four months later. Early evidence suggests that the effectiveness of COVID-19 vaccines, including booster shots, is gradually diminishing. After 3-4 months of vaccination, the protection against hospitalization will drop to 75%-80%. "The call for the second dose of intensive injection is focused on protecting vulnerable groups from severe illness." Explained by the Australian Technical Advisory Group on Immunization (ATAGI).
ACCORDING TOAGI, the "Winter Strengthening Needle" will use a sequential strengthening method. Regardless of which vaccine is given in the first dose, the public can choose any approved vaccine as the fourth dose according to their own situation.
At present, there are 4 COVID-19 vaccines approved for use in Australia. In addition to the two mRNA COVID-19 vaccines mentioned above (Pfizer/Bynteco, Modena), there are also adenovirus vector vaccines (AstraZeneca) and recombinant protein vaccines (NovaX).
ATAGI recommends that the 4th dose be given 4 months after the 3rd dose. If a breakthrough infection occurs after the 3rd injection, it should be given 4 months after the infection has healed.
EU member states are also urging EU support to give a fourth dose to people over the age of 60. German Health Minister Lauterbach also cited Israeli data as saying the EU must develop vaccination strategies as soon as possible to reduce the risk of death from the epidemic.
In addition, the UK Joint Committee on Vaccination and Immunization recently recommended that the 5th injection should be further laid out.
On March 15, Zhang Wenhong, director of the Department of Infectious Diseases at Huashan Hospital affiliated to Fudan University, was interviewed by CCTV News "Theory of Relativity". When talking about the need to promote the fourth dose of vaccine in the mainland, he said: "In the future in China, I personally think that people with low immunity and advanced age are also likely to receive a fourth dose. But now there is no need to be so anxious, and there will be more international experience for us to use. ”
Source:
1.Coronavirus (COVID-19) Update: FDA Authorizes Second Booster Dose of Two COVID-19 Vaccines for Older and Immunocompromised Individuals. FDA
2.Second COVID vaccine booster significantly lowers death rate, Israeli study shows. Reuters
3.You may be eligible for a fourth COVID-19 vaccine. Here's what you need to know. ABC News
4.CDC recommends fourth Pfizer and Moderna Covid vaccine doses for people age 50 and older. CNBC
5.Fourth vaccine reduces COVID-19 deaths by 78% - study. The Jerusalem Post
6.Second Booster Vaccine and Covid-19 Mortality in Adults 60 to 100 Years Old. doi.org/10.21203/rs.3.rs-1478439/v1
7.4th Dose COVID mRNA Vaccines' Immunogenicity & Efficacy Against Omicron VOC. medRxiv. doi.org/10.1101/2022.02.15.22270948
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