Vaccination of Covid-19 in the Twenty-Five Years after the FDA Approval: Implications for the Prevention of Death and Hospitalization

An advisory committee unanimously recommended that manufacturers develop updated Covid vaccines, and the FDA greenlighted it. Based on the evidence at the time, FDA advisers initially recommended that the new vaccines target a lineage called JN.1, an Omicron offshoot. But the agency updated its guidance, asking vaccine makers to instead target the KP.2 strain, a descendant of the JN.1 variant, to more closely match circulating variants.

The new versions of the drugs are designed to cover the variant that has been circulating recently according to Dr. Peter Marks. The goal is that the closer we match the strain, the better the protection will be.

A surge of Covid-19 infections caused the US FDA to approve updated mRNA vaccines that target the current circulating variant of the coronaviruses.

The new 2024-2025 formula is meant to boost protection against hospitalization and death due to Covid. More than 850,000 people in the United States died because of Covid-19 in its lifetime, making it the leading cause of death in the country. Vaccination can also protect against long Covid, a chronic condition that lasts at least three months after an infection.

To maximize the chances of getting the best protection, people should wait at least two or three months since their last bout of COVID or their last shot to get one of the new vaccines, Marks says.

Marks says, “We are in a wave, so you would like to get protection against what is going on right now.” “So I would probably get vaccinated in as timely a manner as possible. Because right now the match is reasonably close. You’re probably going to get the most benefit you’re going to get from this vaccine against what’s currently circulating. So when this gets into pharmacies I will probably be on line as soon as it gets rolled out.”

Some people could consider waiting until September or October if they’re especially concerned about maximizing protection through the winter surge and over the holidays.

“In my opinion, everyone should get one of the new vaccines,” says Dr. George Diaz, chief of medicine at Providence Regional Medical Center Everett in Everett, Wash., and a spokesperson for the Infectious Disease Society of America. “Being vaccinated yourself will prevent transmission to other people. Reducing the spread of the disease will help some people in the community. So you’re not just helping yourself but also helping others.”

Some wonder if everyone should receive another shot because they have gotten enough immunity from all the shots and infections they have gotten to protect them from getting sick.

Insured people can get all three vaccines for free if they get their shot from an in-network provider. But a federal program that paid for the vaccines for uninsured adults expired.

“In the public health community we’re very concerned about how they will access protection and looking for ways for how we’re going to solve that problem,” says Dr. Kelly Moore, who runs Immunize.org, an advocacy group. The uninsured are least likely to be able to afford an illness because of missing work and staying at home.

“Any natural immunity or vaccine immunity from 2023 has reached a nadir,” Hudson says. “This is sort of a perfect storm for a more infectious form of Covid.”

The winter is when the largest surge of respiratory viruses occurs. The surge in Covid is due to the emergence of new strains and waning protection of the previous vaccine, and it tends to peak in the winter and summer.

Like the influenza virus, SARS-CoV-2 is constantly changing. And similar to how flu vaccines are updated every year to adapt to the virus’s changing structure, the Covid vaccines are also being updated. It is difficult to predict which variant will be dominant by the time the vaccine comes out due to the rapid change of the SARS- CoV-2. “It’s spinning through variants more quickly than what we’re seeing with flu,” she says.