The U.S. Food and Drug Administration on Thursday approved COVID-19 vaccines from Pfizer and Moderna.
It’s the third time since the first series that the vaccine has been updated to match circulating strains of the virus. A vaccine is expected to be available within days. The FDA has yet to approve a third vaccine, from pharmaceutical company Novavax.
The timing of the new vaccine is important, as last year’s rollout was in mid-September while much of the U.S. was still in the midst of the summer COVID-19 pandemic. As of Monday, the Centers for Disease Control and Prevention reported that the number of people testing positive for COVID-19 continues to rise, and emergency room visits due to COVID-19 have also increased since mid-May. Hospitalizations are also on the rise.
Here’s what you need to know about the updated vaccine.
How is the new coronavirus vaccine different?
The new vaccines from Pfizer and Moderna are designed to target the KP.2 strain, a descendant of the highly contagious JN.1 variant that began circulating in the U.S. last winter. Drugmakers began making the new vaccines in June after the FDA ordered them to revamp their formulations to match the version of the virus spreading in the U.S.
A third vaccine, from pharmaceutical company Novavax, has been modified to target the JN.1 strain, both of which have been largely eliminated from circulation, according to the CDC.
As of Saturday, a sister strain called KP.3.1.1 accounted for about 36% of all novel coronavirus infections, while another sister strain, KP.3, accounted for about 17%.
It is unclear how effective the vaccines will be against the new variants, but experts are hopeful they will be effective in preventing severe illness.
A Pfizer spokesperson told NBC News that data submitted to the FDA shows the company’s vaccine produces a “significantly improved” immune response against several currently circulating variants, including KP.3, compared to previous versions of the vaccine.
John Moore, a professor of microbiology and immunology at Weill Cornell Medical College, said there are “very small sequence differences” between the variants.
A paper published in the journal Infectious Diseases this month said KP.3.1.1 shares similarities with JN.1 and KP.2 but has several more mutations that may allow it to spread more easily.
“These changes are all incremental; they don’t change the big picture,” Moore says. “KP.3.1.1 is just one step on the road to greater transmissibility for the entire Omicron lineage.”
Who should get the COVID-19 vaccine?
In a previous interview, Dr. Ashish Jha, dean of the Brown University School of Public Health and a former White House COVID-19 response coordinator, said COVID-19 is likely endemic in the U.S., meaning the virus is following a “relatively predictable pattern that’s going to continue for a very long time.”
This means that, just like an annual flu shot, we will be getting a COVID-19 vaccine that will be updated every year to prevent mutations and waning immunity.
According to CDC data, as of May 11, only 22.5% of adults had received last year’s updated COVID-19 vaccine. Only 14.4% of children ages 6 months to 17 were vaccinated.
The CDC recommended this fall that all Americans age 6 months and older get the new vaccine.
But Dr. Isaac Bogoch, an infectious disease specialist at the University of Toronto, said it’s difficult to make blanket recommendations about who should get the vaccine, especially for healthy younger adults.
“It’s fair to say that the vaccine is still beneficial at the individual level and, to some extent, at the community level,” he said.
Bogoch said it’s crucial that people at highest risk of severe illness, including those over 65, those with weakened immune systems and those with underlying health conditions such as heart disease or obesity, get the vaccine.
“The main aim of the vaccine is to protect the most vulnerable from serious outcomes such as hospitalization and death,” he said.
When should I get the new coronavirus vaccine?
Millions of Americans have been infected with the new coronavirus over the past few weeks and months, and the upside of the summer outbreak is that those who have recently recovered will have a stronger immune system to fight off future infections.
Because the vaccine is available sooner this year than last, the question of timing for maximum protection over the winter is more urgent: CDC guidance says that if you have recently been infected with COVID-19, “you may consider delaying vaccination by 3 months.”
Experts are urging people at high risk for severe illness to get the vaccine as soon as it’s available to them, because infection may not provide as much protection as vaccination, said Dr. Ofer Levy, director of the Precision Vaccine Program at Boston Children’s Hospital.
Protection from infection depends on the severity of the infection, the strain, and the individual’s age and health.
For young, healthy people, getting the vaccine soon after recovering from an infection may not be as beneficial, said Akiko Iwasaki, a professor of immunology at the Yale University School of Medicine: High levels of antibodies from a recent infection could prevent the vaccine from stimulating new immune cells.
“If you already have a lot of antibodies circulating in your body, those antibodies will block the effectiveness of[the vaccine],” she said. “That’s one of the reasons why we don’t recommend getting the vaccine immediately after COVID-19 infection.”
Dr. Paul Sachs, clinical director of infectious diseases at Brigham and Women’s Hospital in Boston, said there’s no harm in getting vaccinated now, but since COVID-19 cases tend to rise around November, it may be wise to wait.
“Assuming that continues to be the case this year, the best time would be around October, when people are getting their flu shots,” Sachs said.
There is no risk in getting vaccinated right away, but the initial protection the vaccine provides may not last through the expected winter wave of infections, Sachs said.
“Fortunately, we are not at high risk for severe disease because we have immunity from previous vaccinations or exposure to COVID-19,” he said, “but if we want to avoid infection altogether, the surge of antibodies that occurs one to three weeks after vaccination is the most effective.”
Connecticut Public Health Director Dr. Manisha Juthani said people who have recently been infected with COVID-19 can wait several months before getting the latest vaccine.
“Your immunity weakens when you get COVID and when you get the vaccine,” Jutani said during a press conference with the Association of State and Local Health Officials on Wednesday ahead of the winter respiratory virus season. “If you’re not willing to get the vaccine right away, wait about three months from when you got COVID, and especially with the holiday season coming up, get it before any big holidays or when you might be gathering in public.”
“If you are really keen to get vaccinated as soon as it becomes available to you, then of course you can get it even if you get COVID this summer,” she added. “There’s no reason why you can’t get it in September or October.”
Data from coronavirus vaccines so far suggests that even if the vaccine is closely matched to the circulating strain, the initial protection against infection peaks about a month after vaccination and then begins to wane over several months.
The good news is that protection against severe illness remains strong for a much longer period, Iwasaki said.
Ultimately, she said, you never know when you might contract the virus.
“It’s a kind of dangerous calculation because a wave just means that there are a lot of infected people in a population, but at an individual level you could be infected tomorrow,” she says, “so it’s very difficult to predict when is the best time to be infected.”
Iwasaki has not been infected for a while and has not received a booster vaccination, so he plans to get vaccinated as soon as possible.
Sacks advises patients to wait two to three months after recovery before getting their next shot.
“Actually, getting infected actually strengthens your own immunity somewhat,” he says.
What are the side effects of the new coronavirus vaccine?
As with other versions of the COVID-19 vaccine and the flu shot, the most common reaction is pain at the injection site. Other side effects include:
Fatigue, headache, muscle pain, chills, fever, nausea
Side effects usually subside within a few days, and serious side effects, such as a life-threatening allergic reaction called anaphylaxis, are rare, according to the CDC.
What is the cost?
Pfizer, Moderna and Novavax are charging up to $150 per dose of their coronavirus vaccine, according to data from the Centers for Medicare and Medicaid Services.
Jennifer Cates, director of the Global Health and HIV Policy Program, said the majority of people with public and private health insurance should have no out-of-pocket costs for the latest COVID-19 vaccines as long as they continue to use in-network providers.
Medicare and Medicaid are required to make the vaccines free for patients, and the Affordable Care Act, also known as Obamacare, requires private insurers to cover all vaccines recommended by the CDC’s vaccine panel and director.
But Cates added that the ACA’s requirements don’t apply to vested plans or short-term health insurance plans that existed before the ACA was signed into law.
“People with these plans may have to pay for the COVID vaccine themselves, or the vaccine may not be covered at all,” she said.
Children who don’t have insurance can get the vaccine for free through the government-run Vaccine for Children Program.
For adults without health insurance, the situation is a bit different: The CDC’s Bridge Access Program, which has paid for vaccinations for uninsured adults, is set to end in August due to a lack of funding.
Cates said once the funding runs out, uninsured people may be able to get COVID-19 vaccines for free through local health centers and other safety-net providers that participate in the adult Section 317 vaccine program. Section 317 is a federal initiative that provides funding to states to provide vaccines to uninsured or underinsured adults.
“Some state and local health departments may also have limited supplies available for the uninsured, but supplies will be very limited,” Cates said.
