The sharp rise in the rate of Covid-19 infection worldwide has triggered a scientific and ethical debate about the need to intensify injections to maintain protection from the virus.

This week, after a surge in cases related to the Delta variant, Israel Become the first country to provide boosters and authorize the third dose of BioNTech/Pfizer injections to adults with serious previous diseases. Other countries are considering whether and when to follow suit.

However, the science on whether an enhancer is needed to provide long-term immunity against Delta variants has so far been inconclusive. The World Health Organization has challenged the ethics of the third injection, and billions of people in low-income countries are still waiting for the first injection.

Rajiv Shah, chairman of the Rockefeller Foundation, said that he expects that as the virus continues to spread, there will be a need for intensified Covid injections in the next few years, just like the flu, which requires revaccinations every year.

“The task of vaccinating the world is not a one-off,” he told the Financial Times, adding that re-vaccinations “will become a universal reality.”

But it is unclear whether boosters are needed. A study conducted by Public Health England in May found that Delta variants dominate, and two injections of BioNTech/Pfizer injections are still 96% effective in preventing hospitalization. The study did find that Delta’s protection against symptomatic infections was reduced, but only slightly—88% effective, while the effective rate for the Alpha variant first discovered in Kent was 93%.

Leading vaccine manufacturers have stated that full vaccination is expected to provide immunity for at least 6 to 12 months. This week, Johnson & Johnson said that its mid-term results showed that its single vaccination produced a strong immune response eight months after vaccination, including against the Delta variant.

However, other studies have shown that the immune response generated by several current vaccines may last longer. Researchers at the University of Washington discovered in June that both Pfizer and Moderna’s mRNA vaccines produced “persistent“Immunity, the response is stronger in people who have previously been infected with the coronavirus and subsequently received full vaccination.

“The reason for using boosters is… the emergence of a new variant, the immune response of the vaccine no longer covers it,” said Michael Sage, associate dean of global health at the University of Alabama at Birmingham. “Now I don’t see this,” he said, adding that the number of people vaccinated due to Covid infection has not increased significantly.

Leading pharmaceutical companies seem to support fast boosters, with Pfizer and Moderna pushing the use of the third needle most strongly.

Last week, Pfizer said it plans to apply for an emergency use authorization from the U.S. Food and Drug Administration in August to provide people with a third dose. The announcement immediately caused a reaction from the FDA and the Centers for Disease Control, which stated in a joint statement that fully vaccinated individuals “do not need booster injections at this time.” “[We are] If it is scientifically proven that a booster dose is needed, prepare for a booster dose,” these agencies said.

The booster market provides huge opportunities for the pharmaceutical industry, and analysts estimate that Moderna and Pfizer alone have revenues of tens of billions of dollars.

In the UK, the Government’s Joint Committee on Vaccination and Immunization recently issued interim recommendations that millions of the most vulnerable people, especially the elderly with weaker immune responses, should be re-vaccinated in the fall.Final decision on whether to authorize Booster movement The UK stated that this will depend on the results of ongoing research on the duration of protection provided by the vaccine.

Azra Ghani, chair of infectious disease epidemiology at Imperial College London, said that in view of the adequate supply of doses in the UK, planning ahead is “pragmatic”.

Two-thirds of the adult population in the UK is fully vaccinated. In addition to the additional Pfizer vaccine ordered earlier this year, the government is still looking forward to the vaccine doses in its original procurement contracts with Novavax and Johnson & Johnson. The EU is also preparing to use boosters. It has ordered 1.8 billion doses of Pfizer and will be delivered from the end of this year to 2023.

The EU said it can donate any surplus. Despite this, the Director-General of the World Health Organization Tan Desai this week slammed the rich countries for ordering more vaccines, while the vast majority of developing countries cannot even get the first dose.

“The global gap in Covid-19 vaccine supply is very uneven and unfair,” Tedros said. “Some countries and regions have actually ordered millions of boosters, while other countries have not yet provided vaccinations for their health workers and the most vulnerable.”

Nearly half of the United States has been fully vaccinated, while the proportion of the total population in Africa is less than 2%. WHO.

“It’s really worrying morally,” said Michael Carome, director of the health research group at the advocacy group Public Citizen. “The real focus should be to send vaccines to countries where they are far behind, because in the end this will protect everyone.”

Ghani of Imperial College London said that deciding whether to boost is ultimately an act of political balance.

She said that for individual countries, “giving a booster dose is really not harmful.” However, on a global scale, “if these vaccines are given as the first and second doses to people who have not been vaccinated, more lives may be saved. Of course, this will help reduce transmission and make this country safer.”


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