Israel: Fourth dose of Pfizer vaccine has limited efficacy against Omicron

Two weeks after inoculation, the antibody level in the experimental group increased, but the protective effect on omicron was limited
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From the first to the second, third and fourth doses, the world is constantly updating vaccination schedules in response to the disruption of new coronavirus mutant strains
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However, Israel, as the first country in the world to inject the fourth dose of the vaccine nationwide, preliminary research results published on the 17th showed that the fourth dose of the vaccine jointly developed by Pfizer and BioNTech was limited
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 relatively little protection

According to a Reuters report on the 17th, 154 medical staff from the Sheba Medical Center in Tel Aviv, Israel, participated in the trial
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At present, these are only preliminary research results and have not been officially released
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The researchers found that two weeks after the fourth dose of Pfizer's vaccine, antibody levels in the test subjects rose, but protection against omicron was limited
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After the fourth dose of Pfizer's vaccine, the number of antibodies in the body was higher than after three doses, said Gili Regev-Yochay, the trial's lead investigator
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However, the fourth attack provided only partial defense against Omegaron, and was relatively less protective and more effective against previous Delta strains
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The study also showed that the trial population who remained infected with omicron after the fourth dose of the vaccine had only mild or no symptoms, meaning the fourth dose of the vaccine was still significantly effective in preventing severe disease
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Israeli researchers also conducted a trial with 120 volunteers who had previously received three doses of the Moderna vaccine but now received a fourth dose
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The results showed a similar increase in antibody levels in people who received Moderna's vaccine compared to those who received Pfizer's fourth dose of the vaccine a week after the trial began
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Regev Uzia told the media that it was a good vaccine and that a fourth dose for the most vulnerable was the right decision, as it may have additional benefits, but the findings did not support the rollout of the policy across the country
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Israel is one of the fastest countries in the world to roll out a vaccine
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According to the Israeli Ministry of Health, more than 500,000 people in the country have received the fourth dose of the vaccine
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Vaccine strategy draws attention

As the global epidemic continues to spread, Omicron's amazing transmission ability is also worrying
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Numerous studies have shown that in the process of constant mutation, the virus can "learn" how to evade immunity, thereby weakening the protective effect of the vaccine
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Existing research data show that mRNA vaccines have a 90%-95% preventive effect on the initially discovered new coronavirus
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Data from the South African study also showed that the preventive effect of two doses of Pfizer's vaccine against Omicron dropped to 33 percent
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The data sparked discussions about vaccine development strategies, including the need to produce targeted vaccines against specific mutant strains, the popular science journal Scientific American recently wrote

Last week, Pfizer announced that a vaccine against Omicron, which is currently in production, could be available in March

One view is that, given that existing vaccines are still effective in preventing serious illness and death, specially made vaccines are of little use

Some experts pointed out that although the introduction of vaccines will take time, the rate of mutation of the virus may be faster than that of vaccine development

Therefore, the current vaccine strategy of "chasing the virus strain" may develop into a "game of whack-a-mole"

According to experts, it usually takes 4 to 6 months to develop a vaccine, but it only takes 2 months for the beta mutants to appear and disappear

Omicron was discovered in South Africa last November, but the number of cases in South Africa has now declined
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Some research institutes believe that new strains other than Omicron may emerge in the coming months, and that developing a universal vaccine may be a better direction than developing a targeted vaccine against an unknown mutated virus
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Israel: Fourth dose of Pfizer vaccine has limited effect against Omicron

(Source: Internet, reference only)

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