Is a fourth dose of the vaccine necessary?

The Israeli Experience: Useful for the Elderly

  When talking about the need to promote the fourth dose of the new crown vaccine a few days ago, Zhang Wenhong, director of the Department of Infectious Diseases at Huashan Hospital Affiliated to Fudan University in Shanghai, said that he can learn from Israel's experience.

He said: "Recently, Israel and Singapore are both deploying the fourth shot, and my country will also consider the fourth shot in the future."

  In January of this year, Israel, which is one of the best in vaccination, once again took the lead in providing the fourth dose of the new crown vaccine to people over 60 years old in the world.

But unlike the first three doses of the vaccine, the fourth dose was full of controversy from the start and was deemed unnecessary by many, including experts.

  With the launch of the fourth dose of vaccination in European and American countries, more scientists have joined this heated debate.

But the latest news from Israel may help ease the debate.

An Israeli study showed that for the elderly or immunocompromised people, the fourth dose was not only useful, but also life-saving: Those who received the fourth dose of the vaccine had a 78% lower mortality rate compared with those who received the three doses.

  Song Jing, a resident scientist at the Benaroya Research Institute in the United States and a doctor of immunology at the Hebrew University of Jerusalem in Israel, told Yicai.com that ordinary people may not need to take the fourth dose, but for those who need to focus on The fourth needle is crucial for protecting older adults.

  reduce mortality in the elderly

  Arnon Gutfeld, an 82-year-old professor emeritus at Tel Aviv University in Israel, told Yicai.com that when the Israeli Ministry of Health announced the fourth dose in January, he hurried to get vaccinated.

He said the fourth dose is now well received among older Israelis, with many receiving the fourth dose.

  The latest data supports his view, and Professor Gutfeld said he was pleased to see older Israelis making the right choice.

Israel's largest health service organization, Clalit, and other research institutions recently announced that after a follow-up survey of 560,000 people over the age of 60, they found that compared with those who received only three doses of the vaccine, the fourth dose was administered. After the vaccine, the death rate in the elderly was significantly reduced by 78%.

  The study surveyed 560,000 older adults, with a median age of 73, and 53 percent were women.

Among them, 330,000 people received the fourth dose, and 92 people died (due to infection with the new crown); as a control, 235,000 people did not receive the fourth dose, and 232 people died.

  Sapir College researcher Ronen Arbel, who led the study, said the main conclusion of the study was that a fourth dose of the vaccine could save a life.

He said that while it was difficult to estimate how many people the fourth dose would save globally, it could have saved hundreds of lives in Israel alone.

  In January of this year, Israel ranked first in the world with a daily per capita infection rate of 0.6%, and the elderly in Israel are fully exposed to the risk of contracting the new coronavirus.

This situation also increases the credibility of the study.

  Due to the transmission characteristics of the Omicron strain and the relaxation of epidemic control in Israel, there have been a total of 3.88 million infections in Israel's population of more than 9 million.

According to the epidemic data released by the Ministry of Health on the 28th, there were 9,857 new confirmed cases of the new crown in the country in the past 24 hours.

A total of 10,485 deaths have been recorded.

  Albert emphasized that because the Omicron strain is more contagious, the fourth dose may not be satisfactory in preventing infection, but it is effective in preventing severe and fatal cases.

  He suggested that other countries could start considering a fourth dose for immune-vulnerable groups.

But he also pointed out that the problem of unfair distribution of vaccines around the world has not been resolved, and many places have not yet had the conditions to promote the third or fourth dose.

  The fourth dose of the vaccine is "minimal" to protect against the new coronavirus, according to the results of a March 17 study from Israel's Sheba Medical Center.

  Of the roughly 600 trial participants, 270 received a fourth dose of either the Pfizer or Moderna vaccine, said Dr. Gili Regev-Yochay, director of the division of infection prevention and control at Sheba Medical Center.

The levels of both immunoglobulin G (IgG) antibodies and neutralizing antibodies in their bodies were essentially similar to those measured one month after the third dose of the vaccine.

  The results suggest that for healthy young adults who received three doses of the vaccine, the fourth dose of the vaccine was not significantly effective, providing only "mild protection" against symptomatic infection.

  The battle for the fourth dose of the new crown vaccine

  On March 28, Israeli Prime Minister Bennett announced that he was infected with the new crown virus.

However, this news did not cause waves. The first financial reporter checked the Israeli mainstream media that day, and the news not only did not make the headlines, but also did not reflect on the first screen of the webpage.

  Ms. Rifka, who lives in Israel, told the First Financial Reporter that in fact, there are not many friends around her who have not been infected with the new crown. She has seen the illness of the people around her, so everyone is not worried.

  In Israel, more than 6.7 million people have received at least one dose of the new crown vaccine, and the country's third dose has now reached 56.7%.

Bennett has also received three doses of the new crown vaccine.

  There was a lot of debate in Israel, which took the first step, whether to take the fourth dose, and even the Israeli Ministry of Health was a little hesitant at first.

  On December 22, 2021, the expert advisory group of the Israeli Ministry of Health recommended the fourth dose of the new crown vaccine for people over 60 years old and medical staff, and the fourth dose should be more than 4 months away from the third dose.

  Advisory group member Professor Galia Rahav said the decision was not easy because there was no complete data on the immune effect of the fourth dose of the vaccine, "which was the same as when the third dose was introduced, but at the same time, The global epidemic data is terrible. If you don’t act now, you will miss the opportunity to get in the car.” A research paper in the journal Immunity at the time showed that the fourth dose may not improve immunity as much as the first. dose and second dose.

  Eyal Leshem, an infectious disease specialist at the Sheba Medical Center in Israel, also said that in the long run, two or three doses of the new crown vaccine will provide most people with good protection against severe illness.

  He also pointed out that if the power of the mutant strain becomes smaller and smaller in the future and becomes "flu-like", it is likely that supplementary supplements will not be needed.

  However, the expert advisory panel's recommendation did not receive fast-track approval from the Israeli Ministry of Health.

The Ministry of Health said they still need to think about it.

But finally on January 2, Bennett announced that the fourth dose had been approved by the Department of Health.

  Israel's Ministry of Health said its final decision was based on two considerations.

The first is epidemiological research showing that people over 60 years of age have a three-fold increased risk of infection four months after vaccination, and Omicron has a greater ability to escape.

Studies from the Centers for Disease Control and Prevention have shown that immunity levels from vaccine boosters decline over time.

  Followed by the first vaccinated health care workers, one week after the fourth dose, the antibody level increased fourfold without significant adverse effects.

  The U.S. Food and Drug Administration (FDA) is also expected to approve a fourth dose of the vaccine for those over 50 soon.

Data from the U.S. Centers for Disease Control and Prevention showed that the effectiveness of the third dose of vaccine in preventing hospitalizations dropped to 78 percent in the fourth month.

  Fauci, an American infectious disease expert, said that the 78% effective rate is still a very safe range, and it is not yet time to fully promote the fourth dose of the vaccine; for people with normal immune function, the third dose can provide High level of protection.

But immunocompromised people should get the fourth dose, because the vaccine has insufficient immune activation ability in their body and needs to be further boosted.

  The British Joint Committee on Vaccination and Immunization even suggested recently that the UK should further deploy the autumn booster vaccination, that is, the fifth dose of the vaccine.

At that time, the public may once again ask questions, how many new crown vaccines do ordinary people need to get through the new crown epidemic?

  Author: Qian Xiaoyan

Keywords: