7 of the biggest medical breakthroughs in 2023

From new vaccines to the first drugs of their kind for hard-to-treat disorders, 2023 has been a year full of medical breakthroughs.

They offer opportunities for people to protect themselves from diseases, slow down the effects of others and even incorporate artificial intelligence into cancer diagnoses.

Here are seven of the biggest innovations in the health and science space this year.

New RSV vaccines and immunizations

For the first time ever, after years of setbacks, there are multiple vaccines and shots available for several different groups to prevent RSV.

For adults over age 60, who are at higher risk for serious complications from RSV because immune systems weaken with age, the U.S. Food and Drug Administration (FDA) approved two vaccines.

"So much focus is placed on flu and now COVID. but, each year in the U.S., we see tens of thousands of older adults hospitalized from RSV, thousands die from RSV complications," said Dr. John Brownstein, an epidemiologist and chief innovation officer at Boston Children's Hospital and an ABC News contributor.

"It still has significant public health consequences for those that are most vulnerable, and so now having a high efficacy vaccine is really a tremendous breakthrough for the last year and I think will have significant public health benefit for years to come," he added.

The FDA also approved a maternal RSV vaccine, which is given to pregnant mothers in the third trimester between 32 weeks' and 36 weeks' gestation and is designed to pass antibodies to babies in the womb. It can provide protection from severe illness through the first six months of life.

Lastly, for babies under 8 months old, there are two monoclonal antibody shots available. Monoclonal antibodies are laboratory-made proteins that mimic the body's ability to fight off pathogens. They are different from vaccines, which stimulate the immune system.

1st CRISPR gene-editing technique to treat sickle cell

Earlier this month, the FDA approved two gene therapies to treat sickle cell disease (SCD), including the first CRISPR gene-editing therapy.

SCD is a genetic condition in which red blood cells have a crescent, or sickle, shape, causing them to be hard and sticky.

"It is a disease that really touches every organ in the body," Dr. Sharl Azar, medical director of the Comprehensive Sickle Cell Disease Treatment Center at Massachusetts General Hospital, told ABC News. "A quarter of our patients will have had a stroke by the time they're in their 40s. Many of our patients will have had their first joint replacement by the time they're in their 30s. Many others will have had their first heart attack in their 20s."

"If the disease goes unchecked, it can lead to blindness, it can lead to dialysis dependence and most of our patients may not see their 45th or 50th birthday," he continued.

One of these therapies, Lyfgenia, uses a piece of a virus to deliver a gene for fetal hemoglobin, which prevents blood cells from sticking together and constricting blood flow, which is delivered back into the patient.

The other therapy, Casgevy, used CRISPR/Cas9 to genetically edit the stem cells to produce more fetal hemoglobin, which are then also put back into the patient

"From a scientific and medical standpoint, both of these therapies aim to do the same thing, they just do it in a slightly different way," Azar said. "So, the important thing to emphasize here is that these are not a cure for sickle cell disease. The patients will still have sickle cell disease on the other side of the intervention. The hope is that they will just have a milder form of the disease, where they can see a lot less pain and hopefully fewer complications and hopefully even a longer life."

Over-the-counter birth control pill

In July, the FDA approved the first over-the-counter birth control pill, meaning it can be sold without a prescription.

Called Opill by French drugmaker HRA Pharma and its parent company Perrigo, public health experts have said it will broaden birth control access for millions of people in the United States.

Opill is a progestin-only pill -- sometimes called the "minipill", meaning it doesn't contain estrogen like combination birth control pills. Doctors say progestin-only pills pose fewer medical risks than combination pills.

The drug is expected to appear on shelves at convenience stores, grocery chains and online in early 2024.

Scientists pinpoint possible cause of morning sickness

Morning sickness is an extremely common early symptom of pregnancy, with up to 80% of pregnant women experiencing it in the first trimester -- and now researchers believe they have discovered the cause.

A team mainly from the U.S., U.K. and Sri Lanka discovered a link between a hormone called GDF15, produced by the fetus in the placenta, and morning sickness.

Results, published earlier this month in the journal Nature, found women with severe nausea and vomiting and blood levels of GDF15 during the first trimester that were significantly higher compared to women who didn't experience sickness.

Additionally, women who are more sensitive to the hormone become the sickest, which may explain the small percentage of women who suffer an extreme form of morning sickness hyperemesis gravidarum, which is the leading cause of hospitalization in the early stage of pregnancy and famously experienced by Catherine, Princess of Wales during all three of her pregnancies.

Researchers said the finding could help treat women with morning sickness, especially severe forms, by lowering levels of the hormone during pregnancy.

First drug fully approved by the FDA to treat Alzheimer's

In the past, Alzheimer's disease treatment has been marked by several drugs that have failed clinical trials but, in July, the FDA granted full approval for a new drug called Leqembi.

Manufactured by the pharmaceutical companies Eisai and Biogen, it is the first drug of its kind that has shown to slow cognitive decline in early Alzheimer's patients.

Leqembi works by targeting amyloid beta, the main component of the amyloid plaques found in the brains of Alzheimer's patients and affects memory and thought. It marks the plaques for clearance by the body's immune system, which slows Alzheimer's symptoms.

"It's a significant milestone in Alzheimer's disease treatment," Brownstein said. "It is a very big step in giving individuals suffering from this disease more time, and clinical trials have shown to modestly slow cognitive decline, especially in people with early Alzheimer's disease, and so by slowing cognitive decline, that drug could provide individuals more time to engage in activities that they enjoy."

Brownstein noted that there are still questions surrounding the drug's accessibility. The full approval means Medicare can start covering the cost of treatment for patients, making it more widely available, but that's for a subset of patients.

"This drug, like many others, requires substantial investment for research and development, and so, because of that, companies use drug pricing to recover the costs associated with developing and bringing these drugs to market," he said. "Unfortunately, that pricing, that means that this drug will be out of reach for some, and that's really something that needs to be addressed because of course, this drug should be available to anyone suffering from this disease."

An mRNA vaccine to treat pancreatic cancer

A research team funded by the National Institutes of Health (NIH) has developed a personalized mRNA vaccine with partners at BioNTech, against pancreatic cancer, one of the deadliest forms of cancer in the U.S.

BioNTech performed gene sequencing on more samples to identify neoantigens -- proteins that are unique to cancer cells – that may stimulate an immune response.

In early clinical trials, patients received a drug that inhibits cancer cells from suppressing the immune system, then were given their personalized vaccine split in nine doses over many months.

Eighteen of the 19 patients successfully had vaccines created for them and 16 were healthy enough to receive at least some of the doses, according to the NIH.

About half of the patients saw the vaccine trigger T cells, a type of immune system cell that destroys infected cells, that targeted the specific cancer cells in each patient.

Among the patients who saw the strong immune system response, the cancer did not return after a year and a half of treatment, including chemotherapy. In those who did not have a strong immune system response, the caner retuned within a year, according to results published earlier this year in the journal Nature.

"It's exciting to see that a personalized vaccine could enlist the immune system to fight pancreatic cancer—which urgently needs better treatments," Dr. Vinod Balachandran, a surgical oncologist from Memorial Sloan Kettering Cancer Center, said in a statement. "It's also motivating as we may be able to use such personalized vaccines to treat other deadly cancers."

AI boosts breast cancer detection rates

Artificial intelligence (AI) has been increasingly used in scientific trials, and a new tool developed this year is helping spot more breast cancer than human screenings.

The tool, named Mia and developed by Imperial College London and Kheiron Medical Technologies detected 13% more early breast cancers.

Across the two pilot phases and the live roll out, Mia detected 24 more cancers and led to 70 more women being recalled, according to a release from Imperial College London.

Of the women who were recalled, additional cancers were found, which raised cancer detection rates by 13%.

"These results have exceeded our expectations," Dr Ben Glocker, a professor in machine learning for imaging at ICL, said in a statement. "These results have exceeded our expectations. Our study shows that using AI can act as an effective safety net -- a tool to prevent subtler signs of cancer falling through the cracks. Seeing firsthand that the use of AI could substantially reduce the rate of missed cancers in breast screening is massive, and a major boost for our mission to transform cancer care with AI technology."