The second booster dose of the Pfizer-BioNTech and Moderna Covid vaccines was approved by the U.S. officials last week in an effort to bolster waning immunity ahead of a potential surge of cases driven by the infectious BA.2 omicron subvariant.

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Experts warn that we can't boost our way out of the Covid-19 epidemic.

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The second booster shot for Moderna and Pfizer's Covid-19 vaccine for people 50 and older was approved by the Food and Drug Administration on Tuesday.

A fourth dose appears to be beneficial at preventing serious illness in older or high-risk people.

Professor Dan Barouch, a vaccine researcher at Harvard Medical School, told Forbes that boosting every three to six months is not a good idea.

It is simply not possible for poorer countries to boost frequently.

Professor Deepta Bhattacharya, an immunologist at the University of Arizona, said we need more bang for the buck from these vaccines.

If booster shots are updated to match the circulating variant of coronaviruses, we could buy more time between shots.

There are new vaccines. Pfizer, Moderna, Johnson and Novavax are working on o-micron-specific shots to address fading effectiveness against the variant. The worst of omicron could be behind us by the time these vaccines are available. After the variant of the virus stopped being one of the most concerning forms, the company abandoned efforts to create a vaccine. Simply retooling vaccines to counter the latest variant can be too slow and leaves a vulnerable period as it is produced, tested, cleared, manufactured and distributed. Dr. John Swartzberg, an infectious disease expert at the University of California at Berkeley, told Forbes he hopes we will find a way to make the vaccine give long- lasting immunity. Several efforts are underway to create a universal vaccine which would target parts of the virus crucial to its function and don't change across variant.

Crucial Quote

John P. Moore told Forbes in an email that he doesn't think we can boost our way out of the epidemic. Moore pointed to a number of questions that need to be addressed over time, including whether there will be new waves, how long any wave will last, and how we emphasize protection against serious illness in the future.

Contra

Some experts don't think updated vaccines are necessary. Moore told Forbes that the shots based on the virus can be used for a long time yet. Moore said that animal studies show that boosting with the original vaccine is the better option, and that few unvaccinated people are likely to change their minds and get the shot. It is not clear at this point that we need to update our current vaccine, and there is evidence that the vaccine gives broad-based immunity.

Key Background

The U.S. has joined a growing number of countries. In Israel, experts advise the government to make fourth doses available to all adults. The practice of successive boosting with Covid has been developed in real time, and initial vaccine trials were not able to assess how durable the protection was beyond a few months. According to data, the Johnson & Johnson vaccine is now preventing infections and serious illness as well as better than Moderna and Pfizer shots. The primary goals of vaccination are preventing serious illness, hospitalization and death, not stopping infections, according to Adalja. Studies assessing immunity based on antibodies do not capture the full picture and other parts of the immune system, like T cells, can still help prevent serious illness even if they can't stop infections.

Do you need a second covid booster shot? The experts are not on the same page. (Forbes)

The next move of the coronaviruses

Scientists have been looking for new variations of the vaccine. They're looking for a universal coronaviruses vaccine. The Washington Post has an article about it.

Live updates on the coronaviruses.